'<<> 9 A UNtTED STATES DEPARTMENT OF COMMERCE PUBLICATION SCIENCE AND ENGINEERING J.S. DEPARTMENT OF COMMERCE ENVIRONMENTAL SCIENCE SERVICES ADMINISTRATION SCIENCE AND ENGINEERING July 1, 19B"7 to June 30, 1SBS -jjENTo^^ Q. s o *w5 o a a> o to U.S. DEPARTMENT OF COMMERCE Maurice H. Stans, Secretary Rocco C. Siciliano, Under Secretary Myron Tribus, Assistant Secretary for Science and Technology ENVIRONMENTAL SCIENCE SERVICES ADMINISTRATION Robert M. White, Administrator Rockville, Md. 1970 UDC 528 :550.3 :551.46 :551.5 :556 :62 :65.012.1 / .2 :06.055.5 (047.1 ) ESSA 528 Geodesy, cartography 550.3 Geophysics, seismology, geomagnetism 551.46 Physical oceanography 551.5 Meteorology, climatology 556 Hydrology 62 Engineering 65.012.1 Research operations 65.012.2 Plans and programs 06.555.5 Biennial reports (047.1) Progress reports Library of Congress Card No. 73-607953 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $1.50, paper cover FOREWORD The first ESSA Science and Engineering was published in 1968 and covered ESSA's progress from its July 13, 1965, beginning through June 30, 1967. The present publication is the second in this biennial ESSA Science and Engineering series and describes the course our work has taken over the two years from July 1, 1967, through June 30, 1969. I hope that the descriptions of ESSA's work will indicate some of the ways in which the pro- grams and services of our agency have matched the human and social needs that generate them. It is my hope also that this volume will serve as a means of disseminating information about our activities in a form useful to scientists, engineers, and all others who may be interested in the physi- cal environmental sciences. ROBERT M. WHITE, Administrator Rockville, Maryland June 26, 1970 PREFACE The Environmental Science Services Administration's science and engineering programs during FY 68 and FY 69 are described in this publication. The first three chapters — Highlights, Organization and Program Areas, and Goals — provide a pre- view of ESSA's program activities for the reporting period, give details on the reorganizations within ESSA during the past two years and the program structure, and describe the goal areas through which research and development is utilized by ESSA to solve key problems involving the measurement, description, and prediction of the physical environment. Each of the other six remaining chapters deal with research and development activities within ESSA's service areas: Weather Forecasts and Warnings; Earth Description, Mapping, and Charting; Marine Description, Mapping, and Charting; Telecommunications and Space Services; Environmental Satellite Services; and Environment Data and Information Services. All of ESSA's science and engineering activities, including basic, applied, and developmental re- search, are incorporated in their relevant chapter. Data services for all ESSA pro- grams, however, are discussed in a separate chapter rather than within the individual program areas; also included in this chapter is a discussion of ESSA's effort in scientific and technical communication. All references made to organizations within ESSA refer to those structures as depicted in the organizational chart (Chapter 2) that have existed during the two fiscal years encompassed within this publication. Because of the changing nature of environmental science and technology, ESSA's organizational structure must remain dynamic in order to meet demands placed upon it for new services. Hence, additional organizational changes within ESSA will continue to occur in the future. Production of a publication of this type is always a collective venture involv- ing the cooperation of a number of individuals. Especially, I would like to thank Mr. John Bernick for editorial services; Mrs. Bertha Sladek for manuscript typing; Mr. Edward Koehler for production coordination; and Messrs. Max Chesy, William Welsh, James Schick, and Jack Rausch for graphic support. I am also indebted to Mr. Robert de Chancenotte and Mrs. BevAnne Ross of the American Meteorological Society for index preparation. 'Lf^^iZ^^ k JACK N. SHUMAN Technical Information Specialist CONTENTS Page Foreword iii Preface v 1. Highlights 1 2. Organization and Program Areas 15 3. Goals 21 4. Weather Forecasts and Warnings 27 Basic Weather Services 27 Public Weather Forecasts 36 Hurricane and Tornado Warnings 38 Agricultural Weather Services 44 Air Pollution Service 45 Weather Modification 48 Fire Weather Service 51 Aviation Weather Services 52 Marine Weather Services 54 River and Flood Prediction and Warning 57 O . Earth Description, Mapping, and Charting 61 Geodesy 62 Geomagnetism 68 Seismology 71 Cartography 79 Marine Geophysics 80 6. Marine Description, Mapping, and Charting 83 Marine Navigation, Mapping, and Charting 83 Oceanography 85 7. Telecommunications and Space Services 91 Telecommunications _ 92 Aeronomy and Upper Atmosphere 100 Space Environment 102 O. Environmental Satellite Services 105 9. Environmental Data and Information Services II3 Glossary of Acronyms __ 123 Index 125 Digitized by the Internet Archive in 2012 with funding from LYRASIS IVIembers and Sloan Foundation http://archive.org/details/essascienceengiOOunit 1 HIGHLIGHTS Fields of interest involving the earth, its oceans, its at- mosphere, and the space surrounding the earth are the concern of ESSA — ^Environmental Science Services Admin- istration. ESSA is primarily an organization for providing service through its various components to other Government agencies and to the general public, but it also has the responsibility for initiating research related to environ- mental problems. Scientists and engineers of ESSA provide service and initiate research into the broad spectrum of environmental problems, ranging from earth-air and sea-air interactions to improved environmental prediction. The first published review of ESSA's scientific and engi- neering accomplishments covered the period from July 13, 1965, through June 30, 1967. The accomplishments cover- ing the reporting period from July 1, 1967, through June 30, 1969— Fiscal Years 1968 and 1969 (FY 68 and FY 69) — are the subject of this second publication. Organization and Management For the 4 years of its existence, ESSA has operated with the same basic organizational structure. However, a num- ber of internal reorganizations have occurred. Two of the six major reorganizations during the reporting period of this publication were within ESSA Headquarters. The other reorganizations were within four of the five Major Line Components (MLC) — ^Weather Bureau, Coast and Geo- detic Survey, National Environmental Satellite Center, En- vironmental Data Service, and Research Laboratories. De- tails of all reorganizations are found in Chapter 2. A com- plete discussion of the basic organizational structure of ESSA is in the first publication, ESSA Science and Engi- neering — July 13, 1965 to June 30, 1967. The ESSA Headquarters staff had its first major reor- ganization on September 8, 1967. At that time, three Offices — Planning and Programs Evaluation, Science and Engi- neering, and User Affairs — were combined into a single Office of Plans and Programs, headed by an Assistant Ad- ministrator for Plans and Programs. A second major Headquarters reorganization occurred on January 31, 1969. On that date, the Management Sys- tems Division was created within the Office of Administra- tion and Technical Services (ADTECH) from the merger of two Divisions — the Management and Organization Di- vision and the Management Systems and Information Division. The first reorganization by an MLC took place within the National Environmental Satellite Center (NESC) on September 22, 1967, with the activation of the Environ- mental Sciences Group (ESG). This Group has the responsi- bility to investigate the applicability of satellite observations to hydrology and oceanography within ESSA. The MLCs had their second major reorganization on November 9, 1967. This reorgnization included the renaming and realining of the Institutes for Environmental Research (lER) into the Research Laboratories (RL). These Lab- oratories are comprised of 11 Laboratories, one Institute, and one Facility, with all units reporting to a single Director. The MLC reorganization of April 5, 1968, within the Weather Bureau (WB) initiated a restructuring of the Bureau's field forecasting offices, with complete implemen- tation occurring over a 5-year period. Once implemented, approximately 50 Weather Bureau Forecast Offices (WBFO) will be created. These WBFOs will receive forecast infor- mation output directly from the National Meteorological Center (NMC), the National Hurricane Center (NHC), and the National Severe Storms Forecast Center (NSSFC). The establishment of the Office of Systems Development (OSD) within the Coast and Geodetic Survey (C&GS) on April 11, 1968, was the fourth MLC reorganization. This Office has the responsibility to design and develop systems which cross major C&GS program boundaries. Selected Service Program Highlights During this FY 68 and FY 69 reporting period, the various MLCs of ESSA significantly improved their service programs. Although additional information on programs covered generally in this chapter are found in Chapters 4 through 9, several programs are reported in detail only in this chapter. Selected highlights of these service pro- grams follow for each MLC. Weather Bureau In response to a need accentuated by the worst flooding (August 1967) in the history of Fairbanks, Alaska, the Weather Bureau (WB) installed a telemetry system in FY 68 for the State of Alaska. The Bureau coordinated its effort with the Corps of Engineers and the Geological Sur- vey. The system transmits hydrological information neces- sary to the preparation of flood warnings, using a specially designed radio network and associated telephone line-links to offices in Anchorage and Fairbanks where such infor- mation is collected and analyzed and where required warn- ings are issued. The WB is continually improving its weather forecast techniques. During the past 2 years, an automated pro- cedure for forecasting of maximum and minimum tem- peratures at the earth's surface was inaugurated at 131 cities in the country. Since September 1968, the NMC has transmitted these forecasts by teletypewriter twice daily di- rectly from the computer to these cities. To ensure more effective use of both radiosonde and rocketsonde data, better methods were developed for the construction of synoptic weather charts at high levels from 50,000 to 180,000 feet. High-level synoptic weather charts permit observers to follow the course of major stratospheric warmings which occur in the winter, to facilitate the re- search of stratosphere-troposphere interaction, and to im- prove the forecasting techniques at these high levels. These charts will be of value to the navigation of supersonic trans- ports (SST) and are important to the determination of tra- jectories for experimental constant-level balloons and for reentries of space vehicles. Another forecasting technique developed and tested suc- cessfully was a small-scale numerical model which permits forecasts of precipitation and surface winds in the eastern two-thirds of the conterminous States more rapidly than previously available computer guides. This subsynoptic ad- vection model (SAM), placed in operation during FY 68, produces automated predictions and transmits them by tele- typewriter twice a day for 79 cities. The Systems Development Office (SDO) of the WB de- veloped an analytical model for analyzing the performance of automatic weather-telephone briefing systems. This model will help overcome problems associated with the implemen- tation of automatic weather-telephone systems. Classical multichannel queing theory was applied during model de- velopment to correlate relationships among service time (or message length), demand rate, available channel, and performance (probability of a busy signal). Testing was successfully accomplished on an operational three-dimensional trajectory model developed by SDO. This model uses computer techniques to generate three-dimen- sional air trajectories from wind predictions produced by the six-level primitive equation (PE) model. Computerized 24-hour forecasts are produced from three trajectories and are then transmitted twice a day on the facsimile circuit from the NMC. Forecasts are displayed on a four-panel chart. Three panels consist of surface, 850-millibar, and 700-millibar temperature and dew point forecasts; the fourth panel contains 700-millibar relative humidity fore- casts and 12-hour net vertical displacements of air parcels ending at 700 millibars. Computer forecasts are prepared by the NSSFC to improve tornado and severe local storms forecasts. Coast and Geodetic Survey The geodesy and photogrammetry projects of the Coast and Geodetic Survey (C&GS) involve studies ranging from crustal movements to geodetic satellite triangulation. Twenty- two special survey configuration sites across known faults of the San Andreas System of California were resurveyed to study crustal movement. Where feasible, the time term in each of the coordinates and elevations evolved from the repeat surveys was used to modify the collected data. Determination of such a time-varying model, from which rates of strain accumulation and other geophysical quan- tities can be computed over the entire area, may eventually be used to predict earthquakes. Special releveling surveys were made in areas of sub- sidence such as the San Joaquin Valley of California. Major emphasis was placed on cooperative projects requested by many States and cities for urban geodetic control networks. A cooperative agreement between the Department of Commerce (DOC) and the Department of Defense (DOD) enables the C&GS to provide technical direction and give considerable support to the worldwide geometric satellite triangulation program. Currently 16 BC^ camera systems are available for the program, with the C&GS operating eight, assigning personnel to four, and having responsibility for the maintenance of all systems. ESSA, through its C&GS component, formulates the plans whereby ESSA can fulfill its responsibility for coordinating all Federal geo- detic control survey functions. In cooperation with the Geological Survey, the C&GS uses a recently developed system of computer-based tech- niques for analytical aerotriangulation to achieve results well within the established criteria for mapping control. Through additional planning and coordination of required mapping functions, this procedure can be as economical and efficient as geodetic methods for establishing mapping control. The completion of the Worldwide Network of Standard Seismograph Stations was a major advance in seismology. This 115-station system is equipped with identical sets of ultrasensitive seismographs and related instrumentation to locate seismic activity more precisely. Records from this Network are gathered by and made into permanent files at the National Geophysical Data Center in Asheville, N.C. Many new municipal ordinances require the placement of strong-motion instrumentation in tall buildings and earth- quake-prone areas. To meet these requirements, the Seis- mological Field Survey of the C&GS has increased the size of its instrumentation network to 349 strong-motion sta- tions and 368 seismoscopes by the end of reporting period. The record number of strong-motion seismograms obtained from the Imperial Valley of California earthquake of April 4, 1968, demonstrated the increased effectiveness of this expanded service. Investigation of the November 9, 1968, earthquake in southern Illinois gave further evidence that local ground conditions have a pronounced influence on the intensity of shaking and demonstrated that continued research may improve methods for forecasting the effects of future and even more severe earthquakes. In accordance with a long- established C&GS policy, isoseismal maps are prepared fol- lowing significant U.S. earthquakes; these maps have direct application in relating physical and environmental factors to industrial and urban development. Successful results have been achieved with programs written for automated computation of geodetic bearings and distances, position determinations, and spherical tri- angulation determinations. Computer programs were pre- pared to complete the symbols dictionary portion of an automated cartographic process now under study. An 18- month contract was initiated to determine the feasibility of a computer-based system for automating the carto- graphic process. National Environmental Satellite Center The most successful achievement of the National En- vironmental Satellite Center (NESC) in environmental sat- ellites during the past 2 years was the unqualified success of the Satellite Infrared Spectrometer (SIRS) experiment on NASA's Nimbus 3 satellite. The SIRS, developed by NESC during a 10-year period and launched by NASA in April 1969, provides vertical temperature profiles along the satellite subtrack. The experiment involves use of radiance from seven channels clustered around the 15-micron carbon dioxide absorption region of the spectrum. Temperature profiles and geopotential heights of pressure surfaces are obtained on a global basis from approximately 100,000 feet downward to the surface of the earth in those regions hav- ing clear sky conditions and to cloud tops in those regions having cloudy sky conditions. Data processing conditions have been developed to derive temperatures and geopoten- tial heights whenever the 120- by 120-nautical-mile field of view of SIRS is restricted by partly cloudy sky condi- tions; however, a number of problems remain. The NESC reduces SIRS data and provides them to the NMC for routine use in operational numerical analysis and predic- tion activities. Approximately 400 Northern Hemisphere SIRS soundings were available through June 1969 on a daily basis for use in the operational numerical analysis programs of the NMC. These SIRS soundings provide data over oceans or in sparsely populated regions where it is either impossible or impractical to use ground-based in- struments. The NESC reported that picture sequences from Appli- cations Technology Satellites (ATS), used to measure cloud movements and related wind activity, yielded information in the following specific areas: (1) Tropical air masses in long narrow jets that surge into the United States from the eastern Pacific tropics ap- pear to accompany many U.S. tornadoes. The relationship Launch of ESSA 9 spacecraft, February 26, 1969. A mosaic map, produced from ESS A 9 spacecraft photographs taken at 0030 GMT on April 22, 1969, showing a strong extratropical cyclone system over the North Pacific Ocean. of these jet streams to severe storms will be studied as more data are gathered. (2) Tropical hurricanes, the most destructive of storms that strike the United States, are also being investigated through ATS pictures made at 15-minute intervals. These pictures reveal changes in the structure of the spiral bands and the eye wall — ^the main energy region — which may be useful in efforts to modify these storms. A high correlation has been observed between the aver- age relative humidity present in the layer from the surface to 500 millibars and the amount, type, and pattern of clouds seen in satellite pictures. Based on this correlation, estimates of relative humidity throughout this layer are made from satellite pictures taken daily over the eastern North Pacific. These data are used daily at the NMC as additional input for the numerical weather analysis. De- tailed humidity patterns, derived from satellite data ob- taitied over the Pacific Ocean west of North America and over the Gulf of Mexico, are expected to improve precipita- tion forecasts for the United States. As ATS pictures become available regularly, these humidity estimates will be made over an area expanded to include all of the eastern North Pacific Ocean east of longitude 160° E. During the winter and early spring seasons, data from the Environmental Survey Satellite (ESSA) spacecraft are used to provide information on the boundaries of snow- fields and on the distribution of ice on the Great Lakes. Digited mosaics and pictures of snowfields are prepared daily for use in making flood potential estimates by River Forecast Centers (RFC) at Hartford, Conn., Kansas City, Mo., Portland, Oreg., Sacramento, Calif., and Salt Lake City, Utah. Charts showing ice conditions on the Great Lakes are also prepared and transmitted by facsimile for use by WBFOs at Cleveland, Ohio, and Detroit, Mich. The satellite pictures, and the charts and mosaics derived from them, provide the flood forecaster with a means, formerly unavailable, for maintaining current information on the areal extent of the snow cover. This information permits more accurate estimates of the water equivalent, and thus the flooding potential of the snowpack. The mapping of snow cover by complete mosaicking of satellite photographs was expanded to include Antarctic and Arctic regions in appropriate seasons. During the last 2 years, the NESC launched three space- craft (ESSA 7, 8, and 9) to maintain the National Oper- ational Meteorological Satellite System (NOMSS) estab- lished in February 1966. These spacecraft are furnishing Artist's conception and actual model of the TIROS-M meteorological spacecraft. Diagram courtesy of RCA Defense Electronics Products and photo courtesy of NASA. worldwide pictorial coverage of the earth and its cloud systems daily, except in areas of polar night. The TIROS-M (Television Infrared Observation Satel- lite), an operational prototype of the ITOS (Improved TI- ROS Operational Satellite) series, will add a nighttime cloud surveillance and day-and-night temperature mapping capa- bility by means of a scanning radiometer. This prototype will combine functions now performed separately by two ESSA spacecraft, with a consequent cost savings resulting from fewer launches each year. The first launching is sched- uled for January 1970. Environmental Data Service The Environmental Data Service (EDS), ESSA's archival arm, established an Agricultural Climatology Service Office (ACSO) in the Department of Agriculture (DOA) in Feb- ruary 1968. This new Office facilitates the real-time input of analyses of climatological data into decisions, operations, and policies of the DOA. The EDS developed and tested a technique for using satellite data to provide climatological information about the total cloud cover. Variations in monthly averages of cloud amount, computed from data derived from the tropi- cal Pacific Ocean, have a high correlation with changes in sea-surface temperature. These variations indicate the im- portance of sensible heat energy flux in the monthly aver- aged tropical circulation. In addition, the latitudinal gradi- ent of biweekly averaged cloud top height, derived from satellite infrared data, was used to compute estimates of diabatic heat energy involved with the Hadley circulation in the eastern Pacific tropics. In May 1968, the first Environmental Data Processing System, managed jointly by the DOC (ESSA) and the DOD (Air Force), was dedicated. This new System complex, replacing separate computer systems, has about three times more capacity than the combined predecessor systems. The new complex is operated by EDS's National Weather Rec- ords Center (NWRC) and by the Air Force's Environmen- tal Technical Applications Center (ETAC) through its Data Processing Division. Research Laboratories The Research Laboratories (RL) of ESSA operate sev- eral service programs in telecommunications, space dis- turbances, aeronomy and space data, and propagation con- ditions. In July 1968, the Telecommunications Disturbance Fore- cast Center, operated for many years at Fort Belvoir, Va., by ESSA and its predecessors, was replaced by a real-time system which uses a timesharing computer to forecast the probability, time of occurrence, and duration and magni- tude of shortwave fadeouts, polar cap absorption events, and magnetic storms and their effects on telecommunication systems. The new RL service, based in Boulder, Colo., permits users throughout the country to query the com- puter directly. The forecasting process utilizes solar, geo- physical, ionospheric, and communication data from many sources. These data are then evaluated, placed in operating data files within the computer, and used to provide the communicator with relevant information and competent ad- vice at any time. The completion of the Global Solar Flare Patrol Network during the reporting period was an important service ac- complishment in space disturbances. A new computer, in- stalled at the Space Disturbance Forecast Center in Boulder to complement the Space Disturbances Monitoring Facility computer in Anchorage, automatically handled the analysis and transmission of solar activity data and warnings. Solar flare forecasts and warnings of routine and special nature were provided to some 70 primary users by teletypewriter or direct telephone line. Improved computerized techniques were developed to predict solar events for telecommunica- tion and space programs and to provide procedures for predicting radiation at SST altitudes. A Forecast Procedures and Techniques Manual was published. For aeronomy and space data, service programs provide data on ionospheric and tropospheric propagation, solar activity, airglow, aurora, and cosmic rays to support na- tional and international needs. Approximately 1,500 re- quests for data — in the form of paper copies, microfilm, punched cards, magnetic tapes, and publication — are han- dled by the Aeronomy and Space Data Center each year; dis- tribution of these data is made to other Federal agencies, universities, commercial laboratories, foreign institutions, and individuals. Expansion of automated systems for ar- chival, retrieval, and publication of data continued. The responsibility for the Cornell University Visual Aurora Center was transferred to the Aeronomy and Space Data Center on July 1, 1968. Currently, all upper atmospheric geophysical disciplines except geomagnetism are now lo- cated in the Aeronomy and Space Data Center. Service programs involving ionospheric predictions and data are prepared and disseminated for military, scien- tific, and engineering applications. A direct-access, time- sharing computer has been introduced that is capable of providing forecasts of solar-geophysical disturbances which affect communications, surveillance, and the manned space effort. Tropospheric propagation predictions involve the development of physical and mathematical models for pre- dicting the performance of tropospheric telecommunications. Selected Research and Development Program Highlights The research and development (R&D) programs of ESSA during the reporting period are categorized by disciplines or by project name. Additional information on programs mentioned briefly in this chapter are discussed more fully in Chapters 4 through 9, but some significant programs are reported in detail only in this chapter. Selected highlights of these R&D programs are presented below. BOMEX Project One of the most significant R&D efforts involving ESSA during the past 2 years was the Barbados Oceanographic and Meteorological Experiment (BOMEX). A bilateral agreement, signed on July 9, 1968, between the U.S. Gov- ernment and the Government of Barbados inaugurated this international experiment. The BOMEX project is a major contribution of the United States to the World Meteorological Organization's (WMO) World Weather Program. Management of BOMEX was assigned to ESSA's Office of World Weather Systems. The project, recommended in the 1962 National Academy of Sciences (NAS) /National Research Council (NRC) Report on the Interaction Between the Atmosphere and the Ocean, Publication #983, was the first cooperative experi- ment in support of the international Global Atmospheric Research Program (GARP). This Report pointed out that a physical understanding of the processes of sea-air inter- action is important because the atmosphere and the oceans, constituting the fluid portions of the earth, interact as one mechanical and thermodynamic system. Initial planning for the BOMEX project was accom- plished by the Joint Air/Sea Interaction Panel of the Inter- agency Committee on Oceanography and the Interdepart- mental Committee on Atmospheric Sciences of the Federal Council on Science and Technology (FCST). The scientific and practical significance of BOMEX is that an extension of the numerical forecast period beyond a few days must take into account the atmospheric energy sources to compensate for the known decay of atmospheric motions by friction. BOMEX was designed to obtain quantitative information on the energy sources and sinks over the tropics where much of the energy received by the earth in the WATER SAMPLES (Be 7) T- TEMPERATURE H- HUMIDITY P- PRESSURE Wv-WIND VELOCITY S- SALINITY THERMOCLINE The BOMEX observation system. form of shortwave solar radiation is stored in the upper layers of tropical oceans. The energy transfer at the sea- air interface to the atmospheric boundary layer in the tradewind zone was observed as part of the BOMEX sea- air interaction program, and the transfer of energy to the upper layers of the atmosphere was observed during the BOMEX tropical convection program. These two major experimental programs and other BOMEX scientific pro- grams were highly successful in collecting the quantity and quality of observational data required. The implementation of this national scientific effort was led by ESSA within the DOC, and included personnel from the DOD, Department of the Interior, Department of Trans- portation (DOT), Atomic Energy Commission (AEC), the NAS, National Aeronautics and Space Administration (NASA), National Center for Atmospheric Research (NCAR), and the National Science Foundation (NSF). The basic objectives of BOMEX are summarized in the phrase, "the joint behavior and interactions of the atmosphere-ocean system in subtropical and tropical waters." ■MMMMB SATELLITE TRANSMIT-RECEIVE !■■■■■■■ NASA SCAMA ■■•■■•■■ LEASE LINE • ..•*... HP TELETYPE (BULK LINE) IT. & VOICE HP/VHP HP/UHP VOICE BARBADOS RAINIER SAT-TERM T.T. (HP) TELETYPE (HP) VOICE (HP) VOICE (HP) VOICE. 1- ,,.*• (HP) TUG MT. MITCHELL T.T. (HP) VOICE (HP) The BOMEX communications network. The experiment, which began May 1 and concluded July 28, 1969, was conducted in a 90,000-square mile area east of Barbados. Twelve vessels, 28 aircraft, and 1,500 scien- tists, technicians, and crew members from seven Govern- ment departments and independent agencies, 20 univer- sities, and 12 private research activities participated in the experiment. The project was divided into four phases, each ranging from 15 to 19 days, during which the most in- tensive sampling of the atmosphere and ocean ever at- tempted was performed. Nearly 100 independent research projects were attempted. Over 2,400 upper air soundings, 1,400 ocean probes to depths of 1,000 meters, and more than 500 aircraft missions were planned. Thousands of observations were made, using a variety of sensor systems and platforms including satellites. Extensive scientific in- vestigations were made of the sea-air interaction, tropical convection systems, radiation balance, oceanic circulation. and internal waves. These studies were initiated through the joint effort of Federal agencies, universities, and private laboratories and corporations. The processing and scientific analysis of the data were initiated immediately following the field phase. The Bar- bados Oceanographic and Meteorological Analysis Project (BOMAP) was established within the RL of ESSA for this task. Personnel in BOMAP work in cooperation with other participating Federal agencies and nongovernmental lab- oratories. A major contribution to BOMAP is the data processing support provided by the NASA's Mississippi Test Facility at Bay Saint Louis, Miss. Scientific review and coordination of BOMEX and BOMAP with the ob- jectives and planning activities of GARP have been ac- complished by an advisory panel of the NAS under its U.S. Committee for GARP. Data will eventually be archived at EDS's NWRC and at the National Oceanographic Data Center (NODC). Meteorology The various components in ESSA have made consider- able progress in several major R&D programs. In weather modification, for example, numerical models were devel- oped for: (1) the Great Lakes Program — ^to assess the potential of redistributing snow; (2) the Northeast Rain Augmentation Project — ^to study the physical feasibility of rainmaking from cyclonic storms; (3) the Florida Cumulus Seeding Program — to study the seeding potential for ice and condensation nuclei; and (4) the analysis phase of the Lightning Suppression Project — to study the electrical struc- ture of thunderstorms. The numerical models provide a better understanding of the physics of these phenomena. When these Programs and Projects enter the field test phase, the models will assist in the analysis. For weather forecasts and warnings research, the Na- tional Hurricane Research Laboratory (NHRL) has de- veloped an improved statistical technique for predicting hurricane movement. The results reveal a 15-percent reduc- tion in the average error for the 24-hour predicted posi- tion of the hurricane center. A numerical model, which simulates many features of the evolution and decay of hurricanes and provides a bet- ter understanding of the physics and energy processes of hurricanes, has also been developed. This model provides data useful for study and improvement of the design of field experiments. In addition, a numerical weather prediction model, de- veloped for testing during the 1969 hurricane season, gives promise for more reliable prediction of hurricane move- ment and intensity where sufficient data are available for making the computations. In weather analyses and forecasts research, a numerical SAM has been developed and operationally tested. This Model gives short-range (up to 18 hours) hourly circula- tion and precipitation forecasts for the eastern one-half of the conterminous United States. Results over a 1-year period show that these forecasts are superior to other numerical guidance available for the same period. Sophisticated mathematical models of the atmosphere and ocean circulations were developed and employed in a num- ber of important numerical experiments during FY 69, namely: (1) Simulation of the January-February global climate was successful in accounting for the global rainfall dis- tribution in defining the world desert patterns, delimiting the main river runoff basins, and predicting the location of spawning tropical cyclones. The key role of high and ex- tensive mountain chains was reaffirmed. (2) Extended prediction experiments were performed throughout the Southern Hemisphere and the tropics. These experiments indicate that the theoretical limit of atmos- pheric predictability to be at least 3 weeks and that several parameters previously thought essential for an initial de- scription of the state of the atmosphere may be redundant. Also, the significance of large-scale sea-surface temperature anomalies on midlatitude circulation and of interhemi- spheric atmospheric coupling for forecast spans between 1 and 2 weeks was established. (3) Definitive studies were completed on the atmospheric kinetic energy spectrum, derived from 10 years of data, and on the water balance over North America, the Gulf of Mexico, and the Caribbean Sea for a 5-year period. (4) A generalized oceanic circulation model for basins with irregular bottom topography and side boundaries was completed. Calculations from this model, applied to a study of the circulation of the Indian Ocean, gave an excellent prediction of the variations of the ocean currents with the changing monsoons. An analytical study of the Gulf Stream explained many observed features of its meandering flow. (5) Several extensive numerical simulations of thermal convection were performed, giving theoretical explanations for previously unexplained discrepancies between experi- mental and theoretical results. Additionally, equations for 2-, 3-, 5-, 8-, and 12-hour predictions of cloud ceiling and visibility based on simpli- fied surface weather parameters were developed and tested at selected major air terminals. Encouraging progress has been made in developing specialized techniques for pre- dicting such rare events as very low ceilings which close an airport and in applying nonlinear models of physical and kinematic factors for improving ceiling and visibility forecasts. The NMC's extended forecasts of the daily surface cir- culation during FY 69 has shown significant skill above persistence and chance to day 6 from the day of forecast. A series of experimental tests on every third forecast showed that use of long runs of the NMC 6-level PE numerical fore- casting model should result in further improvement; the model is used to prepare special forecasts such as for na- tional holidays, for space flights, and for springtime flood situations in the Mississippi Valley. The WB scientists developed a method for tracking the earth-coordinate positions of meteorological sounding bal- loons by means of radio navigation aids (NAVAID) such as Loran-C — long range aid to navigation — and Omega. Preliminary results of feasibility experiments using Loran-C signals have demonstrated that upper air wind speed and direction can be measured with greater accuracy than by conventional means. Because this method does not require stabilization and precise position accuracy of the ground station antenna, it has potential use aboard moving ships. To design and develop the next generation upper air observing measurement system, the SDO of the WB con- ducted an engineering study of atmospheric measurements and equipment. The objective was to provide functional specifications for which the required equipment would be developed. Many potential techniques, including satellite- borne sensors and ground-based indirect sensing, were iden- tified and studied. A trade-off analysis revealed that a bal- loon-borne instrument package, using a NAVAID approach — Loran-C and Omega — for wind finding, was the most 10 cost-effective system for upper air observing measurements. After a critical review by the WB, this approach was unani- mously accepted as "the next generation upper air observ- ing system"; the SDO has been directed to proceed with its development. The first prototype of an intermediate Automatic Meteor- ological Observing Station (AMOS) III-70 was completed and transferred to the WB's Test and Evaluation Laboratory (T&EL) for final tests. This Station will be a highly re- liable and extremely flexible device, fabricated almost com- pletely with integrated microelectronic circuits and designed to report such weather parameters as temperature, wind, pressure, and precipitation on long-line teletypewriter cir- cuits. Efforts in severe storm modification research have led to studies that give a better understanding of the life history of an individual storm, including such characteristics as the air flow through the storm, the development of the radar echo, and the hail and lightning associated with the storm. The feasibility of using airborne infrared techniques for the detection and quantitative analysis of hailstreaks has been established. A numerical method has been developed to analyze the electrical charge distribution in thunder- storms from aircraft measurements of the electrical field at cloud base. Stereophotogrammetric techniques have been developed for the quantitative study of cloud growth for possible future application to hail modification experiments. In tropical cloud modification, field seeding experiment results compare closely with the numerical simulation of the seeding effect and reveal that massive seeding of a par- ticular class of tropical cumulus causes more cloud develop- ment. Measurements from calibrated radar show that seed- ing has a significant influence on precipitation. The first field seeding experiment directed toward the modification of Great Lakes snowstorms was accomplished in November and December 1968. Although the weather pattern during this period produced only two opportunities for testing the basic hypothesis, much information and ex- perience were obtained about the mesoscale cloud systems over the Lakes, particularly in relation to: (1) target areas for seeding; (2) diffusion of the seeding agent and effect following airborne seeding at cloud base; and (3) radar analysis of artificial snow showers. Hydrology For river and flood forecasts and warnings, a cooperative research program was conducted at Danville, Vt., during the reporting period with the DOA's Agricultural Research Service. The objectives were to develop improved methods for measuring the water equivalent of the snowpack and techniques for computing the rate of snowmelt from meteor- ological factors. Substantial progress was made in correlating the in- tensity of radar echoes with thunderstorm rainfall and in devising a method whereby a small number of real-time rain gage measurements can be used to check or calibrate the radar depiction of precipitation over a large area. Development of a prototype flash-flood warning device was completed and given field tests and evaluation by the WB. Seismology Seismological research was conducted in three broad categories: engineering seismology, seismic wave travel times and earth structure, and tsunami generation. Engi- neering seismology research included studies of seismicity and earthquake probability, amplification of seismic waves passing through low-density materials, and earth tilt in tectonically active areas. Seismic wave travel times through the earth structure — crust, mantle, and core — have been studied. Tsunami-generation studies have been directed toward identifying parameters of earthquakes associated with tsunamis. Research in engineering seismology seeks to use knowl- edge of earthquake frequency and resulting damage to provide earthquake-resistance design criteria and seismic factors for both the private and public sectors of the econ- omy. Through a reimbursable agreement, initially con- tracted in June 1966 with ESSA, the Department of Hous- ing and Urban Development (HUD) provides a large por- tion of funds necessary for studying seismicity and earth- quake probability. In response to HUD's request for earth- quake loss data, a new technique was developed to estimate probable losses to dwellings in California resulting from (1) a maximum credible earthquake, and (2) a series of earthquakes likely to occur in California during a 100-year period. The results of a study involving the new technique indicate that dwelling losses would amount to approxi- mately $1.2 billion if a great earthquake occurred in the San Francisco area, and that dwelling losses in California over a 100-year period from earthquake damage would total about 16.5 billion. The method developed for the estimation of dwelling losses in California is very general, and could be applied as a method to compute losses to structures other than dwellings and in areas other than California. Another part of the HUD study has been the organiza- tion of all useful historical seismicity data for the United States to achieve rapid retrieval for statistical and other seismic studies. This seismic data consisting of data from 1938 to 1966 for approximately 28.000 earthquakes is listed on punched cards and magnetic tapes. A major development during 1969 was the release of an interim seismic risk map for the conterminous States. The map indicates the maximum level of earthquake intensity likely to be experienced in any geographic area. In the paper that accompanies the map, tables are given which permit the estimation of the approximate frequency of oc- currence of various levels of earthquake intensity through- out the country. A system has also been developed which will highly automate the collection of earthquake intensity data through- out the United States. This new highly automated system will result in better coverage and reporting of earthquake damage, and will speed the dissemination of reports giving intensity data collected throughout the country. 11 An important area of study in engineering seismology is the response of surficial geology and soils to earthquake- induced vibrations. Structural damage resulting from vi- brations is commonly more severe in buildings located on poorly consolidated or water-saturated materials than on hard rock. One of the prime goals of engineering seismology is to evaluate the potential hazard that vibration damage causes to various types of foundation materials. The C&GS approach generally has been to record data from both small earthquakes and microseisms simultaneously on various foundation materials, compute the Fourier amplitude spec- trum of each seismogram, and then compare the spectra. The technique of using "microtremor" measurements has been adapted by the C&GS from the Japanese. The preliminary field investigation by the C&GS of the Venezuelan earthquake of July 29, 1967, strongly sug- gested that a close relationship exists between severe earth- quake-induced building damage and certain kinds of surfi- cial geology in the Caracas Valley. Through a reimbursable agreement with the AEC, a study was initiated to examine the relationship between damage patterns and the under- lying soil and rock types in Caracas. The initial field meas- urement portion of the study consisted of seismic measure- ments of small earthquakes and background noise through- out the Caracas Valley. Relative amplitudes of seismic waves recorded at various locations throughout the Valley were then compared with the physical parameters of soils and rock formation at each measurement site. Studies of seismic wave travel times and the earth's inner structure have led to corrections for P (primary or com- pression wave) and 5 (secondary or shear wave) travel times, using data derived from 31 deep-focus shocks near Japan. Corrections were made to the Jeffreys-Bullen surface travel time tables, with acceptable small standard errors, at 10 distances from the epicenter. The tables will be fur- ther refined by adding station corrections. These new travel time tables will be the standard for the next several years. Observations of such identifiable events as fault creep, un- der investigation at a number of sites on the San Andreas and Hayward Faults in California, reveal that these events do not occur simultaneously at points tens of kilometers apart, but that conditions cause the creep to propagate along the fault at very low speeds. These observation results bear directly on the search for methods of earthquake prediction. Earth strains in the vicinity of a large underground nuclear explosion were successfully measured to evaluate the possibility that a nuclear blast could trigger a large earthquake at some distance from the explosion. Steplike residual strains were reported after a nuclear blast and agree with those reported for earthquakes of the same mag- nitude. Earthquake strain steps do not decay within several days, if at all, but such strain steps from a nuclear ex- plosion apparently decay to near zero within one-half hour. This decay with time appears to reflect the pressure his- tory of the cavity, and may provide a way of distinguish- ing underground nuclear explosions from natural earth- quakes. First-motion studies of deep- and intermediate-depth earthquakes were investigated on a worldwide basis to study the distribution of stress within descending "plates" of earth's crust. (According to the plate theory, the earth's crust appears to be divided into six major plates which are moving with respect to each other.) Results show that plates of crust sink into the upper mantle as a result of forces exerted on the excess mass within the crust. Data on focal mechanisms, obtained from a regional study of the largest earthquakes occurring in western South America during the 7-year interval, 1962-68, indicate that the data are in overall agreement with an east-east northeast direc- tion of underthrust for the Pacific crustal plate beneath the continent of South America. Systematized isoseismal information from 55 earthquakes occurring between 1928 and 1967 and empirical formulas have been developed from these events to determine the radius of each grade of intensity for earthquakes of given maximum intensities. A program is currently underway to identify significant parameters of earthquakes that are related to the gener- ation of destructive tsunamis. Very crude relationships between tsunami wave height and earthquake magnitude, focal depth, and water depth in the earthquake epicentral region have been known for some time. Attempts are being made to improve these known relationships and to develop a relationship between the nature of earthquake focal mechanism and tsunami generation. The basic attempt is to identify particular types of focal mechanisms that result in tsunami generation. Current research emphasis is upon development of statistical criteria for the objective eval- uation of the reliability of the focal mechanism computed. Geodesy Large-scale operational computer programs for satellite orbit prediction support the C&GS geometric geodesy pro- gram. Other orbit programs are being developed for geo- detic and geophysical analysis of dynamical data. An analy- sis is underway of gravitational harmonics which have reso- nant effects on the Passive Geodetic Explorer Satellite (PAGEOS). An alternate representation of the earth's gravi- tational field, using surface layers of variable density instead of spherical harmonics, is being investigated. Mathematical Geodesy, a major treatise by the late Martin Hotine, completed during the reporting period, will be pub- lished in October 1969 as ESSA Monograph 2. This publi- cation updates the mathematical theory of geodesy based on the application of tensor calculus. Geomagnetism A reliable analytical method for deriving long-term sec- ular change in the strength and direction of the earth's magnetic field was developed for application upon U.S. and world magnetic charts compiled for issuance beginning in 1970. This new method eliminates handdrawn graphics 12 and results in complete automation through the use of elec- tronic computers and automatic plotters. The magnetic charts serve as the source of magnetic compass information in- cluded on all navigation charts. The C&GS model — a Fortran IV computer program — of an International Geomagnetic Reference Field (IGRF) con- tributed to the final IGRF adopted by the International As- sociation of Geomagnetism and Aeronomy (lAGA). The IGRF provides a universal reference field used by space scientists and by geophysical exploration groups as an ac- ceptable datum for delimiting magnetic anomalies result- ing from crustal and upper mantle structures. Examples have been found of magnetic events preceding by 1 day the occurrence of earth creep on the San Andreas Fault in California. Interpretation of this type of magnetic event may offer a means for predicting earthquakes. Trends in the earth's magnetic field offer clues to future developments. Should a field reversal develop, the shielding effect would be degraded, allowing greater penetration of solar radiation which may produce an adverse biological effect. To predict future magnetic developments, the Earth Sciences Laboratories (ESL) have analyzed one of the most recent field reversals and initiated the design and con- struction of required equipment to study such develop- ments. Spherical harmonic analyses were performed on the mag- netic field of the earth for epochs 1725, 1760, and 1800, giving secular change of the field during historic times. The addition of these results with other analyses of later epochs will improve knowledge of the fluid motions in the earth's core and their relation to changes in the earth's magnetic field, and will determine whether the earth's field is beginning to reverse. Paleomagnetic facilities are now available to study details of the last reversal for comparison with present trends. Charting Past research in aeronautical charting on color process printing has resulted in the elimination of one five-color press run for each visual aeronautical chart produced. Programs of research within marine description, map- ping, and charting have resulted in the development of an automated method for predicting sea and swell for both the North Atlantic and North Pacific Oceans up to 36 hours in advance. This method, based upon wind forecasts of the numerical prediction models, was given operational testing during the reporting period. Oceanography The modification processes which a relatively dry con- tinental air mass undergoes while moving over an ocean surface were investigated off the Virginia coast. Ships, teth- ered balloons, constant-level balloons, radar-tracking rawin- sondes, and oceanographic observations were used to define the air mass-water modification processes. An intensive in- vestigation of the developing southwestern monsoon moist layer was made from the Somali Coast of Africa to Bombay, India, utilizing level-tethered soundings. Boundary Layer Instrument Package (BLIP) radiosondes, salinity-temper- ature-depth (STD) recorders in position. Expendable Bathy- thermographs (XBT), and ATS satellite data. These field projects in sea-air interaction studies are providing pre- liminary information on exchange processes before a large- scale intensive study of the area is made. The first operational test of a Tidal Current System (TICUS) of four to six buoys, each supporting subsurface current meters to measure speed and direction of tidal currents at three selective depths, was made during the tidal current survey of Long Island, N.Y. This new C&GS system complements the newly developed ODESSA (Ocean Data Environmental Science Services Acquisition) buoy system for measuring currents, salinity, and temperature in major bays, estuaries, and over the Continental Shelf. A novel data systems design was developed to provide an integrated approach so that Ocean Survey Vessels (OSV) can accomplish both required ship-operations and scientific data activities. This data systems design embraces data acquisition, verification, editing, processing, and display and makes possible handling of large volumes of data per unit of time. The systems design also enhances substantially the effectiveness of OSV to collect subsurface, bottom, and sub- bottom marine data required by the scientific community and industry. As part of a long-range Continental Shelf mapping pro- gram, portions of the northern Bering Sea floor were sur- veyed during the summer of 1968 by the USC&GS ships Surveyor and Oceanographer and during the summer of 1969 by the Surveyor. Data were collected on bathymetry, gravity, magnetism, sediments, currents, and tides for use in the preparation of maps showing bathymetry, gravity, and magnetism of the area. This survey and scientific inter- pretation of collected data are a cooperative effort of ESSA and Geological Survey scientists who are interested in the structure and composition of this large basin. A highly sophisticated model of the sea-air system was developed during the past 2 years. An analysis of two pre- liminary experiments indicated that important features of surface hydrology, such as the formation of a desert in the tropical rain belt, can be successfully simulated and applied to the study of climate evolution, to the development of very long-range predictions, and to the analysis of the effect of weather modifications. In March 1967, the LTSC&GS ship Oceanographer began its global expedition from Jacksonville, Fla. The ship visited Great Britain, Monaco, the Soviet Union, Ethiopia, India, Malaysia, Australia, New Zealand. Chile, and Peru before reaching Seattle. Wash., in December. During the various "legs" of its journey, the ship accommodated more than 150 marine scientists, the majority representing various countries in the world. The ship's scientists did consider- able research in physical oceanography, marine geology and geophysics, bathymetry, and sea-air interaction. 13 Telecommunications Several new telecommunications and space developments have taken place in millimeter-length wave propagation. These developments include a climatological method for pre- dicting radio absorption by clouds and precipitation and a method for estimating maximum thunderstorm absorption; both methods will be used in communication systems de- signs. Research in radio meteorology has led to (1) devel- opment of a combined optical-radio method for determining average water vapor content of air along a path and for averaging evaporation from the underlying surfaces, and (2) determination of meteorological factors causing ex- tended circuit outages along an obstacle diffraction path. A technique has been developed which allows for lab- oratory experimentation on the performance of high fre- quency (HF) radio channels by simulating the propagation characteristics and effects of atmospheric radio noise, per- mitting communication equipment tests in the laboratory, and minimizing the need for expensive field tests. In the field of optical wave propagation, a prototype two- color geodetic distance-measuring instrument has been de- veloped. Field testing has demonstrated a precision sur- passing any of the presently available commercial instru- ments and providing a greater potential for geodetic survey operation economies. A study confirmed the theory that very low frequency (VLF) energy, less than 1.5 MegaHertz, is transmitted along magnetic field lines at great heights. Because solar outburst events greatly attenuate VLF signals, a study was also made to calculate the effects of these events on VLF propagation. Both of these studies will aid in describing and predicting the propagation of VLF signals. Studies also have been conducted on the irregularities of the ionosphere and exosphere, using signals from satel- lites. These studies have permitted precise measurements of the electron density along the satellite path, and provided correlation of electron density peaks and troughs at high latitudes with other phenomena and ionization irregulari- ties from Explorer 20 and Alouette I and II satellite data. By using data from these two series of satellite flights, meas- urements of the mutual impedence between two electrodes can determine the electron density accurately. Laboratory measurements of the reaction rates among ionized and neutral constituents found in the upper at- mosphere have provided valuable basic physical data for understanding the behavior of ionization during space ve- hicle reentry. Other studies conducted provide strong evi- dence that the observed water cluster ions in the upper atmosphere cannot be entirely explained as rocket contami- nation, an implication important to understanding the chem- istry of the D-region of the ionosphere. In space disturbances forecasting research, a ground- based solar proton detection system and improved prediction techniques for solar flare and polar cap absorption events have been developed. Satellites NASA's ATS-1 and ATS-3 spacecraft, launched in De- cember 1966 and November 1967, respectively, each carry two experimental systems important to the development of ESSA's environmental satellite system. The first of these systems is the spin-scan cloud-camera (SSCC) system. The ATS-1 carries a SSCC capable of taking a large-area photo- graph over the earth every 24 minutes, or alternately every 15 minutes if only one-half of the image is desired. The ATS— 3 carries a similar SSCC system; initially this camera system had full color capability, but a failure of the red- sensitive channel reduced the effective imaging to black- and-white. The SSCC pictures have been used to study the development of the tropical storm systems and severe local storms. Techniques were developed for using the picture sequences to obtain realistic estimates of upper level v/inds, particularly over data sparse areas. The second experimental systen. carried on the ATS spacecraft involved the testing of several systems for col- lection, transmission, and retransmission of raw and proc- essed data. Automatic stage indicators were queried by the satellite at specified intervals, and their data were then acquired by the satellite and retransmitted through its Tran- sponder System to a central collection point. Processed satellite photographs, analyzed charts, and time signals were sent from originating ground stations for relay to remote- receiving stations. The success of these two experimental systems forms a firm basis for the development and deployment of the Geo- stationary Operational Environmental Satellite (GOES) sys- tem. The first prototype of the GOES spacecraft, NASA's Synchronous Meteorological Satellite (SMS), will be launched in 1972 according to current plans. The SIRS on board the Nimbus 3 satellite was developed, tested, and qualified by the NESC with the fiscal support of the NASA. The SIRS instrument was spectacularly suc- cessful and was still operational at the end of the reporting period. The SIRS represents a major scientific breakthrough of paramount importance to meteorology. It is now scien- tifically possible and economically feasible to obtain rou- tinely on a global basis quantitative values of the vertical profiles of temperature and corresponding geopotential heights of pressure surfaces vital to improved numerical analysis. Follow-on models of SIRS, incorporating a smaller field of view and scanning normal to the satellite subtrack to improve accuracy, to increase area coverage, and to enhance the probability of obtaining clear sky conditions, will be flown on future Nimbus spacecraft. The SIRS-B, an in- strument similar to the first SIRS but with added capa- bility for obtaining measurements of the vertical distri- bution of moisture in the atmosphere, will be tested aboard Nimbus D which is scheduled for launch during 1970. Two additional instruments are being designed to acquire ver- tical temperature and moisture profiles from satellites: the Infrared Temperature Profile Radiometer (ITPR) and the 14 Vertical Temperature Profile Radiometer (VTPR). The ITPR is intended to provide an improved capability for acquiring data over partly cloudy areas; the VTPR is de- signed as a relatively small instrument package for use on operational spacecraft beginning in 1972. An operational system which will also provide gross moisture profiles is planned for ESSA's ITOS spacecraft in 1972. Design has been completed and fabrication is about one- half completed on a television scan-display for analysis of ATS-derived cloud motions. A computer program has been written and checked to use outputs from this device. The principle of this scan-display system is (1) to assemble a picture sequence into a time-lapse display by electronic storage and display, and (2) to enable the operator to pro- duce punched paper tape data for a digital computer which will make maps of cloud motion. The purpose of the system is to automate procedures for deriving useful wind data from the ATS, and later from the GOES on a more accurate and timely basis. A program for estimating high-level tropical winds from cirrus plumes seen in satellite pictures is now in daily oper- ational use. These derived winds provide the primary source of data for the daily tropical analyses and forecasts pro- duced by numerical methods. With the inclusion of wind data from satellites, much improved analyses (and hence forecasts) are possible for the entire tropical and subtropical climatic belts. A better understanding and more effective surveillance of tropical weather events are valuable, not only for immediate use, but also for studying the relation- ship between tropical and midlatitude weather processes. There have been promising developments in the use of High Resolution Infrared Radiometer (HRIR) data from satellites to measure sea-surface temperature. Although the validity of some random detail apparent in the analyses must be checked, major features such as the west wall of the Gulf Stream are clearly defined. Preliminary results show that horizontal gradients of absolute temperature appear to be within usable limits of accuracy. Cloud pictures are required for the development of an objective method to derive constant pressure heights for numerical models of the atmosphere. Vertical motion is in- dicated by the presence or absence of clouds; this motion indicates vorticity — or the rate at which air spins with re- spect to the earth. To attain a corrected current forecast analysis, vorticity values are used as the basis for modifi- cations to the previous 12-hour forecast map contours. The current procedure, which is still under development, is pri- marily manual, but work is progressing toward a fully auto- mated technique. Developments of this kind hopefully will result in greatly improved analyses over oceans and other sparse data areas, and hence to improved forecasts. ORGANIZATION AND PROGRAM The mission responsibility of ESSA, broadly stated, cov- ers the description, study, and prediction of the physical environment. It is the responsibility of ESSA to collect and interpret environmental data, using such data to obtain a basic understanding of the nature and behavior of man's environment, to predict and give timely warnings of en- vironmental hazards, and to facilitate engineering decisions in building design and urban planning. ESSA also conducts R&D to achieve an understanding of the processes and phe- nomena of the physical environment and to improve the capability to discharge its mission. This mission is administered through eight substantive "service" activities subdivided into program elements for planning, programming, and budgeting. These service ac- tivities are fulfilled through ESSA's five Major Line Com- ponents (MLC) : the Weather Bureau (WB), Coast and Geodetic Survey (C&GS), Environmental Data Service (EDS), National Environmental Satellite Center (NESC), and Research Laboratories (RL). Organization During this reporting period ESSA made certain modifi- cations to its internal structure, although the basic organi- zational structure for the MLCs established in 1965 was retained. Five major organizational changes occurred within the ESSA program management structure, two within ESSA Headquarters and three within the MLCs — one each for the RL, WB, and C&GS. On September 8, 1967, the ESSA Headquarters organi- zational structure was modified to consolidate the Offices of Planning and Program Evaluation, Science and Engi- neering, and User Affairs into a single Office of Plans and Programs, headed by an Assistant Administrator. This Office is divided into three Divisions and one Group: Plans and Requirements Division, Programs Division, Program Evaluation Division, and User Affairs Group. This reor- ganization provides ESSA with a focal point to develop, implement, and maintain a program planning system to achieve ESSA's objectives. The Office has the responsibility to provide a continuing evaluation of ESSA programs and accomplishments, to give advice and guidance to the Ad- ministrator, and to initiate action on program aspects of resource allocations, retrenchments, and reprogramming. Personnel within this Office of Plans and Programs, in cooperation with ESSA line and staff organizations, develop a comprehensive 5-year program and compatible financial plan from which budgets can be formulated for the Ad- ministration. The Office is also responsible for a continuing coordination and evaluation of ESSA programs, accom- plishments, and user relations. The Administrator, Deputy Administrator, Associate Ad- ministrator, and Directors of each MLC provide many of the requirements and receive most of the resulting prod- ucts of the Office of Plans and Programs. Personnel from this Office work with members of the Office of the Assistant Administrator for Administration and Technical Services (ADTECH), particularly the Divisions of Budget, Finance, Management Systems, and Scientific Information and Docu- mentation. Similarly, there is direct and continuing inter- action with counterpart planning, programming, and sys- tems analysis staffs throughout ESSA, the Department of Commerce (DOC), and interagency groups or activities in- volving the Federal scientific and technical community. The second reorganization in ESSA Headquarters oc- curred within the ADTECH Office structure. On the effec- tive date, January 31, 1969, the Management and Organiza- tion Division and the Management Systems and Informa- tion Division were merged into a Management Systems Di- vision. This reorganization provides unified staff assistance to develop and improve management systems that ESSA's organizational elements require in program direction and planning. This new Division, cooperating with the Computer Di- vision of ADTECH, is responsible for the development of advanced administrative management and information sys- tems. Activities essentially involve a centralized automatic data processing (ADP) system which collects, processes, and disseminates information to managers on program I 15 B c^ -A. oosto t- UJ UJ i^g "=l UJ I*' UJ = Z oe o o I- I- «* ^ a < I- «* LU > UJ w» 1 < o z X u Lkl t- Q o Z < c = -o z °,o ra o E 5 b fc; O Q. ■■§ z 7 Q_ ej CO o < ^ K O 5 g (T >- g Q E 1- o ^ Z a> o £ o tS^ ^ E t- u S, 1— < U- nal Affa ormatio ffairs ither S O Li- <• rnati icin tion dW 1- ■s-e g 5 V) -E > LU -.1 Z 1- o ,/,-= 1x1 3 _i —1 i< o 1- < z «* 00 e/> °-S E S g tej O ;^ CD CO ^ «I c O o SJora^SaigJJ Si? O --^ SgO, : -a: CD z ^ CO «x J 2=" 2 ^sij; o I— o = Uji^Q^Q O} a> c c a> c C3 c_> C_3 LJ TO CTJ O Q CT3 CC CO o O k— 00 >^ n a> Q. o CO S CD >> F CTJ o c c o o ro Z ^ ersist over extended time periods may be caused by feed- jjack from underlying land or water surface, and to dis- cover the physical mechanisms and processes that could have helped form such persistence. (The GFDL is also mak- ing models and extensive computer studies of ocean-atmos- phere coupling.) The procedures used in this study con- sist of establishing and solving numerically two separate systems of equations which are designed to resemble in their principal features those equations that govern the behavior of the atmosphere. One system considered the feedback effects of the underlying surface; the other did not. Two separate systems of equations were formulated, and par- ticular solutions were obtained for periods extending a few weeks. Work is underway on extending solutions for periods of 6 to 12 months or longer to provide more con- clusive evidence of persistence. Numerical simulation of the seasonal variation of the thermal and dynamical structure of the troposphere-strat- osphere system was conducted by the GFDL, using the global general circulation model with the actual distribu- tion of mountains, oceans, continents, and the observed seasonal variations of sea-surface temperature. The influ- ences of seasonal fluctuations of solar insolation and the hydrologic components on the atmosphere circulation were of particular concern in the simulation. To resolve the synoptic scale disturbances of the tropics, a grid system with high resolution was chosen using a domain of limited longitudinal span. Major objectives of this numerical modeling experiment are to examine the role of convection in maintaining tropical disturbances and the Intertropical Convergence (ITC) Zone, and to investi- gate the interaction between the tropics and midlatitudes. Numerical simulation of the evolution and maintenance of water vapor and that of ozone in the stratosphere was also performed. For this study, an 18-level model with high vertical resolution was used. Mechanisms for the ex- change of various quantities (heat, momentum, water vapor, and ozone) between the stratosphere and troposphere were determined. The nature of dynamical-photochemical-radi- ative coupling in the model stratosphere was analyzed so that the degrees of freedom of the model were gradually increased. Because of the very long relaxation time of stratospheric circulation, investigations into economical methods for ap- proaching quasi-equilibrium in numerical simulation experi- ments were conducted. In addition, two general circulation experiments were run with a global model and without the effects of mountains. The comparison between the two ex- periments indicated the role of mountains in maintaining the general circulation of the atmosphere. The climatic state of the global circulation was represented by the zonal mean state of the atmosphere and by such statistical quantities as the amount of eddy kinetic energy, eddy transfer of heat, and angular momentum. These quantities are the integrated measures of the intensity and structure of individual synop- tic scale disturbances. The object of the investigations was to integrate the closed system of equations which express all the climatological quantities as time-dependent variables. Upper Atmosphere Investigations The NMC has conducted upper atmosphere investiga- tions whose primary objective is the study of the structure, circulation, and energetics of the stratosphere and neighbor- ing layers. Subordinate objectives were to apply the results to improve stratospheric map analysis, and to describe the variable atmospheric environment of supersonic aircraft and reentry vehicles. The investigation into these altitude re- gions is of increasing theoretical and practical importance to the mission of the WB. Objective analyses techniques were used to improve com- puter-analyzed 100- through 10-millibar charts and to pro- duce 5-, 2-, and 0.4-millibar charts from rocketsonde re- ports. These charts and vertical cross sections are utilized for continued study of the origin and nature of stratospheric warmings, for which the NMC serves as a World Warning Agency. The theoretical aspects of the investigations in- 33 I elude the description of the role of the stratospheric energy cycle in relation to available tropospheric energy. Detailed investigations into reporting irregularities and disparities between rocketsonde and rawinsonde reports have led to corrections to account for day-night temperature differences and characteristics of different instruments used. General Circulation of the Ocean-Atmosphere System To investigate the role of the ocean's circulation in main- taining the climate and that of the atmosphere in main- taining the dynamics of the ocean, a numerical simulation of the thermal and dynamical structure of a joint ocean- atmosphere system is underway by GFDL. Global general circulation models of the atmosphere and of the ocean, de- veloped separately, were combined for the simulation. Be- cause of the extremely long relaxation time of the deep oceanic circulation, efficient methods for approaching a quasi-equilibrium are in development. Numerical simula- tions were made for various idealized configurations of continent and ocean to provide an insight into the relation between climate and large continental landmasses. Simulations have been performed for the Indian Ocean, successfully predicting the striking changes in the Somali Current resulting from seasonal monsoon changes. For time variation studies of the structure of the joint system, sea- sonal variations of solar insulation were taken into consider- ation. Numerical simulation of the seasonal variation of the thermal structure, general circulation, and hydrologic cycle was the main objective of those studies. The quasi- equilibrium state, which is obtained for the annual mean insolation, was chosen as the initial condition for this numerical integration. By integrating the joint system for an extended period, a study of their time evolution for periods longer than 1 month or 1 year can be undertaken, and information on the long-range evolution of climate can be obtained. The NMC is also involved in studies that concentrate on the interrelationship between the atmosphere and oceans, particularly in the prediction of large-scale atmospheric evo- lution. The aim of one of these studies was to apply those physical principles governing the evolution of the atmos- phere and oceans to the prediction of sea temperature, storminess, and weather changes for periods of 1 month or longer. This project involved the study of the energy bal- ance of and energy exchange between the atmosphere, land, and oceans in relation to anomalies in ocean temperature, snow, and ice cover. Acquired knowledge was applied to physical models for numerically predicting the evolution of monthly mean states of the atmosphere and ocean. A study, concluded in FY 67, of the 1961-1966 North- eastern U.S. drought led to a more general study during the last 2 years of seasonal precipitation for States in this region in relation to patterns found in other States. New emphasis was placed on ocean-atmosphere interac- tions over the Pacific Ocean. Tests and evaluation on nu- merical models for predicting mean rainfall and temperature in the atmosphere and ocean for 1 month in advance were conducted. An improved numerical model which could in- corporate the mean water budget of the atmosphere, hori- zontal heat transfer in the atmosphere and ocean, and reflectivity of the earth's surface was developed. Basic Geophysical Fluid Dynamics A finite difference model of annulus circulation has been set up by GFDL to yield solutions to the three-dimensional Navier-Stokes equations in polar coordinates for laminar fluid flow. The fluid motion is driven by rotation and lat- eral temperature differential. The model was devised to describe and examine geophysical fluid modes in pure and isolated form, and at present is being used to analyze such basic annulus dynamical modes as vacillation. Because the model system is fufly three-dimensional (the hydrostatic assumption is not made), the system can be used to model other geophysical phenomena in which vertical motion is large. Such an application was made to study the genesis and evolution of frontal systems as a supplement to ana- lytical studies. Numerical experiments were run with and without a mean wind shear to simulate dry convection with height. Initial efforts were directed toward the simulation of laboratory experiments. Subsequent numerical experiments were di- rected toward simulation of convection in the earth's bound- ary layer. A primary goal in this study was to gain an understanding of the breakdown of laminar convection into turbulent convection with increasing Rayleigh number. In studies of thermal convection equilibrium with rotation, the fundamental processes in convection were analyzed, in- cluding the roles of Ekman layers, variable fluid parameters, and finite-amplitude effects between rigid boundaries in uniform rotation. The two-dimensional Boussinesq approximation was ap- plied to the steady Navier-Stokes equations, and the nu- merical simulation is quantitatively compared with analytic theory and high-precision laboratory data. Frontal dynamics were evaluated by studies of frontal genesis and instability through linear stability and analysis. The energetics involved were investigated by analytic and numerical techniques. The growth of surface water waves and the subsequent sea- air interaction when a turbulent shearing flow in the air passes over a body of water initially at rest were also being studied. The problem was treated numerically with the goal of ultimately attacking the nonlinear, finite-amplitude case. Observational Studies The GFDL conducted a series of observational experi- ments involving studies that used aerological data from May 1958 to April 1963. The atmospheric energy cycle for 10-degree-wide latitude belts between 10° S. and 90° N. and its annual variation were studied using 5 years of radiosonde data. The total energy was subdivided into its internal, latent, potential, and kinetic components. By cal- culating the vertically and zonally integrated convergence of each form of energy into these latitude belts by mean meridional and by transient and standing eddy circulation, GFDL scientists were able to determine (as a residue) the rate at which the actual energy conversions take place in 34 the atmosphere as a function of latitude and season. A water balance study determined the mean monthly values of vapor flux, vapor flux divergence, runoff, evapotranspiration, and combined surface and subsurface storage change over the North American continent and its major drainage areas. The vapor flux was partitioned into contributions from standing eddies, transient eddies, and mean meridional cir- culations. The characteristics and seasonal variations of the three modes of transfer were evaluated on a mean monthly basis. Observational Stations Work by the Equipment Development Laboratory (EDL) of the WB continued during the last 2 years on an inter- mediate automatic weather station, the AMOS (Automatic Meteorological Observing Station) III-70. This project is intended to develop an automated equipment complex to provide both manned and unmanned meteorological obser- vations. The AMOS III-70 frees the observer on duty for more complex tasks and also allows observations when no observer is present. The design of the AMOS III-70 per- mits modularity, high reliability, ease of maintenance, and miniaturization. The basic unit contains modules designed to report temperature, dew point, wind speed, wind direc- tion, altimeter setting, precipitation accumulation, and pre- cipitation occurrence. During FY 68, modifications to the grounding system be- tween the basic unit and sensors were completed and noise levels reduced. A sensor simulator was also fabricated and used to test the AMOS III-70 over a wide range of param- eters. Except for the precipitation occurrence sensor, the basic station successfully completed environmental testing in FY 69. The basic system was adjudged fully suitable from an engineering standpoint, and work was initiated to prepare specifications for operational procurement. Another phase of the AMOS III-70 project involved the development of the Manual Input Device to provide an ob- server with a way to add his observations of ceiling, visi- bility, weather obstructions to vision, and sea level pres- sure to the AMOS 111-70 message for transmission. In FY 70, two manual input prototypes, which allow data input from either a local or remote location, will be completed. A method now under development adds a "remarks" capa- bility to the Manual Input Device. Weather Sensors The EDL has maintained research on the development of components for surface observing systems, specifically im- proved weather sensors. The Laboratory has conducted re- search into the development of a set of basic sensors (pressure, temperature, dew point, and wind) which can operate unattended for long periods of time in remote locations where commercial power is not available. These sensors will be evaluated for use with a Remote Automatic Meteorological Observing Station (RAMOS). In FY 69, development work leading to a RAMOS included an analy- sis of commercially available amplifiers to determine their reliability, accuracy, and long-term stability. Particular em- phasis was placed on amplifiers with low-power consump- tion and good temperature reliability. With these ampli- fiers as basic building blocks, new sensors will be devel- oped to measure the basic meteorological parameters of temperature, dew point, pressure, and wind. In FY 70, an engineering model of an Electronic Altimeter Setting Indi- cator will be developed under contract. As part of sensor research, EDL conducted development work for an improved hygrothermometer. During FY 68, all circuitry for the aspirated hygrothermometer was de- signed and components received. Compatibility with the AMOS III-70 was accomplished with minor modifications to temperature and dew point boards. Work during FY 69 centered on exploratory development of a small package including thermometer, hygrometer, aspirator, pulse dura- tion modulation (PDM) output, and analog current output. Fabrication and assembly of an experimental model of an all-electronic lithium chloride hygrothermometer was com- pleted in FY 69. In a related eff^ort, EDL completed the development of special wind sensors and data processors that simplify and correctly measure and compute mean wind and wind fluc- tuations. This project included: (1) the design of dynam- ically correct rotating cups and vane; (2) the design of a wind vector component generator; and (3) the design of analog data processors to compute wind statistics. During FY 68, the first design of a transducer to convert directly from cup anemometer and vane motion to orthogonal com- ponents was completed and fabricated. The experimental cups and vane were developed in FY 69, along with a fre- quency analog transmitting-and-receiving indicating system. Meteorological Statistics Studies Research was conducted by the Air Resources Laboratory (ARL) of RL on the application of mathematical statistics to those atmospheric science problems concerned with the understanding, prediction, or ultimate control of the physi- cal processes of the atmosphere. During FY 68, research focused on the influence of the lunar-solar gravitational tide on various atmospheric phe- nomena, including tropical cloudiness, certain quasi-biennial oscillations, and general circulation. Considerable evidence was found for an apparent latitudinal adjustment in surface pressure — represented by the zonal index — in response to variations in the gravitational tides; the effort to develop and understand these relationships continued. Two solutions to statistical-meteorological problems of general interest were formulated: (1) a stepwise multiple regression procedure for obtaining predictors for a non- stationary time series; and (2) a new correlation statistic for testing the association between two time series, each containing serial correlation. In FY 69, research continued on the tidal relationships to sea level pressure distribution, with new studies under- way on the diurnal variation in types and amounts of tropi- cal clouds within the tidal framework, on the relationship between coastal rainfall and general circulation features, and on a scheme for long-range forecast of rainfall at a single 35 station based on certain surface features for dates sug- gested by tidal relationships. As needs arose, cloud seed- ing experiments were designed and analyzed. Upper Air Systems The SDO over the last 2 years has conducted several efforts aimed at automating data processing associated with upper air observations. Through its TDL, formulas and procedures were derived for use in computers in place of human data processors. During FY 68, considerable effort was devoted to developing special procedures for use when input data were missing or doubtful. In FY 69, TDL de- vised specific computer procedures for the numerical cal- culation of precipitable water, a parameter used in making quantitative precipitation forecasts. The EDL also conducted development work aimed at semiautomating computations of rawinsonde data to reduce human error and manpower requirements. A radiotheodolite angle/range digitizer was designed and developed to accept raw analog data from the standard WB radiotheodolite witid-tracking equipment and to convert it to a digital form, using the Baudot code for teletypewriter transmission. The angle/range digitizer is currently undergoing test and eval- uation; preliminary results are very encouraging. To take advantage of commercially available time-sharing computers, a major design change is being made in the digitizer to produce output data in ASC II code — ^the standard code employed by such systems. Another related effort conducted by EDL in FY 69 is aimed at taking advantage of locally available time-sharing computers to make calculations that have traditionally been done manually by two men. Accordingly, rawinsonde com- putational and error-checking programs were developed that employ a conversational mode for input. This method en- ables the computer to query the observer when questionable data have been entered. The system is designed so that the observer still encodes the messages for transmission, during which time he can also check on the reasonableness of the computer's output. The system developed requires only one man to take an upper air observation. Operational tests were conducted in early 1969 at J. F. Kennedy Inter- national Airport's upper air station; minor adjustments to the procedures were made as a result of the tests. The WB is now implementing this technique on an operational basis at a number of upper air stations. In a major contribution toward development of the next generation upper air data acquisition system, the Systems, Plans, and Design Division (SPDD) of SDO completed a Systems Engineering Study of Atmospheric Measurements and Equipment (SESAME). Systems concepts and func- tional equipment specifications were derived for the acqui- sition system which will be designed to provide macroscale, mesoscale, and near-microscale upper air data. The SESAME project involved a comprehensive survey and forecast of potential upper air measuring techniques, including satellite-borne and ground-based indirect sensors. The results of this survey showed that only balloon-borne instruments would meet the data requirements for all scales of motion during the 1970's. An objective cost effectiveness model — a linear polynomial with variable weights — was developed to compare competing upper air systems. A trade- off analysis was made using the cost effectiveness model on a number of wind-finding techniques such as radio distance finding, navigational aids (NAVAID), and radar. The re- sultant analysis showed that a balloon-borne package using a NAVAID approach — long range aid to navigation (Loran- C) and Omega — for wind finding was the most cost effec- tive system for upper air measurements in the 1970's. The development work by T&EL on the next generation upper air system involved testing and evaluating an Electro- lytic Hydrogen Generator for use in inflating upper air balloons. A 9-month test period, completed in FY 69, showed that this Generator is capable of producing sufficient hy- drogen to meet the needs of any WB up{>er air station. A cost comparison with other hydrogen sources showed that the Electrolytic Hydrogen Generator would not be eco- nomical at most facilities in the conterminous States; how- ever, considerable savings could result if it were used at arctic and tropical stations. During the last 2 years, the EDL was also responsible for developing new concepts for upper air measurements to improve the WB's capability for describing the state of the upper atmosphere. This study included developing a system to use the NAVAIDs — Loran-C and Omega — for measuring winds aloft, and also making a feasibility investi- gation into the use of several remote-sensing techniques. To develop a winds-aloft measuring system utilizing Loran-C and Omega, EDL first developed several Loran-C and Omega receivers which were then added to the tradi- tional radiosonde flight packages. Supporting ground equip- ment and engineering services for the new systems were obtained from a contractor. As a part of this effort, a Loran-C time difference digitizer for use with the Loran-C tracker was fabricated and delivered to EDL in FY 69. Experimental flights were conducted with these NAVAID systems in FY 69 at the National Aeronautics and Space Administration's (NASA) Wallops Island, Va., Station to compare the accuracy of Loran-C and Omega with wind measurements from the Weather Bureau Radiotheodo- lite (WBRT) and Ground-based Meteorological Detector (GMD) systems and from the FPS-16 precision-tracking radar. These comparison flights showed that Loran-C is capable of measuring winds more accurately than the WBRT system that is presently in widespread use, while Omega provides an accuracy comparable to that of the WBRT. The design and analysis phase for the Loran-C and Omega wind- finding systems will be conducted in FY 70, and experi- mentation will be continued to determine the ultimate capa- bilities and limitations of the techniques, especially the geo- graphical coverage. The EDL also investigated the area of remote sensing for upper air measurements because such techniques have potential for eventually reducing the cost of upper air ob- servations. Three different techniques were considered by EDL for potential WB use: (1) passive microwave tech- niques for measuring temperature profiles; (2) an acoustic radar for determining humidity profiles; and (3) Raman 36 backscatter for measuring the vertical profile of water vapor. In FY 69, a contract investigation was initiated by Sperry Rand Research Center to determine the microwave remote- sensing technique's altitude capability and its sensitivity to adverse weather conditions. With regard to the acoustic radar studies, EDL had procured all the hardware neces- sary to measure ambient noise and to create a sonic beam by the end of FY 69. Preliminary studies of the Raman scattering technique, based on theoretical considerations, have shown that the technique may only work in a clear atmosphere and would be seriously disturbed by clouds, fog, and even haze. PUBLIC WEATHER FORECASTS Service Programs The objective of the public weather forecasts program is to provide daily weather forecasts and to issue advanced warnings of adverse weather conditions — such as blizzards, heavy snows, cold waves, ice storms, hazardous driving conditions, frost, storms, tides, high winds, and sandstorms — to the general public through the distribution facilities of the mass media. also issue short-range (up to 3 hours) warnings before or during severe local storms. Weather information is distributed locally by the press, radio, and television over public service teletypewriter cir- cuits. The public may also receive information directly from automatic telephone-answering devices, over contin- uous very high frequency (VHF) radio facilities that transmit weather reports, through personal telephone calls, and by personal visits to the WBO. Large numbers of fore- casts, warnings, and other pertinent weather data are dis- seminated to the public by direct radio broadcasts from the WBO. As part of the continued implementation of the Nation- wide Natural Disaster Warning (NADWARN) System started in FY 67, VHF radio-transmitting facilities are being increased at more WBOs in an effort to expand the dis- semination of weather warnings to the public. This VHF service has led to a more rapid, efficient dissemination of warnings on tornadoes, floods, hurricanes, and other severe weather hazards to Federal, State, and municipal authorities concerned with public safety. Ultimately, such VHF service will be extended to each of the country's major metropolitan areas. Forecasting Public weather forecasts and warnings are prepared at Weather Bureau Forecast Offices (WBFO) serving a net- work of local Weather Bureau Offices (WBO). Certain of these WBFOs serve as Warning Coordination Centers is- suing special warning bulletins to the press, radio, tele- vision, Red Cross, State police, civil defense units, and other interested groups to alert all concerned public service organizations on impending hazardous conditions. Each WBFO develops state forecasts every 6 hours on the general weather conditions expected within its zone of responsibility — normally a single state, or a large por- tion of one or several small states — for 48 hours into the future, using guidance products furnished by the National Meteorological Center (NMC). Detailed weather forecasts for zones of 5,000 to 15,000 square miles in extent, having homogeneous atmospheric conditions, are also prepared by the WBFO. The local WBOs take weather observations for their area of responsibility; they also prepare warnings based on known weather hazards and localized forecasts based on the guidance of WBFO state forecasts. Localized forecasts or adaptations of state or zone forecasts take into account the climatology, topography, and general weather peculiarities of the limited areas to which they apply. Dissemination The WBOs throughout the Nation serve the public in their communities and surrounding areas by providing weather reports, advisories, forecasts, warnings, and gen- eral weather information. These WBOs disseminate fore- casts similar in content to WBFO zone forecasts except that the areal coverage extends to a major town or city and its suburbs, generally to a radius of 25 miles. Local WBOs Research and Development Programs The objective of the R&D program for public weather forecasts is to provide a basis for improved local service. Two approaches are pursued. In the first approach, the computer-processed products of large-scale numerical-dy- namical prediction models are refined to provide local fore- casts of specific weather elements. In the second approach, new prediction techniques utilizing statistical, climatological, and synoptic methods are developed for use by field fore- casters making the local forecast. Prediction Techniques Although there are separate R&D programs in public weather forecasts, many of the R&D programs funded in Basic Weather Services also support the public weather forecasts. One of the principal objectives of this support is to increase the use of numerical methods for both ex- tended and short-range forecasts. During the reporting period, the WB's Techniques De- velopment Laboratory (TDL) and Systems Development Office (SDO) conducted research involving several numer- ical prediction projects to improve public forecasting through the extension of NMC products to field fore- casters. Specifically, one TDL project was initiated to develop techniques and programs for automated prediction of sur- face temperatures and pressures. As a result, a completely automated system of predicting surface maximum and mini- mum temperatures 12 to 60 hours in advance at 131 U.S. cities has been developed, tested, and put into operation on a twice-daily basis. Another TDL project was started which adapted existing NMC large-scale numerical models to a smaller scale to 37 provide 3- to 18-hour predictions of precipitation within a zone of about 50 miles in diameter. From this project, subsynoptic advection model (SAM) forecasts were pre- pared and have been available since early 1968 on a twice- a-day basis over RAREP (Radar Report) and Warning Coordination (RAW ARC) circuits to 79 Eastern States cities. In October 1968, SAM forecasts were placed on a four-panel graphical chart sent to WBFOs twice daily. These charts display the probability of measurable precipitation iti 6- and 12-hour periods, the conditional probability of freez- ing precipitation, the sea level pressure, and the 1,000- to 500-millibar thickness layer. Still another TDL project was conducted to improve and automate the nationwide forecasts of probability, timing, and amount of precipitation for public and hydrologic use. Conditional probabilities of precipitation were computed for 108 cities in the United States. These forecast aids in- clude the unconditional probability of precipitation for 6-, 12-, and 24-hour periods by months; the conditional proba- bility by season as a function of precipitation during the previous period; and the conditional probability of various amounts if precipitation occurs. The TDL also developed precipitation forecasting tech- niques and methods for selected U.S. geographical regions during the last 2 years. Physical, statistical, synoptic, and dynamic procedures were combined to derive new and im- proved techniques relating precipitation to atmospheric cir- culation parameters. For example, an automated system was developed for predicting quantitative precipitation (in eight categories) during the winter season in nine river basins of the Tennessee-Cumberland River Valley for 1 to 3 days in advance. These objective forecasts have shown greater skill than subjective forecasts for 48 hours, but not as much skill as those for 24-hour projections. Field Forecasting ESSA's WB has been conducting various R&D projects to provide the local WBOs with weather analyses and fore- cast guidance to meet their specific local requirements, in- cluding predictions of rain, snow, and fog for local aviation and hydrologic forecasts. These forecasts are adaptations of state and zone forecasts. The WB's TDL continued its efforts to develop improved techniques for short-period localized forecasting. Efforts were directed toward techniques to forecast are probability of snow occurrence, amount of snowfall, and discrimination between rain and snow for major cities along the U.S. east coast. A synoptic and statistical method was employed, based on the assumption that perfect prognostic maps of pressure are available to the forecaster and that the prob- lem involved determination of the weather event from pres- sure field or other information. Results from the Northeastern States snow prediction study, performed under contract by New York University, indicate that simple, reliable techniques for predicting onset time and depth of snow or for discriminating between rain and snow are not yet available. However, certain statistical and synoptic information can assist the forecaster in making local snow decisions. Local forecasters can predict local onset time of snow by using the distance-time graph to de- termine the principal direction octant by the maximum correlation coefficient method and the approach speed of pre- cipitation from the linear regression coefficients. The study also found that the boundary layer potential temperature produced by the primitive equation (PE) model exhibited skill in the discrimination between rain and snow. Another TDL contract study with the Travelers Research Corporation was conducted to relate heavy snow occur- rences along the eastern seaboard to the position of the 850-millibar cyclones. Useful snowfall patterns were ob- tained for various storm types. The TDL also supported a contract study by the Uni- versity of Hawaii involving the improvement of objective techniques to permit forecasting up to 24 hours in ad- vance of the onset time and to determine location of heavy rain in that State associated with disturbances of synoptic and subsynoptic scale. This project involved investigations of the 24-hour rainfall accumulation patterns associated with various frontal positions in the vicinity of Hawaii. Included in the study were possible correlations of thunder- storm occurrences with "wet," "dry," and moderate fronts. It was also found that rain from decaying tropical storms is enhanced by cyclonic activity in the middle and upper westerlies. In FY 69, TDL also developed charts for 35 stations west of the Continental Divide; these charts give the 12-hour probability and average amount of precipitation as a func- tion of location and intensity of low centers at 850, 700, and 500 millibars. The charts were developed for use at local stations to give the field forecasters an objective tool for predicting the probability of local precipitation. As an aid to the local forecaster making predictions of visibility, fog, and low-level wind shear during the critical early part of the forecast period, the TDL conducted re- search on a project to develop techniques for analysis and short-period forecasts in the atmospheric boundary layer. This project involved the use of a mesoscale synoptic ap- proach which utilized 5 years of surface, tower, and radar data from the Washington, D.C., Mesonet as well as from other sources. A real-time test of the visibility forecasting techniques developed under this effort was conducted at the Washington WBFO from September to November 1968. The two objective techniques tested performed about as well as did the field forecasters. As part of the continuing efforts to help local forecasters, the TDL launched a study of the statistical relationship between actual weather variables and parameters forecast by numerical models. In FY 69, 3-hourly values of observed weather variables — including ceiling, visibility, total sky coverage, weather, dew point, wind, temperature, and pre- cipitation amounts — were obtained from the National Weather Records Center (NWRC) at Asheville, N.C. These parameters will be related to the output of numerical models. A total of 254 cities in the 50 States and Puerto Rico were selected for the study. 38 HURRICANE AND TORNADO WARNINGS Service Programs The aim of the hurricane and tornado warning programs is to furnish adequate warnings in sufficient time to enable the public to make necessary preparations for safeguarding life and property. Hurricane and Severe Storms Warning Preparation Staff personnel in the seven offices of the WB's Hurricane Warning Service maintain a close watch on areas of poten- tial or incipient tropical cyclones and produce and issue advisories or bulletins for the general public, disaster and rescue agencies, and salvage operations in threatened areas. These offices include the National Hurricane Center (NHC) in Miami, Fla.; Eastern Pacific Hurricane Center and Cen- tral Pacific Hurricane Center in San Francisco, Calif., and Honolulu, Hawaii, respectively; and Hurricane Warning Offices in Boston, Mass., Washington, D.C., New Orleans, La., and San Juan, P.R. The NHC provides hurricane forecasts for the Atlantic and gulf coast areas and is responsible for the Atlantic Hur- ricane Warning Service including the supervision of warn- ings issued in Boston, Washington, New Orleans, and San Juan. All warnings issued for those areas are based on large-scale surface and upper air analyses and forecasts, prepared every 6 hours by the Regional Center for Tropical Meteorology (RCTM) at the NHC. The San Francisco and Honolulu Centers provide forecast and warning services for the eastern and central Pacific, respectively. The hurricane advisories and bulletins prepared by the Centers and Warning Offices for the general public con- tain information on the position, intensity, direction and rate of movement, areas under watch or warning, areas under flood and tornado threats, precautions to be taken, and anticipated coastal effects of the storm. Special marine, aviation, and military advisories are prepared to give perti- nent information to these special users and to the military services. A special, cooperative hurricane-reporting network is maintained along the Atlantic and gulf coasts of the United States. At locations approximately 50 miles apart, the WB provides volunteer observers with standard weather-measur- ing equipment to obtain accurate readings of wind speed, wind direction, and barometric pressure for transmittal to the nearest Weather Bureau Office (WBO) . Special hurri- cane observations are received from the Cooperative Coast Guard Network. Hurricane surveillance is also maintained by use of Applications Technology Satellite (ATS) and En- vironmental Survey Satellite (ESSA) spacecraft. Tornado and Severe Local Storms Warning Preparation The National Severe Storms Forecast Center (NSSFC) at Kansas City, Mo., prepares and releases public watches for severe thunderstorms and tornadoes in the United States. These public watches are released to WBOs in af- fected areas for dissemination to the public. The local WBOs also originate tornado warnings on the basis of actual tornado sightings or radar indications and alert other WBOs in the path of the approaching storm. The Severe Local Storms (SELS) forecast unit of the NSSFC also prepares Aviation Severe Weather Watches for distribution to the aviation industry. Dissemination Warnings of both hurricanes and tornadoes are given immediate and widespread distribution by the WBOs in the affected areas through all available means of com- munication. Hurricane forecasts and warnings are disseminated by teletypewriter, radio, telephone, newspaper, television, and Government communications facilities. Forecasts and warn- ings are available simultaneously at all WBOs on the At- lantic and gulf coasts by special hurricane teletypewriter circuits. Local WBOs are responsible for releasing advisories and bulletins, issuing statements on the local effects of the hurricane, and distributing hurricane material for use in public education and preparedness information programs. Public watches on tornadoes and severe thunderstorms and warnings of such severe weather phenomena are dis- seminated in the affected area by the local WBOs through radio, television, telephone, and teletypewriter facilities. Aviation Severe Weather Watches are also disseminated to the WBOs, Federal Aviation Administration (FAA), and military offices in affected areas. Research and Development Programs ESSA conducts R&D programs on hurricanes and other severe cyclonic storm circulation to acquire increased knowl- edge of these hazardous storms; to apply this knowledge to improvements in techniques for storm detection, fore- casts, and warnings; and to develop possible means of storm modifications. ESSA's hurricane and severe storms R&D program efforts are initiated through research activities of the RL's Na- tional Hurricane Research Laboratory (NHRL), with sup- porting research in mathematical simulation augmented by cooperation with another RL component, the Geophysical Fluid Dynamics Laboratory (GFDL) . The WB's NHC uti- lizes products prepared by the NMC and conducts research studies into the problems of detection, development, struc- ture, modification, and forecasting of hurricanes; in addi- tion, the NHC has been studying techniques to forecast hur- ricane motion and investigating and making recommenda- tions on how to improve warnings to the public so that they will react and take the proper precautionary measures. In hurricane research, both RL and WB conduct a broad- based program on basic and applied research in techniques development for hurricanes and related tropical phenomena. Such programs will lead to improved forecast and warning services and may provide a possible means of diminishing the intensity of these severe tropical storms. The research program includes investigation of the structure, circulation, and energy sources of hurricanes and other tropical storms using data obtained by specially instrumented aircraft, weather satellites, and conventional weather observation 39 L I networks. Special studies are being conducted to provide insights into the nature of tropical disturbances; digital computers are used to develop mathematical models which simulate the atmospheric conditions of these tropical dis- turbances. Based on this fundamental work, broad programs of R&D are being carried out to improve the techniques available to the weather forecaster for predicting the for- mation, motion, intensity, and structure of individual hur- ricanes and other tropical storms. ESSA conducts R&D programs to obtain an improved understanding of tornadoes, squall lines, thunderstorms, and other severe local storms and to develop improved methods for early detection, identification, and prediction of these severe local weather phenomena. These efforts give direct support to the severe local storms warning program and provide knowledge needed in the weather modification pro- gram for the development of methods to modify severe storms. To conduct these programs, data are obtained from a high density network of surface meteorology stations, an instrumented tower, rawinsonde releases in urban areas, conventional and Doppler weather radars, atmospheric elec- tricity field monitors, and meteorologically instrumented aircraft. Local severe storms have been studied using time-lapse film pictures from ATS spacecraft. It is planned to make these pictures available in real-time to the NSSFC in the spring of 1970 as a pilot project to apply geostationary satellite technology to the severe local storms warning program. From the data collected, new information is obtained on the structure and dynamics of severe local storms, provid- ing a basis for the development of improved forecasting and warning techniques. Advanced techniques are developed for probes of the atmosphere by conventional and Doppler radars, and for the processing, displaying, and transmitting of information obtained by these techniques. Weather radar studies are conducted to interpret radar information in terms of the characteristics of atmospheric phenomena. Several research projects are conducted through the Na- tional Severe Storms Laboratory (NSSL) at Norman, Okla. A special cooperative severe storms network of 56 surface meteorological stations and a 1,500-foot instrumented tower, located in an adjacent area, collect the data for the re- search conducted at RL's Wave Propagation Laboratory (WPL) on the development of a Doppler radar system to expand the capabilities for studying air motions associated with storm systems. Other research work includes the sys- tem finding and analysis activity, severe storms measuring equipment development, and forecast technique develop- ment. In direct support of the severe local storms warning pro- gram, a systems planning analysis was conducted; special equipment and severe storms forecasting techniques were developed by the WB's Systems Development Office (SDO). The systems study was required for proper planning of im- provements to the warning program; the study included an analysis of user requirements and an evaluation of alter- native methods of providing required services to the public. Hurricane Forecasting and Prediction A new objective prediction technique was developed and given experimental use during the 1969 hurricane season. This method employs mean layer winds and geopotentials for a deep layer of the troposphere, the depth being pro- portional to the central pressure of the hurricane whose movement is to be predicted. A simplified primitive equa- tion (PE) model developed by the NHRL has been used to predict the changes in the smoothed flow for a 48-hour period; a point vortex representing the hurricane was trans- lated in this changing flow. The NHRL, with assistance from the NHC's hurricane specialists, has been using 1968 hur- ricane Gladys data for dependent case studies using this technique. During the reporting period, the NHC initiated research on the reassessment of the hurricane prediction problem which consists of three basic and interdependent facets: de- velopment, movement, and storm surge. Investigations were made into the usefulness of hurricane movement predictions whose accuracy depends mainly upon how precise the di- rection of movement can be computed; the direction of movement depends upon the interaction of circulation in high and low latitudes. This research project focused upon the difficulty in separating the transistory from conservative features for circulation at low latitudes. Unless these transi- tories are filtered out, the interaction factor will be poorly predicted. Therefore, emphasis is applied toward varibus prediction techniques. The storm surge for an ideal coast- line can now be modeled effectively, but research has shown that the variations caused by local topography can be of such magnitude that the problem must be attacked as a special case for each population center; the physical-dy- namical model employed was flexibly designed to accept a variety of topography. The NHC also developed an operational technique that utilizes a digital computer to define the climatological track of an existing tropical cyclone. All Atlantic tropical cy- clone tracks since 1866 were examined. Positions of storms that exhibited characteristics similar to the existing storm (adjusted to its initial position) were computed at 4, 12, 24, 36, 48, and 72 hours after the initial time. The tech- nique makes it possible to compute the probable position of the storm center relative to a given location at a spe- cific time. In an analogous project conducted by the National Me- teorological Center (NMC), experimental hurricane track forecasts to 72 hours have been computed for existing hurricanes by using as initial data the NMC's tropical belt wind analyses, followed by the PE barotropic forecast model calculation for the hurricane seasons of 1967, 1968, and 1969. These experimental hurricane track forecasts were telephoned to the NHC in Miami during FY 69. During the 1967 and 1968 hurricane seasons, this afore- mentioned procedure constituted the track forecast. Verifi- cations of these forecasts showed the forecast track to be .40 Hurricane vortex photographed from a satellite. south of the actual track in nearly all instances. During the 1969 hurricane season, vortex effects have been added to the earlier procedure. A version of this vortex effect procedure was successfully tested during the 1968 hurricane season. The NHC conducted an investigation into storm surge utilizing climatological data. Sufficient climatological data were available from 18 great hurricanes (950 millibars or less) to show variations and extremes in the water levels resulting from storm surge, enabling a mean profile to be constructed from these data. While the profile has initially been used as a first estimate of the lateral extent of danger- ously high hurricane tides preceding devastating hurricanes in low latitudes, NHC scientists are also working on an ad- ditional contribution to this concept by adjusting existing theoretical models before storm surge forecasts are made by the computer for each hurricane approaching land. Satellites are now used routinely to observe hurricanes and tropical cyclones. One such project involved the sum- marization of the characteristic features of lower tropo- spheric fields of motion, low-latitude synoptic scale, and weak members of the tropical cyclone family as determined from weather satellites, rawinsonde, and flight data. Quali- tative intensity estimates based on available data and known constraints were also made. These intensity estimates and constraints lead to estimates of growth, decay, fluctuation, and transformation and facilitate the application of needed flexible classification schemes. In another application of satellites to hurricane and tropi- cal cyclone observations. Nimbus 2 High Resolution Infra- red Radiometer (HRIR) measurements in the 3.4- to 4.2- micron region and ESSA 1 and 3 pictures were analyzed during the last 2 years to map the growth from West Africa of the 1966 hurricane Inez. The development of Inez passed through two intensity peaks in the tropical Atlantic and Gulf of Mexico before dissipation 28 days after its incep- tion. A new map projection form was used to analyze sta- tistically the cloud field associated with the various stages 41 of hurricane development. This map projection centers the analysis over the storm and retains some scale regardless of the storm's position. Tropical sea-surface temperature charts in the vicinity of Inez were also derived from Nimbus 2 HRIR data for 10-day periods during September and October 1966. The availability of satellite pictures has made it possible to document the history of weak tropical disturbances over the North Atlantic Ocean. Such documentation was made through analyzed results from the most recent hurricane sea- sons — 1967 through 1969. More than one-half of the dis- turbances originated in Africa. Moreover, a number of these African disturbances were followed across the Carib- bean and into the eastern Pacific Ocean where they occa- sionally triggered tropical storms. The research done by Ballenzweig in the 1950's was up- dated by NHC using a slightly different approach which computes the departures from 10-day normals for the day that hurricane intensity was reached and for the preceding 2 days. Mean 700-milIibar maps for these 2 days are ex- amined to assess the vulnerability of landmasses being re- lated to the actual landfall of hurricanes. Additionally, the NHC, in cooperation with the NHRL, performed an analysis of forecast errors for the past two hurricane seasons. This includes the construction of proba- bility ellipses for the official forecasts based upon case errors. The new verification program is based upon a digital hurricane advisory that may be introduced operationally in the near future. With the establishment of a Hurricane Services Branch at the NHC in 1968, four hurricane specialists have been assigned full-time duty in this Branch. The specialists have been improving diagnostic tools and automating procedures. Attention has been given to the development of new and more comprehensive climatological tools for prediction and the development of objective procedures for storm surge predictions. Programs have been completed for automated processing of upper air information in tropical and equa- torial areas, for computation of mean tropospheric layer winds and mean geopotentials, and for plot-out of data on map bases. A number of other programs have been devel- oped to prepare daily computations and printouts of devia- tions from normal, 24-hour changes in meteorological ele- ments, and other diagnostic information. Hurricane Modification Experiments The program for hurricane modification experiments. Project Stormfury, is conducted in cooperation with the Navy and with support from the Air Force. Experimental flights have been made into hurricanes to investigate the feasibility of seeding supercooled clouds with silver iodide, under the hypothesis that the release of the latent heat of fusion in certain sectors of the storm's structure will produce changes in the pressure gradients or in areas of divergence that will either change the intensity of the hurricane or its direction of travel. During FY 69, NHRL initiated a study of hurricane modification by reducing the rate of heat and energy transfer from the sea to the atmosphere inside the storm's circulation. Theoretical Investigations and Models Encouraging results have been obtained from NHRL's multilevel PE model of tropical cyclones; numerous inte- grations have been carried out with results that resemble the life cycle of real tropical cyclones. Results obtained so far have encouraged attempts at simulating some of the field experiments planned by Project Stormfury. Extensive studies of a two-level balance hurricane model were in progress during FY 69 to determine boundary layer effects on tropical cyclone development. A PE version of this model has also been devised and programmed for direct studies of the effect of the gradient wind assumption on results obtained from hurricane models. Hurricane Structure and Energetics The NHRL has conducted a series of research programs to give a more complete understanding of hurricane struc- ture and energetics for designing modification experiments and improving forecasting techniques. An intensive study of the 1964 hurricane Hilda from the formative through the decay stages did much to establish these earlier tentative findings. Warming aloft precedes deepening to hurricane intensity; characteristic cloud forms occur during and after intensification; earlier energy budgets for momentum, heat and moisture transfers, and kinetic energy were confirmed by research aircraft data; and the greater part of latent heat transfer occurred at relatively large radii, but the trans- fer was more intense closer to the ring of maximum winds. The same research approach was applied in a shorter study of the 1966 hurricane Inez — a very small, very intense, typical Atlantic hurricane. Data collected by flights near and above the top of the 1966 hurricane Faith were analyzed to fill gaps in knowledge of temperature, wind, and pres- sure distributions near the tropopause over severe hurri- canes. Results obtained were used in evaluating hurricane simulation experiments. Diagnostic Studies of Other Tropical Systems The study of hurricanes was supplemented by research on other tropical disturbances that can thrive under the same conditions. A seven-level diagnostic model has been developed that includes frictional convergence of moisture in the low levels, idealized and parameterized release of heat in the vertical, stream function and geopotential heights related through the balance equation, and a tabulation of contributions by the various terms in vorticity and thermo- dynamic equations. Other studies made include: An evaluation of aircraft data gathered on a synoptic experiment in the tropics (Project ECCRO — Eastern Caribbean Cooperative Recon- naissance Operations) in studying the structure of a steady- state cold low (in the tropics) relating circulation to mois- ture, cloud, and precipitation patterns; and a study of the evolution of the wind and temperature fields of two tropical disturbances crossing the Caribbean, one of which remained a steady-state easterly wave and the other deepening into the 1962 hurricane Alma. 42 Forecasting Hurricane Motion A multilevel PE model for hurricane forecasting has been developed and programmed at NHRL. The model has been tested on nonhurricane data for a relatively small geo- graphical area. In the case of hurricane Alma, the model successfully forecast the development of a vortex. The move- ment of the developing cyclone was also successfully pre- dicted. Continued tests of the PE model on Alma and the 1965 hurricane Betsy data were also conducted in FY 69. Equa- tion derived as part of the prediction model were used to analyze vertical motion patterns and energy transformations associated with several tropical weather systems, including easterly waves, tropical cyclones, and an upper tropospheric cold low. Research Flight Facility In support of both research in hurricanes and severe local storms, ESSA's RL maintains the Research Flight Facility (RFF) headquartered at Miami. The RFF uses aircraft specifically instrumented for meteorological research to penetrate hurricanes and to obtain meteorological data in the vicinity of squall lines (tornado-spawning clouds) and other severe local storms. These aircraft gather meteor- ological data at various atmospheric levels up to their maxi- mum operating ceiling of about 20,000 feet. One of RFF's aircraft has a greater maximum operating ceiling, permit- ting its use to obtain meteorological data at elevations be- tween 30,000 and 43,000 feet. Other RFF aircraft are used for testing meteorological instrumentation and for making meteorological measurements on appropriate storms. During those seasons of the year when hurricanes and severe local storms are not prevalent, RFF aircraft are employed in projects which provide data needed for weather modifica- tion, snow storms, and other investigations. Tornado and Severe Local Storms Forecasting Work continued during the reporting period in the Tech- niques Development Laboratory (TDL) of WB on the de- velopment of computer-oriented techniques used by the NMC to predict the areal location of severe weather outbreaks and the measure of expected intensities and to verify severe weather forecasts. During the latter part of FY 68, three programs — trajectory, tornado indices, and verification — were run daily. Verification of 24-hour temperature fore- casts produced by the trajectory program during June 1968 indicated considerable improvement. A major achievement by the TDL in FY 69 was the de- velopment and successful testing of an operational three- dimensional trajectory model which produces skillful 24- hour forecasts of temperature, dew point, relative humidity, and net vertical displacement at the surface, 850 millibars, and 700 millibars. These computer forecasts are transmitted twice daily from NMC to the Weather Bureau Forecast Offices fWBFO) by means of facsimile. Use of this new information by forecasters at NSSFC is expected to im- prove significantly the accuracy of tornado and severe storm forecasts. The TDL and NSSL worked together to develop an analy- sis-forecast system for the NSSFC, a comprehensive sys- tem which included: (1) automatic data processing; (2) objective and diagnostic analysis; (3) prediction capabil- ity; (4) output and display of information; and (5) veri- fication. Both dynamical and statistical models were used. During FY 68, a system was designed to provide hydro- static checking of upper air data. A computer program which provides an objective analysis of the low-level mois- ture field was put into operation at NSSFC in April 1968. In FY 69, a modified version of the Bushby-Timpson 10-level fine-mesh PE model was developed and utilized to study the dynamics of the atmosphere in severe storm situations. Severe Storm Morphology and Dynamics The NSSL has begun research efforts aimed at the de- velopment of a comprehensive description and explanation of severe storm characteristics. Investigations during the last 2 years indicated that the contribution of a previously neglected source of rotation for thunderstorms may be sig- nificant. The evidence suggests that large thunderstorms have a tendency to rotate, to be severe, and to move along trajectories not wholly explained by their rotational char- acteristics. Instrumentation and sampling techniques involving air- craft and balloons were developed to obtain data on up- draft location, speed and configuration, size of inflow areas, inflow flux values, and parcel trajectories in relation to in- dividual thunderstorms. These sampling techniques yielded additional information on the internal structure of storms and their energy budgets. Dramatic variations in the vertical distribution of wind and temperature near a severe thunderstorm were analyzed in detail, based on data from an instrumented 1.500-foot television tower and associated observations. These data indicated that vertical extrapolations of surface measure- ments may be invalid in regions which are influenced by cold air outflow from thunderstorms. Storm Hazards to Aircraft Safety A cooperative investigation involving the NSSL, the Air Force's Air Weather Service, and the Canadian National Research Council during the spring of 1968 produced flight data on turbulence and temperature gradients in the vicinity of major thunderstorms. Flights by B-57 aircraft provided photographic data on the distribution and growth of con- vective cloud tops above 40.000 feet. Turbulence and tem- perature-sensing equipment, provided by a British concern, were carried aboard aircraft flown over the tops of large cumulonimbus clouds. Flights were made by a Canadian National Research Council T-33 aircraft to measure turbu- lence at altitudes below 15,000 feet in the vicinity of thun- derstorms. Flights were also made between thunderstorms in areas where aircraft operators might be inclined to pene- trate a line of thunderstorms; these flights provided infor- mation on aircraft hazards in the vicinity of severe local storms. Based on the evidence derived from this cooperative aircraft observation program in Oklahoma, the NSSL staff 43 was able to collaborate with the FAA in developing that agency's Advisory Circular 00-24, Thunderstorms — a guide for airmen on minimizing the risks of hazardous flying conditions. Electricity of Severe Storms Because electricity associated with other features of se- vere storms is poorly understood, attempts were made in NSSL to measure areas of lightning activity and to relate them to areas of precipitation, locations of air, inflow and outflow, and the direction and speed of storm movement and development. Positioning measurements of intracloud lightning associated with a major tornadic storm in central Oklahoma were studied. Observations of lightning radiation were made with improved sferic recording equipment. Data obtained in these experiments appear to be significant and should lead to an understanding of the role of electrical energy in severe storm processes and their manifestations of precipitation and high winds. As a result of investigations by the staff of RL's Iono- spheric Telecommunications Laboratory (ITL), indications are that the radiation pulse train produced by intracloud lightning contains information about the effective height of the discharge and its position. This possibility was studied by NSSL in FY 69, and the sferic measurements of a tor- nadic storm were reexamined to derive three-dimensional distributions of the sampled lightning. DOPPLER Radar Techniques Reports on a unique 1966 experiment conducted by NSSL involving two Doppler radars were completed during the reporting period. These studies revealed many of the prac- tical problems involved in the determination of the true vector wind velocity with a system of Doppler radars, each measuring the spatial distribution of radial wind compo- nents. From these studies, the design of an improved Dop- pler radar and associated systems for processing Doppler data was possible. Weather Radar Interpretation Research into weather radar interpretation by NSSL involves two objectives: (1) Determination of the relation- ship between weather radar data and associated meteor- ological phenomena — rainfall rate, hail, and tornado occur- rences; and (2) development of effective means for analyz- ing and displaying the fields of radar data and the inferred associated parameters. Continuing staff collaboration be- tween NSSL and the Fort Worth, Tex., River Forecast Cen- ter resulted in improved knowledge of the relationship be- tween radar data and rainfall rate, and in advanced con- cepts for effective processing of radar data for river fore- casting. Substantial advances were made in defining the re- lationship between radar echo intensity of thunderstorms and associated rainfall which may lead to use of radar data in the national weather observing and reporting systems, ap- plication of radar data in severe storm detection, and identification and investigation of severe storm morphology and dynamics. In FY 69, NSSL used digital radar data collected at 15-minute intervals to examine the short-term stability of severe storm patterns. These data, unique in quantitative accuracy and comprehensiveness, offer promise for determining the association between storm events and other meteorological parameters. The Equipment Development Laboratory (EDL) of the WB in FY 68 conducted research on digitizing radar re- turns over a given grid, the digital value being indicative of one of six Z-levels of the intensity. This approach in- volved the interface of a video integrator digitizer with the output of the WSR-57 radar which formatted the radar return for near real-time transmission to a computer site. In FY 69, a systems engineering study on uses of digital radar data and on ways to digitize radar data was com- pleted. Thunderstorm Forecast Technique Development Thunderstorm forecast technique development was for- mally initiated during FY 67 as a collaborative research ef- fort between the staffs of the NSSFC and NSSL, and was di- rected toward improving operational techniques for analysis of the current state of the atmosphere and more efficient use of observational data. Significant progress was made during FY 68 in objective and automated analysis and data processing techniques. Objective analyses that resulted from this joint research effort included the low-level mois- ture field and calculations of the kinematic vertical velocity. Automated procedures for checking radiosonde data for hydrostatic consistency and coding errors were introduced and have resulted in significant increases in daily sound- ings usable at NSSFC on a real-time basis for severe storm forecasting and warning services. Research in FY 69 con- centrated on the development of a fine-mesh numerical model applicable to the study of the dynamics of small- scale weather systems. Data Acquisition and Processing A major objective of NSSL's R&D program in severe local storms is to acquire comprehensive and accurate data on the meteorological parameters associated with severe storms and to process these data into a useable form that meets the data requirements of NSSL. A digital recorder for the wind and temperature systems was installed on a 1,500-foot television tower. High-quality measurements of temperature and horizontal wind are now obtainable at 1-second intervals at the surface and at six levels up to 1,458 feet above the ground. In a joint program with the Army and the Air Force, observations were obtained from 10 closely spaced rawin- sonde stations during the spring of 1968. Simultaneous ascents were made at 60-minute intervals from all stations during important weather situations. The network of sur- face weather stations was augmented with an internal cross of 12 new stations spaced 5 miles apart. Sixty-one stations recorded continuously during the experiment, measuring such quantities as rainfall, temperature, relative humidity, wind direction and speed, and pressure. With the closer spacing and special arrangement of sta- tions, NSSL continued systematic measurements of pres- sure, temperature, and wind fields associated with such local severe storm features as tornadoes, shafts of hail, wind, and intense rainfall in FY 69. The analysis of the increased density of surface measurements in the vicinity of severe storms aided in the evaluation of severe storm models. A program to use tower wind measurements for computing the magnitude of the vertical shear of the horizontal wind between successive tower levels was underway during the reporting period. AGRICULTURAL WEATHER SERVICES Service Programs The Agricuhural Weather Services (AWS) of ESSA's WB are designed to provide specialized weather observa- tions, forecasts, warnings, and reports to the agribusiness community as a supplement to the Basic Weather Services. The Department of Commerce (DOC), through ESSA, is responsible for planning and conducting the AWS. The Department of Agriculture (DOA) also assists in planning for the AWS and participates in cooperative programs for observation, communication, and distribution of informa- tion to users. The AWS's operational program involves specific weather forecast formats and techniques that are tailored to meet the needs of farmers, are devised by WB agricultural me- teorologists, and are disseminated daily through rapid communications outlets. Technical studies in meteorology, directed toward meeting the weather forecast needs of agri- culture, are conducted by agricultural meteorologists in cooperation with agricultural scientists at major Agricul- tural Experiment Stations throughout the country. Weather plays an important role in almost all phases of agricultural production. Agriculture decisions related to or influenced by weather include: (1) time of planting, method, and depth; (2) type of time and frequency of pesticide application; (3) soil cultural practices; (4) harvest sched- ules for equipment and crews; and (5) livestock production. Individual weather-influenced decisions in agriculture fall into two broad categories. The first type consists of those weather factors against which protection can be provided or positive action can be taken; for example, protection against frost, drought, or strong wind. Continuous protec- tion is possible against certain weather phenomena although it may be expensive or impractical. The optimum decision may range from no protection to continuous protection, de- pending upon the value of the enterprise, the cost of pro- tection, and the climatic probability of occurrence of the weather phenomenon in question. The second type of weather-influenced decisions con- sists of those weather factors in which continuous protection cannot be provided or continuous positive action cannot be taken; for example, the protective or positive action to be taken against rain at haying time would be to delay the cut, but such a delay cannot be continued indefinitely without decreasing the quality of the hay or without inter- fering with other crop schedules. Adequate weather observations, forecasts, and advisories can play an important role in many types of costly farm management decisions. Technical Studies Programs The effectiveness of the AWS is highly dependent upon a successful combination of knowledge from the fields of meteorology and agriculture. The need exists to apply the results from R&D in meteorology and agriculture to the AWS, and particularly to develop agrometeorology to meet the farmers' planning and operational problems. The degree to which weather information may be suc- cessfully applied to the solution of agricultural problems depends on several interrelated factors which include: (1) the detailed extent of crop or livestock response to one or more weather factors; (2) the climatic probability of oc- currence of several influential weather elements; (3) the ability of the meteorologist to establish the probability of occurrence of a particular weather phenomenon of sig- nificance in agricultural operation; and (4) the ability of the agriculturist to make and act upon alternative decisions, based upon timely weather information, which result in economic gain (or avoidance of loss). In meeting the requirements and objectives of the AWS, the cooperation of Agricultural Experiment Stations, Agri- cultural Extension Services, and Colleges of Agriculture is invaluable. The agricultural meteorologists, located at Agricultural Experiment Stations, have among their re- sponsibilities that of cooperating with Agricultural Experi- ment Station scientists in technical studies relevant to agriculture-weather relationships, and that of applying these relationships to the AWS and to farming practices. C.ollon lint moisture meter used to devise an objective method for forecasting early morning moisture content of cotton lint. 45 Tower, sensing equipment, and recorders for measuring temperature and humidity to pro- vide data for frost forecasts. Solar radiation, moisture, and temperature are key me- teorological elements in the growth and development of plants and animals. Plant growth and development are determined by the amount of insolation (solar radiation) that can be converted by the photosynthesis process into plant tissue. Farm animal production is controlled by the amount of available feed — forage, silage, and hay — and by the ambient environmental conditions in which the animals are grown. Soil moisture and temperature have an effect on the rate of seed germination and the vigor of young plants. Moisture in the soil, in the air. and on the leaves and stems of plants influences the rate of gro^vth of crops: the inci- dence and persistence of virus, fungus, and bacterial diseases on these crops are related to moisture. A major concern for agricultural scientists, extension personnel, and agricultural meteorologists is to establish the qualitative and, if possible, the quantitative relation- ships between weather and various phases of agricultural production. These relationships help establish requirements for meteorological information in various types of farm activities and alert meteorologists to agriculture's changing needs for weather information throughout growth, develop- ment, and maturation stages of plant and animal production. The increasing demand for water in agriculture to meet irrigation needs is an important economic factor for dry- land farming. Technical studies involving the measurement of soil moisture and prediction of water use over periods from 1 day up to 2 weeks are an important part of the AWS program in dryland agricultural areas. The quality of cotton has a high correlation with the moisture content of lint at time of harvest. Studies on the measurement and forecast of moisture at picking time are important to the cotton harvest. Many plant diseases are highly affected by moisture on the leaf surface. Technical programs to improve leaf wet- ness measurements and forecasts of dew duration are im- portant functions of the AWS. Technical studies on the in- fluence of weather on plant diseases are conducted by plant pathologists and agricultural meteorologists through con- tinuous spore sampling in field plots, continuous dew re- cordings for the area, and collection of disease data during the growing period. Fruit production, from blossom to harvest, is highly sus- ceptible to low temperature. The ability of the farmer or orchardist to protect his fruit crop against damaging low temperatures depends to a large degree upon the thickness of the critically cold air layer above the ground. Agri- cultural meteorologists gather data for forecasts of mini- mum nighttime temperatures and estimates of heat require- ments to prevent frost damage. AIR POLLUTION SERVICE Service Programs The air pollution programs of ESSA support Federal, State, and local pollution abatement and control activities. These programs include specialized meteorological fore- casts Tsuch as the daily Air Pollution Potential Advisories), climatological studies, and consultative services. The Air Quality Act of 1967 gives the Department of Health. Edu- cation, and Welfare (DHEW) responsibility for designat- ing Air Quality Control Regions within the country, for establishing air quality and pollutant emission standards in those Regions, and for controlling air pollution in non- continuous Regions of the country. Meteorological support is needed for these Regions be- cause atmospheric processes materially affect the transport and dilution of pollutants. The DHEW. the lead agency for air pollution control in the Ignited States, has designated ESSA to provide meteorological research and operational weather support to the Air Quality Control Regions. 46 Research and Development Programs Air pollution R&D programs in ESSA for the Air Pol- lution Service are conducted both by the WB and RL's Air Resources Laboratories (ARL). As an essential part of this Service, large-scale Air Pollution Potential Advisories are prepared by the WB's National Meteorological Center (NMC). These Advisories provide advance notice of poten- tially hazardous air pollution conditions for use as large- scale guidance by field forecasters who prepare specialized forecast products on the atmospheric potential for dilution and dispersion of pollutants over discrete portions of the conterminous States. The forecast products are based par- tially on computer-produced predictions of the height of the atmospheric mixing layer and wind speed within this layer where pollutants are normally entrapped. The ARL perform R&D on meteorological diffusion, trans- port, and deposition of atmospheric contaminants to attain a greater understanding of processes controlling atmospheric pollution and to find prediction and abatement procedures. Special meteorological activities are performed for the Atomic Energy Commission (AEC) and for DHEW's Na- tional Air Pollution Control Administration (NAPCA) . Oj>erational and consultative meteorological services as re- quired are provided by ARL to all activities of the NAPCA. Meteorology of Air Pollution Although funds within the WB are not specifically ear- marked for air pollution meteorology R&D, the need for improved air pollution forecasts has resulted in the estab- lishment of ad hoc applied research programs at both the NMC and various Weather Bureau Forecast Offices (WBFO). The WB research activities are concerned with predicting the atmospheric potential for air pollution and with determining the efficiency and effectiveness by which the atmosphere dilutes and disperses emitted pollutants. The level of air pollution potential varies directly with the thermal stability and inversely with the transport wind and mechanically and convectively produced wind turbulences. Problems in air pollution meteorology concern the choice of variables for describing these relationships and the ability to predict their future values. Research in air pollution meteorology by ARL includes studies on transport and diffusion, urban diffusion model- ing, air pollution potential forecasting, dilution climatology, mesostructure within the urban boundary layer, and effects of urban air pollution on weather and climate. Current methods employed by the WB to predict air pollution poten- tial are based partially on early R&D work by ARL. The Development Division of the NMC is working upon a "stagnation index" model based on several byproducts of the primitive equation (PE) numerical prediction model. The emphasis is to determine those critical values — relative humidity, lifted index, vorticity and vorticity change, 850- millibar temperature change, and boundary layer winds — considered as functions of known air quality variations which are available from the operational numerical model to use as input to a macroscale atmospheric stagnation in- dex. Concurrently, research is being done to improve fore- casts of mixing height and of transport wind within the mixing height. The WB established Environmental Meteorological Sup- port Units (EMSU) in several major cities during the clos- ing months of the reporting period. These Units observe and predict occurrences of high air pollution potential over urban areas. The major R&D effort by the EMSUs inte- grates the mesoscale effects on climate produced by the physical attributes of the cities with the synoptic scale air pollution potential. Each city has a unique heat budget, pol- lution, and topography which contributes to the generation of a local climatic regime. The problem is to determine how the mesoclimate of each city can be used to predict local weather variations and to particularize the pollution poten- tial forecasts for the urbanized area. Using urban low-level soundings and available air quality data, the EMSU meteorologists are trying to establish a statistical relationship between meteorological variables and pollutant concentrations. The assumption made is that good linear relationships are probable between pollutant concen- trations and local wind vector, stability, and inversion height and intensity. The development of local statistical models is underway so that mesoscale predictions can be improved. During the last 2 years, a comprehensive investigation of the transport and dispersion of plumes from 800-foot stacks at a coal-burning power station complex in western Pennsylvania was initiated by ARL under contract to NAPCA. Measurements of plume rise, plume geometry, and disf>ersion by instrumented helicopter and mobile Lidar (light detecting and ranging) were made. An analysis of data from low-level tracer tests, conducted in the St. Louis, Mo., metropolitan area, revealed numerical urban effects which enhance plume dispersion. Tabulations of mixing depths and vertically averaged wind speeds for 41 WB upper air stations are being analyzed to yield an air pollution potential climatology for the con- terminous States. Research continued on the development and validation of urban diffusion models and quantitative air pollution potential forecasts. The relationship between atmospheric turbidity and aerosol pollutants remains under study, and research is being pursued on the role of am- bient temperature and ultraviolet radiation in the creation and decay of photochemical air pollutants. Studies on the thermal and motion fields in the planetary boundary layer are directed toward the simulation and de- velopment of techniques for forecasting boundary layer parameters used in models of urban dispersion processes, and toward the development and validation of a "mass- balance" model of photochemical air pollutants. Results from several pilot field studies in the Cincinnati, Ohio, metropolitan area indicated that unexpected modification of the thermal structure of the surface boundary layer oc- curs over the urban area during nocturnal inversion con- ditions. Comprehensive national surveys of climatological air pol- lution potential and atmospheric turbidity were completed during the reporting period. Annual and seasonal ground- level concentration distributions for selected air pollutants 47 I were provided as meteorological input to Air Quality Con- trol Regions. Mesoscale Transport and Diffusion The aerodynamic effect of a large urban building com- plex upon atmospheric diffusion rates was determined quan- titatively by tracer experiments; these experiments measured the downwind concentrations in actual flow and also esti- mated such concentrations from undisturbed flow turbulence characteristics. Research revealed that increased dilution rates by a factor of about three were present at distances 600 meters downwind. Another field experiment was initiated to study the aero- dynamic effect of a single rectangular or cylindrical build- ing upon atmospheric diffusion rates. This experiment in- volved an investigation of the relationship between surface boundary layer turbulence characteristics and surface depo- sition of submicron particulates. In a continuing study of internal boundary layer struc- ture above marsh grass surfaces, measurements of vertical velocity were made to study turbulence characteristics. Spectral density estimates of the vertical wind component in the region of 3.5 Hertz were used to estimate the rate of kinetic energy dissipation. Values were found to decrease with height and to increase with wind speed. Relative diffusion at a height of 3 kilometers was studied by means of simultaneous tetroon (balloon) releases at the Nevada Test Site. In another experiment, 42 tetroons were tracked by radar past the 1,500-foot Bren Tower to obtain additional information for analyses of the ratio of Eulerian and Lagrangian wind scales. Global Diffusion and Stratosphere Radioactivity A study of the differences in behavior between particulate strontium-90 and gaseous carbon-14 in the stratosphere was completed. Results indicate that for time periods of 1 year or more, particulate fission products can be used as at- mospheric tracers below 30 kilometers; above this level, the fall rates of particles may become significant. These data, together with other radioactive tracer data, have been used in developing a kinematic model of stratospheric motions. The design and procurement of operational carbon-14 samplers were completed. A successful test flight at 21 kilometers of the newly developed balloon-borne molecular sieve carbon-14 sampler was conducted in February 1969. A test at 36 kilometers in May was also successful, but results from this test revealed that a modification of the filter beds may be necessary to achieve maximum collection efficiency at high altitudes. A technique has been developed for estimating rapidly the future worldwide deposition of long-lived radioactive debris injected anywhere into the atmosphere. Adapted to a computer, this technique will estimate the consequences of possible future atmospheric nuclear testing. Problems asso- ciated with short-lived radioactivities were also investigated. An airborne investigation of the radioactive argon-41 plume from the Brookhaven reactor in New York, using aircraft equipped with large silver-iodide crystal detectors and an onboard computer, has yielded data on plume be- havior 300 miles from the source. The role of the high-reaching thunderstorm activity in bringing iodine-131 to the surface has again been verified by studies in the Midwest; a more complete study of all instances of detectable iodine-131 in milk since the end of large-scale nuclear testing in the atmosphere was also made. Sonic Boom Investigations into sonic booms at Edwards Air Force Base, Calif., indicated that A'-wave overpressures correlated well with the Friedman overpressure prediction. Field surveys are being made to determine the optimum location for a microphone array at Pendleton, Oreg., and to delineate the superboom caused by aircraft acceleration; the Friedman computer program is being used to predict the location of the superboom for various flight configura- tions and to estimate the overpressures resulting from air- craft accelerations. Attempts will be made to obtain obser- vational verification of the superboom. Arrays are in place to collect meteorological data for comparison with the SR-71 sonic booms. During FY 70, an analysis of the Pendleton data will be made. Meteorology for Nuclear Testing To assist programs for testing nuclear weapons, rocket engines, and industrial nuclear explosives, applied research is oriented toward improvements in the meteorological services provided. Models of mesoscale meteorological cir- culations in geographic areas used for nuclear tests are developed and used with adapted diffusion and deposition models to provide evaluations of radiological hazards. Five radiological hazard models, based on diffusion computa- tion methods, were compared for use in nuclear rocket en- gine tests during the last 2 years. Long-range diffusion parameters were derived from data on the dispersion of tetroon clusters and from particulate tracer experiments. Effects of large directional wind shears on effluent deposition were evaluated and corrections in- cluded in fallout models. Statistical precipitation forecast- ing models and a climatology for the Nevada Test Site were completed. Progress toward a computer-oriented mesoscale meteor- ological system continued with acceptance of a commercial design for a portable wind-finding radar with a built-in computer interface. Another system contribution was me- teorological instrumentation for a 1,500-foot tower and for a long-range airplane. Research into deposition in flows over mountain bar- riers and on long-range diffusion continued. Additional progress is expected in adapting computer methods for analyzing streamlines in mountainous wind forecasting. Current diffusion and deposition models used to evaluate potential hazards from underground nuclear detonations were reviewed. New techniques for trajectory prediction are expected to evolve from studies of long tetroon tra- jectories. 48 Interoceanic Canal Meteorology Meteorological data — including wind profiles, trajectories, and surface and radar precipitation measurements — are re- quired to analyze potential fallout hazards that could affect the feasibility of constructing a sea level canal by nuclear excavation in Panama or Colombia. Data collection and analysis were completed, computerized fallout models were developed, and fallout patterns were calculated for the pro- posed excavation routes. Atmospheric Turbulence and Diffusion During the reporting period, the Air Resources Atmos- pheric Turbulence and Diffusion Laboratory (ARATDL) of ARL made a comprehensive study of the buoyant rise of stack plumes which are urgently required for atmospheric diffusion predictions. Principal findings of the ARATDL study concluded that: (1) Almost all existing plume rise data fit simple models in which buoyancy and momentum are conserved and plume diameter grows linearly with height; (2) under stable conditions, very buoyant plumes follow a "two-thirds power of distance" law of rise for con- siderable distances; and (3) under neutral and unstable conditions, ultimate heights of plume rise have not yet been observed. Theoretical studies of the planetary boundary layer have been continued; emphasis is on defining the top of the layer and comparing various planetary boundary layer models. WEATHER MODIFICATION Research and Development Programs The R&D program in weather modification has the poten- tial to benefit the Nation's economy, protect human life, and reduce property losses. Such a program is closely re- lated to other weather activities within ESSA and is guided by goals developed by the National Academy of Sciences' (NAS) Panel on Weather and Climate Modification and by the National Science Foundation's (NSF) special Commis- sion on Weather Modification. The Atmospheric Physics and Chemistry Laboratory (APCL) of the RL is concentrating its efforts primarily on research which develops the scientific and practical po- tentialities of weather modification and advances the re- quired technology for application of weather modification through theoretical studies, laboratory investigations, com- puter modeling of atmospheric processes, and experimental field projects. Present effort emphasizes modification of pre- cipitation, moderation of severe storms (including hurri- canes and severe local storms), reduction of hail and lightning damage, and possibility of climate modification either by man's deliberate actions or inadvertently by his normal activities. Hail and Lightning Suppression ESSA scientists, through cooperative arrangements with other research organizations in both laboratory and field Time exposure of multiple lightning strikes in an urban area during a typical thunderstorm. 49 investigations, are participating in the National Hail Modi- fication Research project to study hail-producing mecha- nisms. In the summer of 1968, a cooperative research pro- gram was begun during the hail season involving ESSA, Colorado State University, and the National Center for At- mospheric Research (NCAR) as participants, and receiving partial budgetary support from the NSF. Aircraft and sur- face observations were used in evaluating storm charac- teristics. Studies of the inflow and outflow circulation pat- terns, speed, and direction below the cloud base, the net divergence and vorticity, and the total water flow within the storm were undertaken. Airborne infrared-measurement techniques, used to determine hailfall patterns and intensi- ties, were evaluated; surface observations were made of hailstone characteristics and hailfall patterns. All aspects of this research have yielded valuable data for develop- ment of hail suppression methods. Studies are underway to develop techniques for altering the electrical characteristics of thunderstorms; this may ultimately lead to methods for suppressing or reducing the severity of lightning. Since 1966, lightning suppression studies have been carried out jointly with the Army. The aim of these studies is to eliminate lightning by using corona current to discharge the thunderstorm electric field before that field reaches values which trigger the lightning discharges. This research has led to detailed measurements of the electric field distribution underneath thunderstorms; from these measurements, a numerical model of charge de- velopment and distribution in the storm has been con- structed to provide information that is essential for effec- tive chaff seeding. Modification of Weather and Climate by Air Pollution Research is underway on the effects of industrialization, urbanization, and agricultural practices upon global and local climates. The role of air pollution is under study to determine its long-term effects on the natural climate of the earth. Specifically, the R&D program in air pollution deals with the radiation energy budget and with inadver- tent weather modification caused by the action of gases (carbon dioxide and ozone), particulate matter (cirrus clouds), and surfaces (albedo). As part of the R&D program, an additional benchmark air sampling station was put into operation during the reporting period with the establishment of a station at the Alpine and Arctic Research Institute facility west of Boul- der, Colo. The sampling programs at the Amundsen-Scott Weather Bureau Office (WBO) in Antarctica and at Mauna Loa Observatory in Hawaii were expanded. Research con- tinued on aerosols, radiation, and wind regimes along mountain slopes, electrification of warm raindrops, and development of an ion-gun to generate highly charged air pockets. One observer from the APCL participated in the 1967 global expedition of the USC&GS ship Oceanographer. A wealth of data on aerosols, atmospheric electricity, radi- ation, carbon dioxide content, and cloud nuclei was ob- tained. Similar measurements were conducted early in 1969 from the USC&GS ship Discoverer which participated in the Atlantic Trade Wind Experiment (ATEX) and from ships involved in the Barbados Oceanographic and Meteor- ological Experiment (BOMEX). Great Lakes Snow Modification In the Great Lakes region, intense snowstorms often para- lyze communities along the southern shores of Lakes Erie and Ontario. These storms are the result of flow of cold polar air over the relatively warm Lakes during the late fall and early winter. Exploration into these lake snowstorms has been carried out for several years; research results from a New York State pilot project on snow modi- fication revealed that very heavy seeding of the clouds just offshore could lessen disruptive aspects of storms by redistributing the snowfall downwind over a wider geo- graphic area on the lee side of a major lake. Images of snowflake crystals on the APCL's snowflake replicator. Other studies were conducted during the last 2 years on the dynamics of snowstorms over the Lakes. From these studies, which yielded a complete set of lake snowstorm char- acteristics, development of a theoretical model is now pos- sible. The microphysical development of lake snowstorms has been traced in terms of crystal growth, precipitation time, and advection distance of snow crystals. Experimental seeding of supercooled natural clouds to achieve complete glaciation, to minimize riming, and to advect more snow- fall farther inland appears feasible. Modification of Tropical Storms and Cumulus Clouds Tropical storm modification research increases knowledge of natural, artificially stimulated, or suppressed tropical convective activity and mechanisms involving isolated cumu- 50 lus clouds, thunderstorms, and tropical disturbances — both maritime and continental. Major research projects in this field include: Development and refinement of numerical computer models to predict more efficiently both the natural growth and decay processes of tropical cumulus clouds and their seedability under selected conditions; improvement and testing of more efficient and effective pyrotechnic cloud seeding chemicals, devices, and dispensing mechanisms from aircraft; development and refinement of a new generation Silver iodide generator for cloud seeding. Photo courtesy of U.S. Air Force. of airborne hydrometer sampling and recording probes and instruments; increased emphasis on the study of mecha- nisms involving warm clouds and their possible modification through use af a variety of seeding materials; determina- tion — based on data obtained at the surface, by aircraft, and from calibrated land-based radars — of changes in cloud and precipitation rate and amount that occur as a conse- quence of natural conditions and of seeding with silver iodide and other chemicals; and evaluation of data on both natural and artificially stimulated ice-crystal development and decay in convective activity as observed by airborne ice and liquid water (hydrometer) sampling devices. Northeast Rain Augmentation A theoretical study of cloud seeding potentialities in cy- clonic storms in the Northeastern States indicated that to augment the particle concentration will increase the rate of rain if the cloud has excess liquid water stored; more- over, the rain potential is greater in a cloud with a fluctuat- ing updraft than in one with a steady updraft. Research continued during the reporting period on rain augmentation from extratropical cyclones, using realistic updraft structure models as measured with Doppler radar. The eflfects of introducing the seeding agent from aloft (air- craft seeding) or below (surface seeding) were investi- gated. Instrumentation and Data Handling A rain gage that continuously monitors the amount of rain encountered in airplane flight was developed and flight tested. ^J>^ - • ■'*■■■ «**■ Results of localized seeding in cloud layer. Photo courtesy of U.S. Air Force. 51 Under development is a design for a panoramic real-time flight path and wind field display, with a centered radar- scope display overlay. This new design incorporates a small airborne computer for data handling and includes addi- tional output that provides the divergence and vorticity over a planar closed flight-loop. Computer programs for graphic presentation of several parameters have been written and tested. Immediately after the completion of the flight, graphic presentations are avail- able for application to various field experiments. FIRE WEATHER SERVICE Service Programs The objectives of the WB's fire weather programs are to protect life, to conserve natural resources, and to aid and stabilize the economy of the timber industry. These pro- grams have been focal points for the Fire Weather Service which provides weather forecasts and advisories to forest and range management, including fire control agencies in the United States. Annually, approximately 125,000 fires lay waste to 4.5 million acres of forest land in the United States. Tangible losses — damage to soil and wildlife, loss of stored water, and blighted recreation sites — ^bring the total annual cost to approximately 500 million dollars. In comparison, fire detection and suppression cost only 200 million dollars annually. Through effective weather forecast support, these losses are reduced and the cost of protecting forest and grassland areas is lessened. Weather conditions directly affect fire ignition, detection, and behavior. Proper weather information enables the fire fighting organization to time effective preventive action and to take immediate control measures. Day-to-day and hour-to-hour fire control operation must be keyed to exist- ing and anticipated weather conditions. organizations, county fire-fighting groups, private timber- land owners, and associations of private land users. Fire Weather Service forecasts are issued generally once or twice a day, but timing requirements vary with the needs of the local users. Weather information includes temperature, wind, humidity, timber and brush moisture, precipitation, and thunderstorm activity. Forecasts Cooperative Fire Weather Observing Stations, operated by forestry personnel, collect specialized data needed to make forecasts. Certain Weather Bureau Offices (WBO) are designated as WBOs for Fire Weather in the contermi- nous States and Alaska; these Offices are staffed with spe- cially trained WB personnel who furnish detailed forecasts to local users. During periods of unusually high fire danger, fire weather meteorologists prepare and issue warnings as required. Ad- ditionally, they release special forecasts covering the im- mediate vicinity of any fire. Meteorologists also consult with fire control coordinators on the probable effects of predicted weather upon fire danger to forests and upon fire control. Dissemination The Fire Weather Service is used by Federal agencies — Bureau of Indian Affairs, Bureau of Land Management, Forest Service, and National Park Service — State forestry , ~*i'' ESSA mobile fire-weather station. Research and Development Programs The objectives of the R&D program in fire weather con- sist of: (1) forecast techniques for such critical meteor- ological elements as temperature, relative humidity, wind speed, and wind direction; (2) forecast techniques for local- ization of thunderstorm activity; (3) procedures for small- scale analyses of weather elements involving typical air drainage flow in mountainous terrain; and (4) forecast techniques for important synoptic weather conditions such as strong dry winds. These R&D efforts also support the operational aspects of the Fire Weather Service. A large portion of the R&D program is directed toward improving the operations of the Fire Weather Service through better forecasts for local areas. Preliminary analy- 52 ses are made of weather conditions associated with fire dangers, based on detailed reports from forest ranger sta- tions throughout the country. Development and testing of the approved fire weather forecasts are based upon these analyses. Forecasting Techniques The Techniques Development Laboratory (TDL) of the WB is responsible for the development of objective fore- casting techniques for fire weather. These techniques in- volve predictions of temperature, relative humidity, wind, precipitation, and thunderstorms for selected stations throughout the United States. The TDL in FY 68 developed an objective system of map typing to stratify data. Statistics were computed for bimonthly grouping of data at the 23-station Fire Weather Network in southern California. Additional research in- volved planning a program to determine map types for this Network. In FY 69, multiple regression equations were derived for nine of 13 fire districts in Alaska. These equations used such predictors as mean layer values of mixing ratio and temperature, thickness, temperature-dew point spread at several levels, and wind velocity at the surface and 500 millibars. The predictands are the occurrence or nonoccur- rence of thunderstorms and the number of thunderstorms encountered during a 12-hour period. In addition, single- station multiple regression equations were derived for pre- dicting surface dew point at 89 cities in the conterminous States from circulation forecasts made by the primitive equation (PE) model. AVIATION WEATHER SERVICES Service Programs The Federal Aviation Act of 1958 defines ESSA's responsi- bility to the aviation community as that of supplying ade- quate aviation weather programs to promote the safety and efficiency of air navigation. The aviation weather programs of the WB are incorpo- rated into Aviation Weather Services which furnish the spe- cialized weather reports, forecasts, warnings, and advisories required to serve aviation. Specialized weather reporting contributes to the safety of aircraft operations in the Na- tional Air Space System by providing information which assists pilots to avoid or minimize the effects of potentially hazardous weather conditions — such as turbulence, icing, strong winds, and fogs. Such reporting also contributes to the efficiency of aviation operations by furnishing informa- tion which assists managers, pilots, and controllers to de- termine and select optimum cruise levels, tracks, fuel, and payload ratios; to alleviate air traffic congestion; to reduce aircraft delays, diversions, and missed approaches; and to improve planning for effective System utilization of aircraft crews and facilities. Increasingly, Aviation Weather Services become more important as the national economy expands, as vigorous aviation growth continues, and as air space congestion per- sists. Because weather is an important related factor in many general aviation accidents, it is a matter of vital safety that forecasts and warnings be adequate and timely. By im- proving Aviation Weather Services, the degree of hazard involvement in aircraft operations could be substantially reduced. ESSA's plans for improving the Aviation Weather Serv- ices are contained in Planning Guidelines for a Federal Aviation Meteorological Service, published in August 1968 by the Federal Coordinator for Meteorological Services and Supporting Research. These plans are in response to the requirements stated by the Secretary of Transportation in his letter of April 25, 1968, to the Secretary of Commerce, and follow the recommendations of the National Transporta- tion Safety Board. Aviation Weather Observations Weather observations are required by the Aviation Weather Services to provide the necessary weather reports, forecasts, and warnings. The Basic Observation Networks provide the surface, upper air, and radar observations from specialized and cooperative facilities. The specialized avia- tion observations primarily support airport landing and take- off operations. Large gaps in aviation observation reporting still exist, particularly in the mountainous Western States; additional observations are required to support safe air- craft operations adequately. Forecast Preparation The National Meteorological Center (NMC), the National Hurricane Center (NHC), and the National Severe Storms Meteorologist preparing forecast of flight weather conditions over the North Atlantic Ocean. 53 Forecast Center (NSSFC) prepare nationwide forecasts for domestic aviation as their contribution to the Aviation Weather Services. Using these nationwide forecasts, the Weather Bureau Forecast Offices (WBFO) prepare ter- minal forecasts for airports within their respective zones of responsibility. Twelve- and 24-hour terminal forecasts are prepared every 6 hours; these forecasts are updated continually to keep aviation interests informed of signifi- cant and changing weather conditions important to efficient aviation operations and effective flight planning. Twenty- two WBFOs also issue domestic aviation area forecasts and In-Flight Weather Advisories to warn pilots and controllers of potentially hazardous weather. International aviation forecasts are prepared in accord- ance with procedures established by the International Civil Aviation Organization (ICAO). The NMC and six WBFOs, in cooperation with the Canadian High-Altitude Forecast Center at Montreal, Quebec, provide forecasts used for in- ternational flight documentation and planning. These Offices and Centers also issue forecasts of significant weather that may be potentially hazardous to flight safety over extended international routes. Dissemination A cooperative dissemination arrangement exists between the WB and the Federal Aviation Administration (FAA) as part of Aviation Weather Services. Telephone, person- to-person, and mass dissemination briefing methods are em- ployed to disseminate aviation weather information to pilots. Individual pilot briefings for domestic flights are handled by FAA personnel at Flight Service Stations (FSS) and by WB personnel at Weather Bureau Offices (WBO). All pilot briefers, both FAA and WB, have certificates from the WB. A flight service quality control program is maintained by the WB to insure that individual pilot briefings given by either WB and FAA personnel meet standards for flight safety. Forecast texts, prepared and furnished to the FAA by the WBFOs, are given mass dissemination over the Pilots Automatic Telephone Weather Answering Service (PATWAS) and the continuous Transcribed Weather Broad- casts (TWEB) . Pilot briefings for international flights are furnished by WBO personnel. Research and Development Programs The objective of the R&D program in aviation weather is to provide basic improvements to the operations of the Aviation Weather Services. This broad objective is being attained through continuing efforts in systems analysis, and in the design, development, and testing of new and im- proved techniques and equipment that are applied spe- cifically to forecasting and clear air turbulence (CAT) oc- currences. Forecasting In the field of forecasting, major emphases are placed upon development of objective automated short-period ter- minal weather forecasts, improved en route severe weather forecasts, and new flight equipment and procedures to over- come problems that arise from the introduction of new aircraft. Specifically, R&D efforts are directed toward: (1) De- veloping a comprehensive and logical plan for Aviation Weather Services which would allow orderly modification to these Services as requirements dictate and as technology advances permit; and (2) testing and evaluating new equip- ment and procedures for improved measurements of both terminal and en route weather conditions. As part of the effort to improve overall aviation fore- casting, a Plan for the Aviation Weather Services was ini- tiated by the WB's Systems Development Office (SDO) in FY 69. This plan will identify the essential support char- acteristics required to provide adequate weather services for flying operations. The Plan will incorporate a review of available data to determine user requirements. Essen- tial information for planning decisions will be derived through application of simulation or analytic modeling tech- niques to assess cost effectiveness. A cooperative effort was undertaken with the FAA to develop a weather subsystem description for FAA planning use. A large data base perti- nent to this Plan, including forecasts of aviation activities through 1980, has been developed. One of the main thrusts of current terminal forecast re- search is the development of first-generation computer tech- niques to automate objective observations of such critical weather parameters as ceiling, visibility, and wind at air- ports. Through use of computer techniques, these param- eters can be continuously updated to provide predictions at these airports. Development of automated terminal forecasting techniques which could be applied frequently and rapidly to update forecasts at various air terminals was undertaken by the Techniques Development Laboratory (TDL) of the WB during the reporting period. Experiments were conducted to determine the optimum techniques for forecasting ceil- ing, visibility, and wind at selected terminals up to 12 hours in advance. Automated forecasts of ceiling and visi- bility, based on simple predictors and the network concept, were produced for eight airport terminals every 6 hours during a 6-month feasibility test period. Results demon- strated that the automated forecasts were feasible but not as accurate as subjective forecasts. Three- and 8-hour ceil- ing and visibility prediction equations, based on more com- plex and physically oriented predictors (Boolean combi- nations), were developed and tested for Seattle, Wash.; similar studies were started for Los Angeles and San Fran- cisco, Calif. Equations based on Boolean predictors alone were not as good as equations based on simple predictors. In FY 69, the Test and Evaluation Laboratory (T&EL) launched a major effort to develop objective measures of ceiling and visibility. The short-range goal is to develop in- creased knowledge on the performance and characteristics of current sensor technology; the long-term goal is to auto- mate completely the aviation surface weather observations. In the visibility phase of this study effort, a review of cur- rent visibility observation methods and instruments was completed. For cloud measurements, numerous ceilometers were instafled and the experimental program to collect quan- 54 titative data on their performance was initiated. Procure- ment was started for a light detecting and ranging (Lidar) system which will be used to provide quantitative definitions of cloud boundaries and sky cover. The T&EL and FAA jointly funded a R&D contract to Stanford Research Institute in FY 69 for development of a mathematical cloud model which would provide a theo- retical basis and specifications for an automatic system to describe the state of the sky. The parameters and relations needed to simulate cloud sensor characteristics will be in- corporated into the model, and the result will be a digital computer program that can be used to simulate the oper- ation of systems of sensors under a variety of sky conditions. The Equipment Development Laboratory (EDL) of the WB was involved in research to produce a digital height representation of clouds detected by the rotating-beam ceilometer (RBC). This project involved digital processing of a 120-Hertz signal to determine the presence and time of occurrence of peak cloud envelopes. The resultant device, an RBC Signal Peak Detector, was successfully developed in FY 69. This experimental digital processor, which de- tects a cloud signal, generates an output pulse after its maximum amplitude has been found, and displays the ele- vation angle of this peak digitally. The device will be em- ployed by T&EL in its study to automate cloud measure- ments. To achieve improved en route forecasts, TDL studied the correlation between tailwind components and temperatures at supersonic transport (SST) flight levels. Correlation data were prepared for 10 possible SST routes. A large volume of statistical data was assembled, but correlations appeared to be small. In another phase, TDL studied the variability of temperatures and winds at SST flight levels. While re- sults indicate that the 12- and 24-hour changes in winds and temperatures tend to increase toward the winter and with increasing heights above 50 millibars, forecasts based on 12- and 24-hour persistence would be adequate for SST cruise operations most of the time. Clear Air Turbulence (CAT) Rapid technological developments have emphasized a need for analysis and prediction techniques to determine the location and intensity of CAT. The effort has resulted in: (1) systematic analysis of special pilot reports on oc- currence of CAT over North America and surrounding geographic areas; (2) development of preliminary empirical relationships, important for studying the location and in- tensity of CAT occurrences (intensity results are of value in aircraft design) ; and (3) a fine-scale analysis of CAT and upper air dynamics and structure to direct future re- search in locating CAT occurrences. In FY 69, the TDL performed an analysis of the meteor- ological conditions associated with CAT over North Amer- ica and the Atlantic Ocean during four 5-day periods of special data collection. Resuhs showed that a well-developed upper level circulation system is important to the develop- ment of CAT and that significant turbulence is almost as frequent over oceans as over land. TDL also started a study during the last 2 years to com- pare computerized mountain wave turbulence forecasts for the Denver, Colo., area with manually prepared forecasts and actual turbulence reports from pilots. A feasibility study was performed by EDL scientists to investigate the use of the existing rawinsonde network as a sensor for CAT. A computer program was developed that provides estimates of CAT probabilities as a function of rawinsonde accelerations. It was found that there is an in- creased probability of CAT when the rawinsonde accelera- tions are known to be small. MARINE WEATHER SERVICES Service Programs The Marine Weather Services (MWS) of the WB pro- vide forecasts, warnings, and other advisory information to support such marine activities as transoceanic, coastal, and Great Lakes shipping; commercial fisheries; offshore drilling and mining operations; and recreational boating. By international agreement involving the Safety of Life at Sea Conventions and the World Meteorological Organiza- tion (WMO), certain nations have the responsibility to furnish weather services for specific oceanic areas. The United States has such a responsibility for supplying weather services to users in the western North Atlantic and in the eastern and central North Pacific. Timely warnings of severe storms and other marine haz- ards contribute substantially to the safety and efficiency of marine operations. Advisories are broadcast regularly for use on the high seas to guide ships around severe storms and to direct ships to their destinations by selecting the most economical (timesaving) routes. Forecasts and ad- visories of ice conditions in polar seas and the Great Lakes are essential for marine planning, shipping, and fishing activities. Small boat operations are particularly vulnerable to local changes in wind and sea-state conditions. Forecasting and Dissemination Marine forecasts for the oceans are prepared by Weather Bureau Forecast Offices (WBFO) at Washington, D.C., San Francisco, Calif., and Honolulu, Hawaii, based on guid- ance products distributed by the National Meteorological Center (NMC). The marine weather forecasts of these Offices are broadcast two to four times daily by Coast Guard, Navy, and commercial radiotelegraph and radiotelephone stations. Shipping forecasts for the Great Lakes are furnished by the WBFOs at Chicago, 111., Detroit, Mich., and Cleve- land. Ohio, while forecasting services for coastal waters and inland lakes and waterways are provided by certain specified WBFOs. Forecasts are distributed also by the ESSA Weather Wire and other means to commercial radio and television stations for broadcast lo the public. The WB's very high frequency (VHF) continuous radio facilities include marine warnings, forecasts, and observations for coastal areas. 55 Research and Development Programs To provide a proper technological base for increased marine weather activities, a broad R&D program in marine weather has been conducted. Increased national interest and activity in the marine environment and the need to supply information on current and anticipated weather conditions in support of marine environmental operations have led the WB to participate vigorously in a coordinated national effort for expanding the MWS to meet the Nation's growing needs. The WB's responsibility in this field is outlined in policy directives based on the Marine Resources and Engi- neering Development Act of 1966. Major benefits from the R&D program in marine weather lie in improved MWS which provide more accurate, timely, and detailed marine forecasts and warnings to the populous coastal regions of the country, to the growing millions of recreational boatowners who use inland lakes and water- ways and coastal waters, and to commercial fishing, ship- ping, and other industries that operate in the marine en- vironment. Systems Analysis A major emphasis of the R&D program in marine weather has been the development of a systems approach to provide the basic planning framework for future operations, par- ticularly to identify key technical obstacles to future im- provements. Fundamental to improved services is a better description of current marine weather conditions. Because merchant vessels of all nations routinely ply the oceans, such ships, if properly equipped, are capable of acquiring needed marine weather observational data. The potential for using these "ships of opportunity" as floating meteorological stations within the Automated Mer- chant Vessel Reporting (AMVER) System was studied dur- ing the reporting period by the WB's Systems Develop- ment Office (SDO). A computer program was devised and programmed to analyze U.S. and foreign ship traffic patterns to determine those portions of the oceans from which marine weather observations would become readily available if a number of these ships were instrumented. The computer program also prepared analyses of traffic patterns, density, and continuity from the AMVER ship traffic data. The study, concluded in FY 69, showed that from a cost-performance standpoint, it is preferable to use merchant ships rather than Ocean Station Vessels (OSV) as platforms for upper air, surface, and oceanographic observations, at least in the Northern Hemisphere. Sensors A major requirement for the MWS are sensors capable of continual operation in the harsh marine environment. The Equipment Development Laboratory (EDL) of the WB conducted a study to obtain data on sensors, telemetry communications systems, and power supplies for use in the design of a meteorological data buoy. This study in- volved both a literature survey and actual testing of selected air temperature sensors within the marine environment. The sensors were installed on the Steel Pier in Atlantic City, Launching of an instrumented balloon for upper air soundings above the ocean. N.J., and data collected until November 1968 when the sensors were destroyed in a storm. Loss of these sensors precluded completion of the planned sensor comparisons. Forecasting Techniques Although adequate forecasting of the marine environ- ment requires more detailed observations, significant and much needed improvements can be made by proper utiliza- tion of existing data. To achieve this end, a forecasting techniques development program was initiated with research 56 Steps in ESSA's ocean wave forecasting program : (a) weather and sea state observations are made by ships and ocean stations; (b) data are transmitted direct to computers at NMC; (c) computer output is fed into automatic chart drawer; (d) newly drawn chart is run through facsimile machine for transmis- sion to coastal and high-seas forecast centers; (e) marine advisories are sent by teletypewriter to marine radio stations for broadcast; and (f) ships at sea receive forecasts by radio and use them to navigate more safely. eflForts that are concentrated on predicting wave heights and storm surges caused by local and distant storms. Re- search efforts on wave heights have led to the development of computerized techniques to forecast wind waves, swell, and combined wave heights in the open ocean. Similar techniques are being developed to forecast coastal waves and breakers and waves on the Great Lakes. An objective method was developed — for one location on the east coast — to forecast the surges that are caused by North Atlantic storms. Work is underway to extend this technique to other coastal locations and to include the effects of tropical hur- ricanes. An experimental technique to forecast wind setup (tilt of the lake caused by strong winds and storms) on Lake Erie is also under development. The Techniques Development Laboratory (TDL) of the WB conducted research during the last 2 years on im- proving forecasts of marine surface conditions, such as surface waves on the high seas, coastal waters, and large inland lakes. The major achievement was a wave forecasting program which became operational at the NMC in October 1968. This program produces twice-daily facsimile trans- missions of 24- and 36-hour forecasts of wind waves, swell, and combined waves for the Atlantic and Pacific Oceans. These transmissions were the first automated marine sur- face forecasts issued by the WB. Their accuracy was eval- uated at four OSVs in the North Atlantic and found to be generally superior to subjective forecasts prepared from the same data. This sea-and-swell forecasting program was later modi- fied by TDL to produce teletypewriter forecasts of swell in the island chain of Hawaii and the 1,000-millibar wind velocity in the Bering Sea region of Alaska. During the reporting period, TDL also compared several methods for forecasting waves on the Great Lakes, the Sverdrup-Munk-Bretschneider method, adjusted for fetch width, appeared best. A study was started to relate 1,000- millibar geostrophic wind forecasts to observed surface winds over the Great Lakes. The TDL also worked on the development of objective techniques to improve forecasts of storm surges — changes 57 Severe flooding isolating farmstead. in water level caused by atmospheric disturbances. The approach was based on a physical-statistical relationship. Through such an approach, the relationship of extratropical storm surges along the coasts to the offshore oceanic cir- culation can be determined. A similar relationship for the wind setup on Lake Erie can also be derived. Observed and calculated astronomical tides and storm surge data have been collected for eight east storm stations. These data will be used to develop a computer technique for forecasting extratropical storm surges along the Atlantic coast. With regard to storm surges on the Great Lakes, TDL in FY 69 derived forecast equations for the wind setup on Lake Erie at Toledo, Ohio, and Buffalo, N.Y., and tested the equations on dependent and independent data with en- couraging results. This method uses sea level pressure at nearby NMC grid points to forecast the wind setup by means of screening regression. A study effort to develop forecast techniques for wave and surf conditions over sandbars at the mouth of the Columbia River and at the entrance to Yaquina Bay, Oreg., was launched late in FY 69. This TDL project, contracted to Oregon State University, involves identification of wave direction, wave period, wave height, tidal flow, river out- flow, and pertinent weather conditions that make bar cross- ings hazardous. Movements, intensities, and any other par- ticularly critical characteristics of weather systems that generate hazardous wave conditions will be evaluated to permit test forecasts for such conditions. By the end of the fiscal year, plans had been completed for installation of an 85-foot Totem buoy off the Oregon coast. Storm Surges The RL's Atlantic Oceanographic Laboratories (AOL) continued development of numerical models to improve ESSA's storm surge prediction service. In FY 69, research was initiated to incorporate bottom stress time-history in the linearized equations of motion for storm surges in an effort to formulate a physical model of bottom stress which has a firm mathematical basis. Treatment in the past has been limited to initial values of the known driving forces or to a differential form containing only a limited amount of their time-history. The new approach is based on the premise that any fluid in a basin, which is subjected to driving forces, will reflect the history of the driving forces during its entire transient state. This approach suggests that bottom stress be treated in an integral form that in- corporates time-history of the driving forces. Preliminary results from use of an integral form are significantly differ- ent from those using a differential form, or only initial values, of the driving forces. RIVER AND FLOOD PREDICTION AND WARNING Service Programs On the average, the American economy suffers an an- nual loss of 60 persons and 1 biflion dollars in property damage from floods. A primary responsibility of ESSA's WB river and flood forecast and warning programs is to reduce these severe losses by warning the public of poten- tially dangerous river conditions. 58 Punched tape telemetering rain gage. Forecasts with a lead time of only a few hours can be effective in reducing property losses and in saving lives. For example, protection measures, taken as a result of WB warnings, decreased the total property damage by about two-thirds during the spring 1969 record-breaking floods in the Northern Plains States. In addition to forecasts of floods, the WB issues regular forecasts of river stages and flow volumes for many water- related activities — ranging from sports fishing to river trans- portation. Approximately one-sixth of the Nation's freight is moved by river and lake barges so that forecasts of river conditions affect the operations of this important transport system. Those responsible for planning and operating water-use systems need streamflow forecasts to operate those systems effectively and efficiently, be they farmers dependent upon irrigation or multimegawatt hydroelectric network oper- ators. Indirectly, every segment of the Nation's economy is affected by the quality and quantity of river forecasts. Data Collection To produce river forecasts, hydrologists requixe a con- siderable amount of real-time data. The basic sources of these data are networks of precipitation and river-stage re- porting stations. Most of these networks are funded for and operated by the WB, but many are funded and oper- ated through cooperative agreements with other Federal, State, and local agencies. In addition to data network in- formation, forecasts or observations are furnished by other WB or ESSA elements. These range from forecasts of pre- cipitation and temperature to the data gathered by radar and satellites. For instance, information on the extent of snow fields is produced operationally by ESSA's National Environmental Satellite Center (NESC). Radar observa- tions are used to define the location and extent and to esti- mate the intensity of rainfall. Data are available on a near real-time basis from 7,000 network stations which report to one of the Weather Bureau Offices (WBO) designated as River District Offices (RDO) or to one of those WBOs which collect and relay hydro- logic data. In either case, data are then relayed to the ap- propriate River Forecast Centers (RFC) for preparation of forecasts. Preparation of Forecasts and Warnings Although several Federal, State, and local agencies pre- pare individual forecasts to meet their particular require- ments, the primary source of public forecasts and warnings is the RFCs of the WB. These Centers issue routine and flood forecasts for approximately 1,800 points along the country's major rivers; limited number of RDOs, not sup- ported by the RFCs, issue forecasts for some 200 points. Forecasts vary from flash-flood warnings to seasonal snow- melt forecasts. In addition to producing and disseminating forecasts, the RFCs develop new and better forecasting procedures and correct and update empirical or pragmatic procedures in use. Statistical methods are employed to develop procedures for seasonal snowmelt and for 30-day outlooks and volu- metric flows, with heavy reliance placed upon historical data from ESSA's Environmental Data Service (EDS) and the Department of the Interior's Geological Survey. Presently, a considerable portion of such data are on magnetic tapes or punched cards which are suitable for direct computer analyses. High-speed digital computers are being used by all RFCs. Computers are particularly use- ful in producing forecasts, especially if the time between the issuance of a warning and the occurrence of the flood is short. Furthermore, large quantities of data necessary to produce river forecasts make the operational real-time use of computers most appropriate. Dissemination of Forecasts and Warnings After the RFCs have reduced and analyzed the meteor- ological and hydrological data and then produced forecasts, these forecasts are transmitted to the affected RDOs. The public is informed through the regular news media or in emergency situations by the Office of Civil Defense, by 59 I ESSA meteorologists appraising heavy snow cover in the Red River Valley of North Dakota. State and local police agencies, or by other public safety officials. The time lapse between actual observations of rain- fall and river conditions and issuance of the forecast or warning seldom exceeds 5 hours. Considerable progress is being made toward reducing this time lapse through the use of automated gages and communications devices. Even- tually, improved meteorological forecasts of heavy rain may be used instead of actual observations. Presently, weather forecasts are being used as criteria for internal WB alerts of possibly dangerous river conditions. Information Services Those responsible for planning and designing hydrologic structures have a great need for hydrometeorological analy- sis on which to base their decisions. The ;WB provides such service to other Federal agencies through contractual ar- rangements; this information is also available to other users through technical publications. These hydrometeor- ological studies relate historical records of precipitation to the resulting hydrologic events; the reliability of the results is dependent upon the length and quality of the historical records. Both empirical and statistical methods are employed. Research and Development Programs The responsibility for ESSA's R&D programs in hydrol- ogy rests with the WB's Office of Hydrology. Most in-house research is centered in the Hydrologic Research and De- velopment Laboratory at WB Headquarters in Silver Spring, Md. The work of the Laboratory is mission-oriented, with its primary objective to develop and test improved tech- niques for application in operational river forecasting. Most research is accomplished at the Laboratory; however, cer- tain projects are contracted to universities, research corpo- rations, and other ESSA components. Hydrological Models Considerable effort during the reporting period was devoted to the development and testing of conceptual hydrologic models which provide a continuous simulation of the streamflow hydrograph. The well-known Stanford Watershed Model is being tested for its applicability to operational forecasting. The Streamflow Synthesis and Res- ervoir Regulation (SSARR) Model, originally developed by the staff in the Corps of Engineers Office in Portland, Oreg., and used by the Portland RFC in operational forecasting for the Columbia River Basin, is also being tested. These Models are being tested on several river basins in the United States with widely varying climatic characteristics. Snow and Snowmelt Snow measurement and snowmelt problems received con- siderable attention by the Office of Hydrology during the last 2 years. In cooperation with the Department of Agri- cuhure's (DOA) Agricultural Research Service (ARS), the 60 metamorphosis of snow is being studied at the ARS Sleepers River Experimental Watershed in Vermont, with special attention being given to the energy budget for computing rates of snowmelt. A study has also been initiated at this site to determine effects of exposure on precipitation gage catch and to develop methods for obtaining "true" ground precipitation (especially of snow). Simulation studies of snow accumulation and ablation processes in conjunction with the Stanford Watershed Model are being made. Addi- tional test areas besides the Sleepers River Experimental Watershed include the Rock River Basin of Minnesota and Iowa, and several basins in the Rocky Mountain States. Evaporation The Hydrological Research and Development Laboratory has also been quite active in research efforts directed toward evaporation. At the request of the World Meteorological Organization (WMO), comparative studies have been made of evaporation instruments in use to assist in the selection of an interim international reference evaporimeter. Tests of an experimental insulated evaporation pan show promise of being superior to any evaporimeters now in use. This pan will also provide reliable daily estimates of incident all-wave radiation. The Laboratory is also cooperating with the Geological Survey in a study of evaporation from the Salton Sea in California. The observational phase of this project has been completed; the study is now in the data reduction stage. Radar Precipitation Analysis One of the most difficult problems confronting operational hydrologists is the determination of integrated values of various hydrologic parameters over fairly large areas. Extra- polation of point values can frequently lead to gross uncer- tainties if the parameters being estimated are not contin- uous in time and space, such as precipitation which occurs from thunderstorm or other convection activity. Radar is the ideal device for determining the where and when of rainfall. The National Severe Storms Laboratory (NSSL) at Norman, Okla., has developed a method which produces a digital representation of the radar image for direct input into a computer. The amount of precipitation is determined by relating the echo intensity to the pre- cipitation rate. Consequently, periodic radar scans can be added or integrated over the entire hydrologic range of the radar — about 100 nautical miles — to produce a time- depth-location estimate of rainfall in near real-time and in computer-compatible form. The system method records the echo intensity of each 1-mile increment of radial distance for each 2 degrees of azimuth. These 1,440 discrete obser- vations, representing one full sweep of the radar, are each integrated values of the radar response for the increment of area; they are recorded on magnetic tape almost instan- taneously and transmitted to a computer by data telephone and data links. A test conducted at Fort Worth, Tex., during the summer of 1969 proved the operational feasibility of such a sys- tem. Rainfall amounts computed from radar data were found useable for the river forecasting program, permitting the generation of river forecasts directly from radar in- formation. Additional tests using two or more radars are planned. From these extensive tests, improved and more sophisticated methods of relating radar echo intensities to precipitation rates should result. Some rather elaborate studies of radar attenuation were made at the RL's Gunbarrel Hill test site near Boulder, Colo., by the Wave Propagation Laboratory (WPL) . In these experiments, both vertical-pointing and horizontal ra- dars were used to examine rainfall intensities and distri- bution along an 11-kilometer path. Because precipitation rates are dependent upon the fall velocity of raindrops, the vertical-pointing radar should furnish an additional dimen- sion to radar study of rainfall. Additionally, because radar impulses of different wavelengths (frequencies) react dif- ferently to the same rainfall situation, multifrequency radars may be used in future investigations. The WPL is also involved in radar precipitation analysis through research projects to improve remote sensing capa- bilities to meet the environmental monitoring requirements of hydrologists and weather observers. The problems of evaluating the effects of meteorological events over sizeable areas will require the use of remote sensing devices. Progress toward that objective is underway. Other R&D Projects in Hydrology R&D funds are utilized to support contract research in hydrology, with certain funds having been transferred to the Systems Development Office (SDO) of the WB and to the Environmental Sciences Group (ESG) of the NESC to conduct hydrologic research. Other areas of in-house research being supported in SDO include the collection and retransmission of hydrologic data by geostationary satel- lite and development of a flash-flood alarm gage. Contracts for hydrologic research have been awarded to various universities and research corporations. Areas of contractual research include: (1) ground water influence on streamflow in mountainous areas; (2) snowmelt proc- ess modeling on a combined analog-digital computer; (3) snow fence use for shielding precipitation gages; (4) areal extent of snow cover in plains and mountainous areas by satellite; (5) electromagnetic sensor correlation study; (6) rainfall-runoff relationship study in the Fairbanks, Alaska, area; (7) evaporation feasibility studies; and (8) variability study of the unit hydrograph. Expansion of the Hydrology Program High on the priority list for expanded program develop- ment is the plan to use advanced technology in automation and communication to improve hydrologic data collection and relay by satellite, to reduce and transmit digitized radar data, and to employ airborne remote sensors. Another high priority item is the improvement and expansion of the RFCs. Continuing development of more sophisticated and better forecasting methods is necessary to make improved hydrological services available throughout the country. More detailed, frequent, accurate, and wider selection of forecast products will better serve the Nation. 5 EARTH DESCRIPTION, MAPPING, AND CHARTING The Earth Description, Mapping, and Charting activity embraces the disciplines of geodesy, geomagnetism, and seismology, and includes aeronautical charting and marine geophysics. Within ESSA, this activity is both a service function and the subject of research and development (R&D) programs pursued by the Coast and Geodetic Sur- vey (C&GS) and the Research Laboratories (RL). ESSA's service programs in geodesy are concerned with establishing and maintaining horizontal and vertical con- trol points, determined by means of surface, aerial, and satellite triangulation and photogrammetry. These pro- grams provide adequate knowledge of locations and bound- aries necessary for the conservation and development of natural resources, for such civil engineering and scien- tific projects as microwave communication and petroleum exploration, for the national mapping program, for projects of economic significance including the construction of inter- state highways, and for control requirements in urban de- velopment. ESSA's R&D program in geodesy includes the development of new technology in the fields of satellite and aerial triangulation, photogrammetry, long-range distance measurements, and land and marine gravity measurements. Service programs in geomagnetism support ESSA's ef- forts in the compilation and production of charts indicat- ing the distribution of strength and direction of the earth's magnetic field. Such programs provide geomagnetic data and information required for land surveying and forecast- ing of radio propagation conditions, and assist in the proc- essing, analysis, and dissemination of data. The R&D pro- grams in geomagnetism are designed to improve the capa- bility for both prediction of the geomagnetic field with its variations in space and time, and the achievement of a better understanding of the origin of these effects and their relationship to other phenomena of the physical en- vironment. To attain these goals, ESSA supports research to improve instruments and systems, to develop better meth- ods and procedures for improved data gathering and analysis, and to investigate the interrelationship between the magnetic field and other parameters. The data for these studies are obtained from magnetic observatories of the world, and from local observatories on land, at sea, by air- craft, and by satellites. The service programs in seismology are concerned with the impact of earthquakes on the Nation and with the ex- pansion of knowledge on the structure and physical prop- erties of the earth's crust and deep interior. It is a multifacet program, involving the operation of a seismic observatory network to record seismic waves transmitted through the earth; location and publication of earthquake hypocenters; collection, cataloging, and publication of earthquake dam- age and intensity data; operation of an accelerograph net- work to record strong earth motions in earthquake-source regions; operation of tiltmeters and strainmeters in earth- quake-prone regions; and the operation of a tsunami warn- ing system. To assist in the acquisition of seismic data and the distribution of seismic information to the public, ESSA maintains a World Data Center for Seismology and a Na- tional Earthquake Information Center (NEIC). The World Data Center for Seismology collects final seismic data from international seismographic observatories and disseminates them to requesting users. The NEIC attempts to increase public awareness of the nature and extent of earthquake hazards. The R&D program is oriented toward the design and development of new instruments and systems, de- velopment of new analytical techniques to obtain more accurate information about earthquake hypocenters and source mechanisms, development of accurate travel times of seismic waves, and a better understanding of the earth's structure and physical properties. An important phase of ESSA's R&D program is the study of economic and life hazards in earthquakes and the development of guidelines to minimize the impact of destructive earth- quakes. ESSA has responsibilities for the production and distri- bution of aeronautical charts and for the development of improved cartographic methods. The service program in aeronautical charting involves all operations required to produce and maintain the aeronautical charts needed for 61 62 air navigation in the United States and its possessions. ESSA's research program concentrates on the development of new and the improvement of existing cartographic tech- niques. This R&D activity includes the development of new production techniques and of new types of graphic display of information. The role of ESSA in marine geophysics is to gain a clearer understanding of the structure, nature, and evolu- tion of the ocean bottom and the ocean basin boundary. To meet these objectives, studies are instituted in different oceanic regions of the world. GEODESY Service Programs The primary objective of ESSA's geodetic program, which is performed by the C&GS, is the development of funda- mental horizontal and vertical control survey networks for the United States and its possessions. These geodetic net- works serve as the basis for all engineering surveys required for economic growth and provide homogeneous reference framework for all scientific projects which relate to exact distances and directions on the earth, accurate three-dimen- sional coordinates referenced to the center of mass of the earth, and ultraprecise reference systems for such geo- physical problems as crustal movement, continental drift, and space tracking. The development of these surveys includes the extension SUBSIDENCE • Oil • Water • Earthquake Prediction HIGHWAY ENGINEERING and subdivision of the loops of the networks, continuous maintenance of the survey markers which constitute the permanent monumentation of the networks, and improve- ment of the overall accuracies of the networks through con- nections to the worldwide geodetic satellite framework. Both the worldwide and continental geodetic satellite networks, combined with the precise transcontinental traverses, estab- lish a reference framework accurate to one part in a million with respect to points within the network and with respect to the center of mass of the earth. The photogrammetry program within ESSA provides support to the aeronautical charting, marine navigational charting, oceanographic, and geodetic programs. The Photo- grammetry Division, part of C&GS's Office of Geodesy and Photogrammetry, is directly responsible for planning, sched- uling, and executing all photogrammetric activities within the C&GS. Users of Data The users of geodetic data include Federal agencies, nu- merous public and private groups within each of the 50 States, counties, and municipalities. Engineers and scien- tists within these governmental units use the survey data directly for supplementary survey control or indirectly for photogrammetric operation support to large-scale mapping for topographic, taxation, utility planning, boundary de- marcation, and many other purposes. LONGLINE COMMUNICATION & UTILITIES DEFENSE • Missile Guidance & Tracking • Bridges • Highways • Subways GEODETIC CONTROL Horizontal & Vertical Control Networks LEGAL PROFESSION • Boundary Disputes •Taxation & Recordation MAP MAKING • Topographic • Aeronautical • Nautical CITY SURVEYS • Plane Coordinates • Redevelopment Planning RECLAMATION • Dams EXPLORATION GEOPHYSICS • Oil Fields CONTINENTAL SHELF Some applications of geodetic control. 63 Field Operations During the past 2 years, the C&GS operated six hori- zontal control survey parties and three vertical control par- ties, averaging about 20 men each. These units established 1,500 new permanently monumented and more than 1,200 intersected horizontal control points and determined the elevations for 6,000 new bench marks. In normal operating procedures, approximately 50 percent of the previously established points must be reoccupied. Thus, the total num- ber of geodetic points surveyed exceeded 15,000. Additional survey data from other Federal agencies and some State groups involved the location of more than 2,800 new points which were adjusted and added into the National Geodetic Network. To maintain the horizontal and vertical control networks comprised of more than 120,000 monumented triangulation stations and approximately 320,000 bench marks, 18 one- man C&GS field units systematically search for and inspect these marks for damage resulting from natural or manmade causes, install highly visible witness posts and signs, and update the descriptions on these survey marks. If a station mark is reported or found to be in danger of destruction, the station is relocated nearby. This preventive mainte- nance action saves the Federal Government hundreds of thousands of dollars. A triangulation station can be moved for less than 10 percent of the cost of reestablishing a de- stroyed station. The comparative cost of moving a bench mark is 25 percent of the basic cost of a new survey. Many States and some of the rapidly growing urban areas have sought ESSA's assistance in the establishment of more precise and closer spaced control. Surveys for the States of Rhode Island and Vermont; the cities of Houston, Tex., and Albuquerque, N. Mex.; and the counties of Monroe, N.Y., and Honolulu, Hawaii, were completed during the past 2 years. The State Highway Department of Rhode Island requested the C&GS to establish primary control throughout the en- tire State, with 2- to 5-mile spacing between points. The State of Vermont required a survey for the northern portions of the State; this work by the C&GS was co- ordinated with the Vermont Base Map Organization Com- mittee. The survey control is to be used for a large-scale photogrammetric mapping project of the entire State. A first-order, class I triangulation project was completed by the C&GS in cooperation with the city of Houston; the project interconnected other surveys and updated previously monumented poitits. The Middle Rio Grande Council of Governments in New Mexico asked the C&GS to provide a first-order, class I triangulation network for metropolitan Albuquerque and 3 adjacent counties, with spacing of 2 to 5 miles in the metropolitan area and 4 to 6 miles in the adjacent counties. A first-order, class I triangulation network, spaced at 2- to 5-mile intervals over all of Monroe County, was estab- lished by the C&GS. The State of Hawaii requested the C&GS to undertake a survey to establish a first-order, class I network triangula- tion over the entire island of Oahu. Precise Alinement Survey The C&GS was requested by the Air Force during the reporting period to establish a precise alinement survey as a reference for the high-speed sled track at HoUoman Air Force Base, N. Mex. Similar surveys were previously con- ducted in 1956-57 and 1962. This track, which is approxi- mately 35,600 feet in length, is in relatively flat desert terrain. Increased velocities and improved sleds make it necessary to reestablish the reference line and obtain the highest precision possible. A special type of triangulation network was designed which would provide the maximum strength for this precise alinement. To provide redundancy and maximum statistical evidence for accuracy, two iden- tical networks were measured. These networks, parallel to each other and to the track, were spaced about 82 and 100 feet, respectively, offset from the track. Final results show that the uncertainties of alinement throughout the full length are less than 3 millimeters. Crustal Movement Surveys An intensive program of monitoring slippage and strain accumulation along the San Andreas Fault of California was continued. Results show a continuing horizontal slip- page of a few millimeters per year along the Hayward Fault of California in the East Bay area, and only 1 to 2 centi- meters per year along the San Andreas Fault in the vicinity of Hollister and in the Salinas River Valley. The releveling program in the San Joaquin Valley defined the regions of maximum subsidence which during the past few years has been averaging almost 30 centimeters annually. The basic continental releveling program, designed to furnish information on the broad regional vertical move- ments associated with tectonic processes, continued. During the past 2-year period, more than 5,000 miles were releveled. High-Precision Transcontinental Traverse The C&GS initiated a program for the measurement of a High-Precision Transcontinental Traverse Network, criss- crossing the conterminous States in FY 62. The completed Network will consist of five primary north-south lines and three primary east-west lines, with extensions to connect the framework to geodetic satellite triangulation stations. This precise survey will provide a scaler line for the Worldwide Geometric Satellite Network; three other scalers on three different continents will also be used. The Transcontinental Traverse Network also will serve as a control framework for the basic triangulation nets. During FY 68 and FY 69, 3,675 kilometers (about 2,275 miles) were measured by C&GS survey parties and about 200 kilometers (about 135 miles) by the U.S. Army Topographic Command (USA- TOPOCOM) ; more than 50 percent of the eventual 22,000- kilometer (13,640-mile) network has been measured. Worldwide Geodetic Satellite Program The C&GS has been engaged in the worldwide, 44-station, Passive Geodetic Explorer Satellite (PAGEOS) geometric 64 network since July 1966. This network is part of the Na- tional Geodetic Satellite Program, established through the joint efforts of the National Aeronautics and Space Adminis- tration (NASA) and the Departments of Defense (DOD) and Commerce (DOC), and in cooperation with the Federal Republic of Germany, United Kingdom, Australia, and other nations on whose territories camera stations of the world network are located. This effort is the largest, most exten- sive, cooperative international geodetic program ever under- taken. At the beginning of FY 68, 13 BC-4 camera systems were engaged in the data acquisition phase of the program: four operated by the USATOPOCOM, seven by the C&GS, and one each by the United Kingdom and Germany. By the end of FY 69, five additional camera units had been added to assist in meeting the proposed completion date of June 1970: three BC-4's, one each operated by the C&GS, South Africa, and Germany, and two PC-1000's op- erated by the Air Force. An employee from the C&GS is attached to each team except those operated by USATOPO- COM. Overall technical responsibility for the program, which includes the task of maintaining all camera systems and establishing and maintaining accurate time at all loca- tions, is provided by the C&GS. Gravity and Astronomy The gravity field of the earth provides the alinement framework necessary for geodetic instruments; the figure of the earth is expressed in terms of the gravity potential at the surface and above. Measurements of the intensity and direction of the gravity field, using gravity meters and astronomic instruments, are applied in: (1) refinement of the horizontal and vertical control networks; (2) develop- ment and operation of inertial guidance and navigation sys- tems; and (3) studies of the earth's internal and crustal structure in connection with the search for underground resources and analysis of earthquake mechanisms. Land gravity surveys were conducted in the vicinity of Washington, D.C., to determine deflections of the vertical at the U.S. Naval Observatory and two C&GS astronomic observing sites. Area gravity coverage was extended by survey operations in central Oklahoma. Marine gravity surveys were made in the Gulf of Maine and along the Florida-Georgia coast, continuing surveys of the east coast Continental Shelf, and over a portion of Norton Sound on the Alaskan Continental Shelf. Several gravity tracklines were measured by C&GS ships in con- nection with various oceanographic projects; an under- water gravity survey was completed in the area west of Cape Flattery, Wash. Extensive profiles of the geoid made possible by recent gravimetric and astronomic surveys were completed in vari- ous regions of the United States. These geoidal profiles are important for figure-of-the-earth studies and are essen- tial to relate scale and orientation of the satellite triangula- tion system to a new North American Datum. Detailed maps of the geoid were compiled for New Mexico, Arizona, and the New England States. Two of the five latitude observatories of the International Polar Motion Service at Gaithersburg, Md., and Ukiah, Calif., were operated by C&GS throughout the 2-year re- porting period. These observatories provide up-to-date in- formation on the small movements of the earth's axis within the body of the earth. Characteristics of this polar wander- ing reflect the internal strength and constitution of the earth. The measured displacements of the pole are applied to corrections for precise astronomical observations, to studies of the variations in the rate of rotation of the earth, and to a more precise determination of UTl time — ^that is, universal time corrected for the mean position of the pole. Aerial Photography Two aircraft were used to obtain panchromatic, infrared, and color aerial photography with wide-angle and super- wide-angle single-lens, precision metric cameras. Two C&GS aerial photographic missions accomplished 60,000 kilom- eters of aerial photography during the reporting period. The primary areas of photographic interest were coastal areas and commercial airports. Special-purpose aerial pho- tography was obtained to provide tide-controlled infrared photography for the accurate location of the mean high- water line, and to use tide-controlled color photography at low water for the compilation of rocks, obstructions, and nearshore detail, and for the location of navigational aids and other features of importance to the mariner. Photogrammetric Operations Shoreline Mapping Parties — photogrammetric field sur- vey units of the C&GS — accomplished coastal mapping, chart maintenance, and tidal current survey projects along the Atlantic and Pacific coasts. These Parties provided photo- hydro support to those C&GS vessels and shore-based launch parties that were engaged in hydrographic operations, in- stalled and monitored tide staffs for tide-controlled infrared photography, recovered and premarked control before aerial photography, field-edited shoreline surveys and chart draw- ings, and inspected marine facilities for the preparation of Small-Craft and Intracoastal Waterways Charts. Aero Survey Parties were assigned to survey airports and locate aids to air navigation for the Federal Aviation Adminis- tration (FAA). Coastal Mapping The Photogrammetry Division's activities provided de- tailed mapping information for nautical chart construction and maintenance, conducted shoreline surveys and supple- mental control for hydrographic operations, furnished loca- tions of landmarks and aids to navigation, and supplied reductions of tidal current measurements. In the past 2 years, about 225 shoreline maps with specially prepared aerial photographs and related photogrammetric data were furnished to C&GS vessels for use in hydrographic oper- ations. For chart maintenance work, a total of 825 regular charts, Small-Craft Charts, and basic map drawings were corrected from new aerial photography. 65 Color photography was used for the photogrammetric location of over 1,200 aids to navigation; a similar num- ber of landmarks were located on map and chart drawings. Over 300 special Airport Obstruction Charts were com- piled and published for the FAA; included in the number were air navigational facility maps and noise abatement mosaics. Coastal Inundation Mapping Under a reimbursable agreement with the Department of Housing and Urban Development (HUD) made in May 1969, ESSA initiated a pilot project in coastal flood studies. This cooperative program effort involves the Photogram- metry Division of C&GS, other components of ESSA, and other Federal and local Government agencies. Flood stage information will be collected from tidal observations of the C&GS's Oceanography Division and from the archives of other agencies. The Weather Bureau's (WB) Office of Hydrology will furnish much of the hydrological and me- teorological analysis. Coastal inundation mapping and sur- veying, required for HUD's flood insurance studies, will be provided by the Photogrammetry Division. Coastal Boundary Surveys The State of Florida entered into a reimbursable agree- ment with C&GS during the latter half of FY 69 for the determination of tidal datum planes and for the mapping of both the mean low-water and high-water lines. The work will require 5 or 6 years, depending upon adequate fund- ing, and will involve the participation of the Geodesy, Ocean- ography, and Photogrammetry Divisions. Buffalo Aircraft During FY 69, Congress authorized ESSA to accept the transfer from NASA of a DeHavilland Buffalo DHC-5 air- plane for operational and research uses. The aircraft was extensively modified for aerial metric photography to sup- port the C&GS's mapping and charting services; the air- craft became fully operational during the spring of 1969 and saw service in the Southern States, Puerto Rico, and Alaska. Three mapping camera stations are equipped to permit simultaneous infrared, panchromatic, and color pho- tography; when desired, simultaneous photography at dif- ferent scales is possible by using normal-angle, wide-angle, and superwide-angle cameras. The three camera stations and operational capability of the aircraft are considerably superior to those available to the C&GS in the past. Supplemental Control by Analytical Aerotriangulation Analytical aerotriangulation permits the accurate deter- mination of the ground coordinates of objects appearing on a block of overlapping aerial photographs, using rela- tively few known ground positions. The digital calculation approach depends on comparator measurements of pertinent image positions on each photograph. This approach con- trasts with the analog approach where measurements are made with a stereoscopic plotting instrument. The analytical aerotriangulation photogrammetric system, referenced to the classical geodetic datum of the United States, has a statistical accuracy that range from less than 1 inch to 1, 2, or more feet, depending on the size of the uncontrolled area and the height of the photography. ESSA DeHavilland Buffalo DHC-5 aircraft supporting the C&GS's mapping and charti ng services. 66 Presently, it is technically and operationally feasible to determine photogrammetrically the geodetic positions and elevations of an unlimited number of objects on the ground with a root-mean-square accuracy of 3 feet for premarked points (6 feet for natural objects) in blocks of 5,000 square miles or larger, based on classical geodetic horizontal and vertical control only on the periphery of the area and to about a dozen points of known elevation scattered within the area. A comprehensive test of the analytical aerotriangulation system was conducted by the C&GS in an area of 2,100 square miles in Kansas; a root-mean-square error of 2 feet horizontally and vertically was obtained. A cooperative test conducted by the C&GS and the Geological Survey on a pilot project area of 1,600 square miles reported results with a horizontal error of 2.1 feet and a vertical error of 1.7 feet. During the last 2 years, extensive revisions and improve- ments were made to existing computer programs. The 180 Photograph Model Program developed for the STRETCH computer was revised and enlarged to accommodate blocks which might include 600 photographs for ESSA's on-line computer. Automatic Drafting Machine A Swiss automatic drafting machine installed at the C&GS in August 1968 has been successfully and economically used in limited operations. This drafting machine does automatic drafting and plotting directed by a small on-line computer using magnetic tape. Drafting can be either penciled, inked, or scribed lines by either linear, circular, or cubic inter- polation. The machine has great capability for plotting posi- tion data and will draft lines at speeds as great as 120 inches per minute to an accuracy of 0.03 millimeters. The drafting machine has been used to produce commonly used map projections, plots of geodetic and geophysical data, star charts for satellite geodesy use, bases for special-type charts, and cadastral survey plots. Manual of Color Aerial Photography The Photogrammetry Division of C&GS made significant contributions to a Manual of Color Aerial Photography pub- lished under the sponsorship of the American Society of Photogrammetry. This Manual was a cooperative effort in- volving contributions from professional photogrammetrists in the Government, universities, and industry. Research and Development Programs The R&D programs in geodesy within ESSA were con- ducted by both the Geodesy Division of C&GS and the Geo- detic Laboratory of RL until July 1, 1968; at that time, the Geodetic Laboratory was transferred to the C&GS as its Geodetic Research and Development Laboratory. This action collocated all satellite geodetic research with the operating geodetic program. Reporting of R&D projects was consolidated for the reporting period under C&GS. Trilateration Test Net A special trilateration study was conducted by the C&GS in cooperation with a Louisiana Department of Highways project. The network consisted of 19 primary points cover- ing an area of 500 square miles in the northwestern por- tion of the State. Two independent surveys were made — the first by conventional triangulation techniques, and the second by trilateration with all lines measured with the laser Geodimeter. A complete analysis of the two methods was made. Adjustments indicate that the standard error of position determination is much less by the trilateration technique, perhaps at a ratio of one to four. A final eval- uation will cover the economy of field operations, efficiency with which the measurements can be made, overall accuracy attained, and utility of the final adjusted data for further local extension of survey operations. Refractive Index of the Atmosphere Research has been performed on the improvement of techniques for the measurement of the refractive index of the atmosphere through which the Geodimeter measurements are made. One finding verified that when the difference of elevation of the end points of a line is large, but known accurately from connections to precise leveling, the refrac- tive index along the line may be determined by making simultaneous vertical angle measurements at the ends of the line, bracketing the time when Geodimeter measurements are made. The contribution of error or uncertainty for this effect has been reduced to much less than one part per mil- lion. The technique has given such satisfactory results that cost reductions were made by eliminating midpoint balloon temperature measurements and by reducing the total num- ber of Geodimeter measurements within the basic traverse figure. The Wave Propagation Laboratory (WPL) and the Insti- tute for Telecommunication Sciences (ITS) of ESSA's RL have developed distance-measuring instruments, using two optical wavelengths that automatically compensate for the atmospheric reflective index. Time Studies Timing is the single most important item in the data acquisition phase of the geometric satellite program. Unless all stations observing an event observe simultaneously with- in a few microseconds, the observations are useless. At the beginning of FY 68, time was maintained at field units by a hand-carried portable time standard sent to each field station every 6 weeks. The portable clock was cali- brated before and after each trip at the U.S. Naval Observa- tory in Washington, D.C. A new method for transferring time by two-way radio transmission through synchronized-orbiting satellites — ^Ap- plications Technology Satellites (ATS) 1 and 3 — was de- veloped by C&GS and the National Bureau of Standards (NBS). This method was used whenever remote stations could see one of the satellites. The results are accurate to at least ± 10 microseconds. The use of long-range aid to navigation — Loran-C — radio broadcasts was pursued, with equipment and proce- 67 dures developed to satisfy program needs. As Loran-C chains around the world became synchronized, this method proved usable to accuracies of ± 10 microseconds. Timing was being controlled at seven sites by this method by the end of FY 69. Development of a system to transfer time by means of satellite-borne clocks in a polar orbit was also initiated during the reporting period. This system was particularly needed for isolated Antarctic stations where no other timing clock types were possible. This method, the Satellite Time Recovery System (STRS), provides an accuracy that is better than 50 microseconds. were modified; the plates previously measured were sched- uled for remeasurement. Satellite and Terrestrial Gravity Combined Special investigations have been made by the C&GS to combine satellite and terrestrial gravity data for a more exact determination of the geopotential. Instead of using the expansion in spherical harmonics, the geopotential is represented by a simple layer distributed over the surface of the earth. Existing gravity anomalies are combined with density values of this surface layer as determined from Baker-Nunn camera observations. Reduction of Satellite Data Intensive research has been conducted by the C&GS in the analysis of all types of errors associated with the reduction of geodetic satellite data. A statistical comparison of residuals from the mathematical adjustment of the com- parator measurements of star and satellite images on photo- graphic plates revealed a systematic bias related to the time of day when the measurements were made and probably related to thermal-loading effects within the comparator. A review of the design of the Mann Comparator disclosed that the plane of the measuring mark, being close to the viewing system, is about 6-centimeter distant from the plane of the photograph being measured. A structural change was made to project optically the measuring mark onto the plane of the photograph. This systematic bias was of the order of 0.3 or 0.4 microns, or equivalent to about one part in a million. Six comparators used in the program New^ Adjustment of the North American Datum One of the major problems confronting geodesists for many years is the requirement for an eventual readjust- ment of the horizontal control networks of North America. With the availability of the Worldwide Geometric Satellite and the High-Precision Transcontinental Traverse Networks, an eventual long-range readjustment program is being planned. Because the fundamental mathematical approach to the task differs greatly from any prior adjustment, the project requires the adjustment of new measurements of much higher precision, rather than a revision of the older classical triangulation networks. ESSA has requested the Division of Earth Sciences of the National Research Council (NRC), National Academy of Sciences and National Academy of Engineering (NAS/ NAE), to make a feasibility study of this adjustment prob- lem; a panel was selected and a published report is expected in FY 70. Artist's conception of the extension of the North American triangulation network to Hawaii by means of geometric satellite geodesy. 68 GEOMAGNETISM Service Programs ESSA, through its C&GS component, operates 14 standard magnetic observatories in the United States, Puerto Rico, Guam, and the Antarctic to obtain records of long- and short-term changes in the intensity and direction of the earth's magnetic fields. A fifteenth observatory. Plateau Antarctica, was discontinued as planned after 3 years of operation. All observatories are funded by ESSA except for the two in Antarctica funded by the National Science Foundation (NSF) . Each observatory continuously monitors the fluctuation in the earth's local magnetic field. Similar data are obtained for other parts of the world by approxi- mately 175 observatories; these magnetic data are exchanged between countries. Additional basic research describing the distribution of the earth's magnetic field in time and space to identify sources and variations in strength of the magnetic field was undertaken by the Earth Sciences Laboratories (ESL) of RL during the past 2 years. At frequent intervals, magnetic data are used to update regional and world magnetic charts which determine cor- rection factors to apply to magnetic field measurements made by land, marine, and airborne magnetic survey parties. The magnetic data are in continuous demand to support studies in atmospheric physics (including the forecasting of radio propagation conditions), in electrical conductivity and composition of the core and mantle of the earth, in monitoring of solar activity, and in mapping of the earth's space environment. Magnetic declination (angular difference between true north and magnetic north) is indicated on all nautical and aeronautical navigation charts. Correct charting of long- term changes in magnetic declination or variation and in other magnetic elements requires additional magnetic meas- urements made by C&GS geomagnetic field units at about 175 carefully selected and permanently marked survey points throughout the United States; these points or repeat stations are checked at 3- to 5-year intervals. Besides repeat surveys, these geomagnetic field units conduct special surveys to satisfy a particular user's request. For instance, a highly detailed survey of a particular loca- tion may be made to determine whether the location is free from the contaminating influence of local magnetic materials. To obtain data over the deep oceans and continental shelves, marine geomagnetic surveys are conducted. During the past 2 years, the C&GS prepared a systems analysis of marine geomagnetism to identify applications of marine magnetic data and to make data acquisition and software recommendations. A significant effort was also directed to- ward the compilation and identification of backlogged marine geomagnetic data. A marine geophysical mapping survey of a portion of the Alaskan Continental Shelf began during the reporting period. Coil system and sensor for the rubidium magnetometer used in ESSA's Automatic Standard Magnetic Observatory. Magnetic Analysis Analyses of magnetic data from field work and observa- tories — including quality control and evaluation, assignment and application of calibration factors, and evaluation of results for accuracy — are performed to produce high quality data for integral use in magnetic and navigational chart production activities and for the needs of modern science and technology. The purpose of these analyses is to provide information and services to users requiring both static and dynamic descriptions of the earth's magnetic field. Analog data are converted to digital form for use in machine data-handling systems, with output deposited in the World Data Center for Geomagnetism at Rockville, Md., to facilitate broad dissemination. Information Services As part of its geomagnetic program, the C&GS prepares magnetic charts of the United States and of the entire world. Each chart series depicts one of five magnetic field elements — declination (or variation), inclination, horizontal inten- sity, vertical intensity, and total (scalar) intensity — and the distribution of its annual change rate. Declination charts are recompiled at 5-year intervals to reflect the acquisition of additional data during the interval since the last chart was issued and the effects of long-term secular changes; other charts in the regular series are pro- duced at 10-year intervals. The last complete revision of the regular magnetic chart series was in 1965; preparations are underway for issuance of the 1970 charts in early 1970. Special charts (for example, declination charts of Central and South America and of the Great Lakes of North Amer- ica) are prepared on contract as required. Isogriv charts which relate magnetic directions to rectangular navigation grids in the north and south polar regions are also compiled. 69 f Geophysicist adjusting light sources of S-component rapid-run magnetograph at the Fredericksburg Geo- magnetic Center, Corbin, Va. Magnetogram scaling machine used to convert analog recordings into digital values. 70 Research and Development Programs One of the missions of ESSA is to chart and to monitor the earth's magnetic field, its changes, and its intensity across the United States and throughout the world. These data — the basic magnetic field and its secular and transient changes — are required for all types of navigation, for geo- physical prospecting of mineral resources, and for scientific studies of the earth's crust and tectonic change within the earth. Magnetic data are also vital to the mapping of the space environment, including the belts of trapped radiation girding the earth and the complex interplay of solar and terrestrial fields and plasmas. Geophysicists at Boulder, Colo., and Rockville are working to perfect both mathe- matical and physical models of the sources of the earth's magnetic field and its change with time. Mathematical Magnetic Models The Geophysics Research Group of the Office of Seismol- ogy and Geomagnetism in the C&GS conducted various projects to obtain mathematical descriptions of the main geomagnetic field and its secular change, and to study the faster temporal variations of the field, including those re- sulting from the action of the equatorial electrojet. Mathe- matical descriptions were used to compile charts of the main field and its annual change by computerized methods. The temporal variations study gave information for adjust- ing the main field to epoch. A mathematical model of secular change for the interval 1960 to 1965 was developed; an improved model was sought by a better analytical method for using the data. Another study by the Geophysics Research Group con- cerned the mathematical descriptions of the main geomag- netic field, its secular variation resulting from current sys- tems in the earth's core, and with faster temporal fluctua- tions resulting from current systems in the ionosphere, magnetosphere, and magnetosheath. Mathematical models were developed by spherical harmonic analysis and were in the form of polynomials or Fourier series. A mathematical model of secular change covering the interval 1900 to 1965 was developed; an evaluation of the model was initiated during the reporting period. The Geomagnetism Division of the Office of Seismology and Geomagnetism investigated the properties and inter- conversion of low-order model fields, such as dipole and quadrupole models, centered and eccentric. From this study it is anticipated that techniques can be developed to manip- ulate more complex models and fit them to survey results. Pertinent trigonometric functions were manipulated alge- braically; geometric insights including compounding, reso- lution, and the equivalence of different modes were devel- oped. Work was also done on eccentric dipoles. This study also involved an investigation into the equatorial electrojet by means of bays and similar short-term disturbances. Records taken at equatorial stations were searched for per- tinent events, and scalings were made and studied. Paleomagnetism A detailed search was instigated during FY 69 into geo- magnetic data archives to uncover data permitting harmonic analysis of the magnetic field for the period 1725—1965; such information is important in determining whether a reversal tendency of the earth's field is possible. The ESL began new work in paleomagnetism with the aim of com- piling a detailed history of reversals in the earth's field; this work forms the basis for interpreting the implications of the current trend of decrease in the strength of the field. Paleomagnetism contains many uncertainties and assump- tions relating to underlying field reversals. Most prior geo- magnetic research has emphasized declination and inclina- tion measurements, and not intensity measurements. Present- ly, the emphasis is upon intensity measurements before, during, and after a particular reversal through application of new techniques for controlling the atmosphere surround- ing the rock inside a furnace, enabling the re-creation of the theoretical environment of the rock at the time of its formation. The past Fiscal Year has seen the near comple- tion of the construction and testing of measurement systems and facilities that are necessary for paleomagnetic research efforts. Hydromagnetism and Earth's Core The ESL also initiated a theoretical study of the hydro- dynamics of the earth's core and its relationship to the ob- served magnetic field. The amplification equation of hydro- magnetism and the vorticity transport equation, obtained from the Navier-Stokes equation, yielded the requisite simultaneous differential equations describing fluid velocity and magnetic induction in the core. Studies of long-term secular changes derived from his- torical studies of reversals mentioned above suggest the possibility of determining fluid motion in the upper 200 or 300 kilometers of the core. Sources of Earth's Magnetic Field Results from a model study of sources of the earth's field in FY 68 indicated that the observed field can be accounted for by a centered dipole and 19-radial dipole sources placed at 0.136 earth's radius from the center. During FY 69, suc- cess was achieved by ESL scientists in adjusting dipole parameters for 21 dipoles to fit the 1955 Finch-Leaton field of the earth to a root mean square of only 28 gammas. The dipole parameters were then adjusted to fit the secular change for the 1955 Finch-Leaton field to a root-mean-square value of 2.125 gammas per year in the vertical component. This adjustment showed the typical westward drift of ap- proximately 0.15 degrees per year. Work was started for a similar fit to the field and secular change for the new International Geomagnetic Reference Field determined by the International Association of Geomagnetism and Aeron- omy (lAGA). Continuing observations of variations in the absolute geomagnetic field increasingly demonstrated the immediate 71 need for an accurate, sensitive, and stable magnetometer. An increase in geomagnetic measurement accuracy brings with it the resolution of major questions regarding the physics of the origin of natural phenomena. Because of ESSA's ex- tensive involvement in a wide variety of geomagnetic ob- servations about the world, the ESL scientists continue the development of new, relevant, and refined instrumentation. During FY 69, a single-line rubidium magnetometer was developed by the ESL. Construction was also completed on a second system. Simultaneous operation of these two sys- tems will establish their accuracy, sensitivity, and stability. Once initial short-term tests have been completed, ESL will operate these two systems at varying separations to define the extent of spatial uniformity of magnetic field variations. These data will serve to describe the nature of the source of the field's variations and the induction effects associated with the areas of study, and will permit more accurate investigations of geopiezomagnetic variations. Magnetic Spatial Noise The ESL scientists conducted magnetic spatial-noise studies at the Craters of the Moon National Monument, Idaho; Lava Beds National Monument, Calif.; and Hawaii Volcanoes National Park, Hawaii. These studies involved the analysis of magnetic data in both space and wave- number domains to determine what limitations are placed on the detectability of signals at these high-noise sites. Such data are useful in developing techniques to permit magnetic instrument searches for lava tubes — caverns that could be used for shelter or storage and which, in certain semiarid areas, are the only water reservoirs. Additionally, spatial studies conducted on Hawaiian lava flows have shown distinct properties which could be related to the geological structure. Geopiezomagnetism ESL's studies in geopiezomagnetics, or geological magne- tism, encompass problems relating to the distribution and recent changes of the earth's crustal magnetic material. Ap- plications of such studies vary in the extreme range from sensing geological stresses preceding earthquakes to the discovery of moon-surface lava caves for astronaut housing. By taking advantage of a lowering of the water level of the lake — Franklin D. Roosevelt Lake — behind Grand Coulee Dam in Washington, ESL scientists are investigating the magnetic effect of a known stress by a nonmagnetic load on the geological structure. This particular investigation may establish the boundaries on the magnitude of the piezomagnetic effects detectable in the field with presently available instrumentation. After a reconnaissance trip in 1968, the investigation began with a second field expedition in 1969. During this latter expedition, 36 fixed observation points were established at varying distances as far as 10 kilometers from Roosevelt Lake. Magnetic observations were made at each of these points while the Lake was at its high- est level. During a third trip, also in 1969, the stations were reoccupied while the Lake was at its lowest level. Plans are underway for reoccupation of these stations during the summer of 1970 when the Lake is again full. SEISMOLOGY Service Programs ESSA, through its C&GS component, operates and main- tains a network of 20 seismological observatories in the United States and its possessions, and assists in the opera- tion and maintenance of a network of 16 cooperative seismo- logical stations that are under the guidance of universities, research institutes, or other Government agencies. These seis- mological facilities furnish basic data on earthquakes oc- curring throughout the world, and are particularly important for the data provided on U.S. earthquakes that have a direct effect on lives and property. Data are obtained from specialized instruments which monitor and record vibrations in the earth caused by earth- quakes and large manmade disturbances. By analyzing these seismic traces (seismograms) , seismologists are able to detect, identify, and locate earthquakes; determine earth- quake magnitudes; better understand the nature of the earth's crust, mantle, and core; and map seismic risk areas accurately. Similar data for many parts of the world ob- tained through exchanges with other nations are utilized to support the above analyses. Engineering Seismology Engineering seismology in the Office of Seismology and Geomagnetism of the C&GS involves the study of earthquake occurrences and their effects on manmade works. Activities in this field provide the engineer and the construction in- dustry with essential information — description of ground and building motions resulting from earthquakes — for the design of the earthquake-resistant structures. In regions of strong earthquake activity, specially con- structed seismographs are placed within a wide variety of structures and upon various types of soil and rock forma- tions to record earthquake motions. These instruments, inoperative until triggered by an earthquake, record the acceleration, velocity, and displacement caused by earth- quake-induced motions at the site. Through broad geo- graphic and geologic spacing of these seismographs, a wide range of response to motions is determined from different types of soil and geologic foundation materials; of couplings between the foundation and structures; and of the earth's structures themselves when subjected to a spectrum of earthquake vibration. Earthquake data are being used by the C&GS to produce seismic probability maps which aid local officials in the formulation of their building codes and assist architects and engineers in the design of earthquake-resistant struc- tures. 72 Damage resulting from landslide caused by a severe earthquake. At the end of the reporting period, the C&GS maintained 341 strong-motion seismographs in nine States and eight instruments in each of eight Central and South American countries. Approximately 100 of these instruments are owned by ESSA; the rest are owned privately and maintained cooperatively. An additional 368 seismoscopes which meas- ure only the maximum acceleration are installed and main- tained in west coast locations by the C&GS Seismological Field Survey in San Francisco, Calif. Earthquake Investigations ESSA, through the Seismology Division of the C&GS's Office of Seismology and Geomagnetism, serves as the global compilation center for a worldwide service program through which 300 countries and territories submit tele- graphic and airmailed reports of earthquakes recorded at their observatories. Data from these reports are fed into a high-speed computer from which earthquake hypocenter determinations are returned. The hypocenters provide basic data for seismic reports; such reports are being sent experi- mentally over international meteorological telecommunica- tion circuits to improve their timeliness. Since 1961, data from over 35,000 computed hypocenters are on punched cards at ESSA. Such cards provide answers to requests for information and data for automatic plotting of seismic histories. Since 1968, the Environmental Data Service (EDS) component of ESSA has assisted the C&GS by distributing these cards to subscribers. The National Earthquake Information Center (NEIC), located in Rockville, Md., was established in 1966 to dis- seminate seismic information to technical and public users. The NEIC has located over 150 large magnitude earthquakes within 2 hours of their occurrence, providing a fast service useful as guidance for aftershock studies and disaster relief efforts. 73 Pacific Tsunami Warning System The Pacific Tsunami Warning System operated by ESSA's C&GS provides warnings of the approach of a tsunami (seismic sea wave) to inhabitants living anywhere within the Pacific Basin. The National Tsunami Warning Center, the control center for the Pacific Tsunami Warning System, is also operated by the C&GS and is located at Honolulu, Hawaii. Data are collected and warnings disseminated through cooperative arrangements with countries and terri- tories bordering the Pacific Ocean. The first indication of the possible generation of a tsunami is the recording of an underwater or coastal earthquake by one of 20 cooperating seismograph stations (eight of these seismograph stations are operated by C&GS personnel; the remaining 12 stations are operated by cooperating institu- tions and foreign Governments) located within the Pacific Ocean Basin; an alert is then flashed to the Honolulu Control Center. After the Honolulu Control Center deter- mines that a possible tsunami-generating earthquake has occurred, tide stations are alerted to report the occurrence of actual waves; those tide stations nearest the earthquake epicenter provide the first confirmation. Upon confirmation of a tsunami, a warning is issued by the Honolulu Control Center to all countries and territories participating in the Pacific Tsunami Warning System. Communications are accomplished through the Federal Aviation Administration (FAA), the National Aeronautics and Space Administration (NASA), and the Department of Defense (DOD) facilities to avoid duplication of effort. Civil Defense, local law enforcement agencies, and military units disseminate warnings to the American public. Par- ticipating agencies of other countries are responsible for arranging communications between their agency and the nearest U.S. communications facility and for providing dis- semination to their local population. In addition to the National Tsunami Warning Center at Honolulu, the C&GS operates a Regional and two local warning systems in Alaska. The Regional Tsunami Warning System in that State is located at the Palmer Observatory, and the local systems are at the Adak and Sitka Observa- tories. Local facilities are responsible for issuing warnings to the public of nearby tsunamis. The Palmer Regional Center issues warnings to the entire State on all tsunamis threatening the Alaskan coast. These warnings are issued after prompt analyses are made of the seismic data recorded at the Palmer Observatory and its two satellite stations, together with seismic and tide data telemetered to the Palmer Regional Center from four seismological observa- tories and eight tide stations in the State. A regional system was under development in the State of Hawaii during the reporting period; it will become opera- tional in mid-1970. This new experimental warning system for locally generated tsunamis will consist of five seismic stations (one on the Island of Maui and four on the Island of Hawaii) and two hydraulic stations (on the Island of Hawaii) to record any possible tsunamis. Data from these stations will be telemetered by radio to the Honolulu Observatory for rapid analyses and early warnings to threatened coastal regions of the State. Additionally, ESSA operates the World Data Center for Tsunamis. Research and Development Programs The R&D programs in seismology within the C&GS are concentrated in the Seismology Division and the C^ophysics Research Group, and are directed toward improved under- standing of the natural forces generating earthquakes, of the mechanics of earthquakes, and of ways to quantify the earthquake hazard potential in given regions. Information derived from these studies has direct application to the ultimate development of a prediction system for earthquakes and tsunamis and to the design and engineering of earth- quake-resistant structures. Withing the RL, the bulk of the seismological effort is concentrated in the Earth Sciences Laboratories (ESL), with most of the seismic research in ESL's Earthquake Mechanism Laboratory (EML). The ESL's seismology re- search program involves: (1) detection of movements and monitoring of geophysical parameters along active faults; (2) special area studies; (3) investigation of the effects of earthquakes; (4) interpretive and analytical studies related to earthquake mechanisms; and (5) studies of the propaga- tion of seismic energy through the earth and the relation of propagation characteristics to global tectonics. Earth Structure and Earthquake Mechanisms Research which extends and clarifies knowledge on the physical structure of the earth and the physical mechanisms of earthquakes is aimed at acquiring basic information for possible use in earthquake prediction. Instruments are de- ployed in locations of known seismic activity to monitor all geophysical phenomena at the site. Analyses of the seismic data received at these sites reveal correlations be- tween the earth's physical or dynamical properties and the accumulation and release of elastic strains associated with earthquake occurrences. Such correlations might enable seismologists to establish premonitory phenomena which could give warnings of impending, potentially destructive earthquakes. Significant information about earthquakes and their processes is obtained by analyzing seismic waves recorded at C&GS and cooperative seismological observatories. Data obtained are used to determine the geographical locations of earthquakes, their focal depths, their magnitudes, their energy propagation patterns, and details of the earthquake process itself. Seismic waves provide a major source of information about the structure and composition of the earth's interior, furnishing valuable data to other geophysi- cal disciplines. Research studies involve the development and use of local, regional, and teleseismic tables, and their automatic data processing application. These studies are fundamental to geophysics because of their contributions to knowledge on the internal constitution of the earth and 74 Seismologist's concept of the interior structure of the earth. Graphical method for locating earthquakes in- volving the determination of distance from seismograph station to the earthquake source. 75 its present dynamics; such studies are also important to the fields of engineering seismology and tsunami generation. Efforts are being made to increase the value of the seismic wave records by improving recording instrumentation, by increasing earthquake location determination accuracy, and by developing more advanced data processing capabilities to include larger quantities of data in the analysis. The University of California Seismographic Station at Berkeley and the EML have cooperated in an experiment to record seismic waves along a profile from the east slope of the Sierra Nevadas to San Francisco Bay, using as energy sources the BOXCAR and BENHAM events — high-yield nuclear explosions detonated under Pahute Mesa in Nevada. A line of stations was established along the azimuth from the east slope source area in eastern California at Mam- moth Ski Lodge to San Francisco Bay and beyond to the Lamont-Doherty Geological Observatory's Ocean Bottom Station off Point Arena, Calif. An essential element in analysis and interpretation of seismic signals is knowledge of the geology and seismic background characterictics of both the areas of seismic activity (natural and manmade) and the areas where de- tection instruments are located. The portable seismic instru- ments developed by the EML as part of its Data Acquisition and Analysis (DACAN) System provide the means by which the needed information can be obtained. A large seismic array in Norway is expected to enhance greatly the capability of seismologists to detect and identify small seismic events. During FY 69, important preliminary tests and calibrations were performed on the new array by EML research groups. The EML developed and built six systems to make its DACAN units compatible with the Large Aperture Seismic Array (LASA) sensors, and tested these systems at the LASA-Montana facility near Billings, Mont. Personnel from EML accompanied the five DACAN portable seismic recording systems to Norway for field experiments. The field experiments attempted to answer whether a notice- able amount of seismic information was gained by recording at the bottom of the 60-meter wells at the Norway site, and to determine at what distance from the sensors did micro- seisms become incoherent at the site. Specific field tests were made to determine amplifier (LASA and DACAN) and seismometer frequency response and gain, and amplifier data-line tape recorder system noise. Other field recordings of particular interest were earth-noise at 7-hour intervals, earthquakes heard on an audiomonitor, and cultural noise heard on an audiomonitor. Selected portions of the field data recorded in analog form have been converted to digital form. Some preliminary analysis was done in time to sup- plement the work in the field by using the Sandia Corpora- tion computer facilities at Livermore, Calif. The field ex- periment has been completed and data analysis is in progress. Field operations on a reimbursable project were con- ducted in the Northern Territory of Australia during the summer of 1967. The objectives of the overseas operations were to describe the parameters of recorded microseisms and the seismic signal reception. Seismic noise recorded in Australia is 3 to 20 decibels higher (at 1 Hertz) than at a Vernal, Utah, site. The detection threshold of seismic events in the Northern Territory of Australia is slightly higher than in Utah for shallow events. The amplitude of micro- seismic activity shows a correlation with meteorological activity. Many shallow seismic events recorded displayed anomalously short periods. At present, most hypocenter determinations are accurate to within 25 kilometers of the true position, while a few are only accurate to within 50 to 100 kilometers. When assign- ing zones of seismic risk to a region, knowledge of which faults in a complicated system are active is important. Most faults are buried, and usually earthquakes leave no surface evidence. ■ Consequently, the only way to identify active faults is to locate epicenters accurately. Identification of ac- tive faults will improve the accuracy of risk zoning, eliminate uncertainties, and increase public confidence. Tsunamis are generate^ by shallow focus earthquakes that occur at certain positions with respect to the sea floor. Shocks with deep foci or those that occur inland do not cause tsunamis. Some of the regions where the most disas- trous tsunamis have originated are the very regions where location accuracy is the worst; for example, in the Aleutian Islands and along the western coast of South America. Im- proved location accuracy will reduce the false-alarm rate of the Pacific Tsunami Warning System and lower its cost, but more importantly will increase public confidence in the System. The C&GS investigated methods for incorporating local and regional source and station corrections into standard travel times to increase the accuracy of hypocenters. This effort is complicated by highly complex regional crustal and upper mantle anomalies and by lateral inhomogeneities in the lower mantle. A detailed study of P- and S-travel times and station corrections for Japanese earthquakes was com- pleted, and travel times for multiply-reflected core waves were also computed. More sophisticated methods for locating earthquakes were investigated by the C&GS. The objective was to eliminate automatically those spurious readings which fall outside the expected region of error. This work was done in cooperation with the International Seismological Centre in Edinburgh, Scotland, and has resulted in programs which produce accurate locations with little human attendance. ESSA scientists worked with personnel from the Lamont- Doherty Geological Observatory on studies of earthquake epicenters and mechanisms, using data obtained from the Worldwide Network of Standard Seismograph Stations. From these data, they were able to develop a new com- prehensive global tectonics model and to determine its re- lation to sea-floor spreading and continental drift. Two ESL studies pertinent to earthquake mechanism solutions neared completion during FY 69. In the first study, solutions for deep- and intermediate-depth earthquakes were investigated on a worldwide basis in an attempt to study the distribution of stress within descending plates of litho- sphere as postulated in the new global tectonics. The results support the hypothesis that plates of lithosphere sink into 76 Seismograph instrument stations used in Worldwide Network of Standard Seismograph Stations. the asthenosphere as a result of body forces on excess mass within the plates and "hit bottom" beneath the asthenos- phere. In the second study, focal mechanism solutions were obtained in a regional study of western South America. These included the largest earthquakes that occurred dur- ing the 7-year interval — 1962-68. Research activities are also being directed toward the following: First, development of data processing techniques, including new theoretical considerations and more sophisti- cated mathematical methods, for use in locating earth- quake hypocenters is underway. Studies in travel times of seismic waves and their relation to earth structures, using advanced wave theory, are being made. Second, in- vestigations of new P-surface-focus travel times to derive a velocity model of the earth are in process. Third, inter- pretation of seismological data from networks of stations, located in Nevada and the Aleutian Islands of Alaska, which monitor regional seismicity and seismic effects of nuclear explosions is continuing. These data are expected to extend knowledge of earthquake mechanism, earthquake prediction, and relationship of earthquakes to regional structure. Strain and Creep Measurements The ESL conduct basic research designed to improve understanding of the physics of earthquakes. A specific lab- oratory of the ESL— the Earthquake Mechanism Laboratory, located in San Francisco — investigates seismic events. During the reporting period, the EML intensified its strain and creep measurements along the San Andreas Fault of California, the principal observational site for earth- quake research. Cooperative research work with Stanford University in FY 68 uncovered nearly a dozen examples of magnetic signals preceding creep events on the San An- dreas Fault. Steps were taken to monitor both the telluric current and magnetic fields. 77 Piezomagnetic effects associated with the San Andreas Fault are being studied. Stanford University supported by an ESL grant operates an array of optically pumped Ru- bidium vapor magnetometers to observe the possible mag- netic effects from tetonic stresses associated with earth- quakes and creep events. Investigations show that some creep events are preceded by magnetic precursors. Limited laboratory experiments at Stanford and elsewhere have shown that the electrical resistivity of rocks is also stress- dependent. The objective of ESL in monitoring geophysical phe- nomena on fault zones is to measure, continually or pe- riodically with the greatest possible sensitivity, all possible indicators which might foretell an earthquake. This ob- jective represents an empirical approach in the absence of confirmed theories for the mechanism of earthquakes. A variety of techniques are being employed in fault moni- toring. The EML has established an important geophysical monitoring facility at Stone Canyon near Hollister, Calif. Creep-measuring stations have been established at approxi- mately 30 points along the San Andreas Fault. Fourteen places along the San Andreas and other Faults in California are equipped with 25 Invar-rod creepmeter units. Even though the installation of creepmeters is only par- tially complete, some worthwhile data have already been ob- tained. Analysis of these data has delineated the occur- rence of fault creep on the San Andreas, Hayward, and Cala- veras Faults. Preliminary analysis of the measurements shows that the time character of fault creep varies con- siderably from one site to another, even at sites within tens of kilometers of one another and on the same fault. The creep appears to be eventful at some places, and con- tinuous at others. Creep events measured at two sites on the San Andreas Fault suggest a rate of creep propagation on the order of 10 kilometers per day. Another aspect of the long-range fault creep monitoring program involves the periodic measurement of a series of survey lines. These resurveys detect movement in the im- mediate vicinity of the faults. Creep survey-line sites were established along the Hayward Fault in Oakland, Hayward, and Fremont, Calif. The EML completed the configuration and design of a new Telemetering Seismometer System field terminal, making the first installation near Watsonville, Calif. Cooperative work with the Colorado School of Mines revealed evidence of extremely large strain rates near the Rocky Mountain Arsenal's deep disposal well near Denver, Colo. These rates were studied to find their time relationship to damaging earthquakes. In a cooperative project involving RL's EML, the C&GS, and Colorado School of Mines, two quartz-bar strainmeters were entrenched north of Beatty, Nev., to observe the BENHAM underground nuclear event of December 19, 1968. These instruments, oriented approximately radially to the source, were located at distances of 28 and 71 kilo- meters from ground zero. A most significant observation was that the strain step from the BENHAM event apparently decayed to near zero within one-half of an hour, whereas earthquake steps do not decay within several days, if at all. This decay with time appeared to be a reflection of the pres- sure history of the cavity. To increase the effectiveness of information flow, the EML was connected to a timesharing computer service in FY 68. This computer service is a multiplex-telemetering sys- tem designed to carry six channels of strain, creep, or tilt data over one telemetry channel in time sequence. At the San Francisco receving end, the system separates each channel into its proper visual display for recording. Engineering Seismology The aim of the C&GS's R&D program in engineering seis- mology is to reduce loss of life and property resulting from earthquakes by developing information for regional, urban, industrial, and land use planning, by providing earthquake- motion criteria for the design of earthquake-resistant struc- tures, and by supplying data to Federal, State, and local governmental agencies concerned with relieving the impact of natural disasters. Research in engineering seismology has been planned in conjunction with operational programs in seismology to maximize scientific output from the operational programs. Anticipated benefits of these research efforts are: (1) seis- mic risk maps to permit the most efficient use of available land consistent with the seismic hazard; and (2) improve- ment of engineering design principles for earthquake-resist- ant structures, based upon research studies of the nature of earthquake strong motion. In keeping with these aforementioned goals, the C&GS conducted a study to develop criteria helpful for evaluating earthquake hazards and to present the results in a form useful for seismic design of building structures. The Geo- physics Research Group of the C&GS prepared and issued a seismic risk map, taking into consideration the geographic locations of earthquakes, geological and soil conditions, population densities, and construction types. This map has been accepted for use in the 1970 edition of the Uniform Building Code. During FY 69, the Group also modeled the economic losses resulting from earthquake damage to single- family dwellings in California for a maximum credible earthquake and for all earthquakes in California during the past 157 years. For this study, a construction-type sampling survey was made; census data and construction reports provided numbers of units, and structural engineer- ing experts determined housing element failures. Theo- retical isoseismal maps were constructed for each event, assigning damage intensities to unitized geographical areas; losses for each geographic area were then calculated and summed. The C&GS, in cooperation with the California Institute of Technology, digitized strong-motion seismograms and compiled a data bank of seismograms for engineering studies. Amplitude spectra of these digitized events were calculated to obtain relative ground motion, a factor related to soil and geological conditions; in an engineering context, ground motion becomes important in soil-structure inter- action. 78 Inputs into this R&D program include intensity data from damage surveys following destructive earthquakes and strong-motion data from instrumental recordings of earth- quake-induced motions on various types of surface geology. The data obtained are analyzed to evaluate the relationship between recorded motion and structure damage, the in- fluence of surface geology upon earthquake-induced mo- tions, the stability of foundation materials during earth- quakes, and the variety in response of design structures to earthquake-induced motions. Such information is utilized by the C&GS to compile seismic risk maps which enable Federal, State, and local authorities to formulate policies for building codes and to institute studies for regional, urban, industrial, and land use planning. Additionally, staff members of ESL's EML have served as consultants with or speakers to such local California groups as: The Office of Emergency Planning Regional Prepared- ness Committee, developing emergency plans to be put into effect in the event of a major earthquake in that State; the Society of Real Estate Appraisers; the Coordinating Committee for East Bay Fault Slippage in Hayward; a meeting of representatives from engineering-geology firms in the San Francisco Bay area; and the Governmental Services Committee of the City of San Francisco, concern- ing a proposed parapet hazard abatement law. Seismic risk map of the conterminous United States showing four zones of no damage, minor damage, moderate damage, and major damage. 79 Tsunami Generation Research on the processes by which an underwater earth- quake generates a tsunami is underway. Techniques are be- ing developed and instruments improved for measuring and detecting tsunamis in the open ocean; improved forecasts of tsunami travel times and wave heights onshore will pro- vide advanced, reliable warnings on the severity of the hazard. Research by the C&GS's Geophysics Research Group into the mechanism of tsunami generation involves correlations of earthquake mechanism, water depth, and ocean bottom topography. The objective of the tsunami-supporting re- search studies is the development of a technique to identify and interpret, immediately following an earthquake, those source parameters of the earthquake that can be related to the generation of tsunamis. Use of seismic phenomena to identify tsunami-generating earthquakes would permit much earlier warnings and would greatly reduce the potential for loss of life and property. Studies were made by the Geophysics Research Group which suggest that tsunami- generating earthquakes may be multiple-shock events, indi- cating successive ruptures over a long zone. Research is underway to determine whether this study result is a valid criterion for use in efforts to discriminate earthquakes which produce tsunamis. In another approach to the problem of finding a method for identifying tsunami-generating earthquakes, the Group developed a computer program combining P- and S-wave focal mechanism solutions. This computer program will be used to study the relationship in orientation of focal mecha- nism to the generation of tsunamis. One of the basic research programs on tsunamis is con- ducted by the Pacific Oceanographic Laboratories (POL) of RL and is designed to increase understanding of the gen- eration, propagation, and onshore runup mechanisms of tsunamis to improve the operation of the Pacific Tsunami Warning System. During the reporting period, a cooperative research pro- gram of the POL and the University of Hawaii was under- way; progress has been made on developing several types of deep sea tsunami gages, both free-fall and cable-con- nected. Six deep sea free-fall wave measurement systems have been completed and shipped to Amchitka Island for use in an experiment in the Aleutian Islands of Alaska. The design is complete and components are being life-tested for a permanent tsunami-measuring system which will be placed on the sea bottom under a North Pacific weather ship. Com- puter programming was also done in connection with vari- ous studies, including hydrodynamic modeling of estuaries, numerical calculation of directional spectra of wave refrac- tion, computation of propagation of free and edge waves, identification of earth regions based on seismic spectra, and spectral analysis of time series containing gaps. Travel time charts, obtained by computer, have been produced for the Pacific Tsunami Warning System. Significant advances are being made at the University of Hawaii in instrumentation for measuring and detecting tsunamis in the open ocean. Development of accurate tsunami travel time tables for the open ocean and shallow water situations, involving different ocean bottom topog- raphy, is underway. This information will result in more accurate and rapid forecasting of tsunami generation, im- proved advanced warning of its potential destructive power, and better planning by local authorities for the construction of dikes, jetties, and other nearshore facilities as a means to reduce loss of life and property in coastal regions sub- ject to destructive tsunami occurrences. CARTOGRAPHY Service Programs ESSA has the responsibility for the production and main- tenance of up-to-date aeronautical charts and related infor- mation required for all types of aviation within the United States and for U.S. civil aviation in foreign air space where navigational information needs are not otherwise provided. The requirements for products to meet civil aviation needs and those essential to the management of the National Air- space System are prescribed by the Federal Aviation Ad- ministration (FAA). Specifications for aeronautical charts, designed to provide timely and accurate information to both civil and military users with minimum duplication of production, are developed jointly through an interagency agreement between the Departments of Defense (DOD), Transportation (DOT), and Commerce (DOC). Aeronauti- cal charts are the primary media through which rules and regulations pertaining to the National Airspace System are made available to the aviation community. Visual Charting Visual Charts are used by pilots engaged in contact flight under Visual Flight Rules (VFR). These Charts graphically portray topographic and cultural detail — such as drainage, roads, railroads, and other distinguishing landmarks — for terrain reference. ESSA's C&GS prepares four different types of Visual Charts, issuing revisions at intervals rang- ing from 16 weeks to 1 year. Included in the four series of VFL-related products are: Locals at 1:250,000 scale of high-density terminal areas; Sectionals at 1:500,000 scale for slower speed aircraft; World Aeronautical Charts at 1:1,000,000 scale for higher speed aircraft; and a smaller scale Wail Planning Charts. Instrument Charting Instrument Charts contain airways, radio facilities, and other complex information pertaining to the National Air- space System for those flying under the Instrument Flight Rules (IFR). Included among the Charts of this series are: Enroute High and Low Altitude Charts to assist pilots in enroute navigation; Instrument Approach Procedure Charts to provide information on instrument approaches to airports, with approved procedures; and Standard In- 80 strument Departure (SID) Charts — ^the newest series — ^to show preferred routing from takeoff to enroute fixes and to reduce air traffic control clearance communications. To meet the prescribed format and time schedule for the SID series, cartographic activities for the series within the C&GS were expanded during FY 69. This new series was funded during FY 69 by FAA, with the publication schedule providing one SID Chart every 8 weeks. These SIDs will be produced in bound volumes, one for the East- ern and one for the Western United States, replacing 31 charts that formerly covered the conterminous States; a third volume will be produced for Alaska. Other IFR-related products include: Controller Charts to provide FAA personnel at Air Traffic Control Centers with a graphic display of all current and pertinent data neces- sary to manage their responsible portion of the National Airspace System; Central Airspace Reservation Facility (CARF) Charts to permit FAA personnel to coordinate mili- tary and important civil air traffic with Air Traffic Control Centers; and Airport Obstruction Charts to show pilots ob- struction locations, heights off runway ends, precise air- port elevations, runway lengths, and other data required for safe maximum aircraft loading. Aircraft Position Charts are designed to meet unique information requirements of long-range international flights. Research and Development Programs The tremendous growth in the Nation's aviation during the past 30 years has caused an increasingly crowded air- space problem which at present requires a total reevaluation of the National Airspace System and the means for graphi- cally describing it. Although aeronautical charting has ful- filled the aviator's informational needs during these past 30 years, time is no longer available within present re- sources to make in-depth studies on terrain depiction tech- niques, to evaluate graphic arts processes, or to provide color composition possibilities for meeting the urgent prob- lem of describing the National Airspace System graphically. Valuable knowledge gained from previous research studies was partly applied to existing charts and will be employed in information portrayal solutions to meet new charting requirements. Past research on color-process printing made possible the elimination of one five-color press run for each Visual Chart produced. Although simulated-process printing has been successful in reproducing tints, the selection of "primary colors" to satisfy the solid line work represents an important break- through in meeting the specifications for navigational charts. This simulated-process printing method requires the manu- facture of precise interposing film screens and the develop- ment of a special color chart. Computer-Assisted Cartography During the past 2 years, significant progress was made toward the goal of increased use of automation in chart production. The technical feasibility of the computer-assisted cartographic data-handling system and the ability to ac- complish on-line updating of certain important aeronautical charting programs were demonstrated. A major obstable to automation of the cartographic proc- ess was overcome by the unique characteristic of the sys- tems concept that now permits the cartographer to "get at" the computer-stored data base, to manipulate and work on these data, and to arrange them to satisfy the requirements of the cartographic product. This characteristic is absolutely essential if full automation is to be a practical cartographic tool. To determine whether automation could be accomplished and whether full-scale implementation was justified, a de- tailed systems design was developed and its soundness proven in an o{>erational environment. The C&GS let a contract in June 1968 to implement a pilot system for a selected series of cartographic products covering a limited geographic area. The Alaska Enroute Low Altitude Charts and the Alaska Instrument Approach Procedure Charts were selected for the initial test. The pilot system procedure in- volved the establishment of a parallel production operation in conjunction with the present manual operation; this pro- cedure provided training for C&GS cartographic personnel and permitted evaluation and systems design evolution of the system. Frequent revision schedules and the increasing tendency to relate publication cycles to the National Airspace Amend- ment Day, which occurs every 28 days, make automation of aeronautical charts a challenging cartographic problem. Revisions to the Instrument Approach Procedure Charts are published weekly, the entire Enroute High and Low Altitude Chart series is produced every 4 weeks, and the Visual Charts are available on a 6-months' schedule coin- cident with the effective date of an airspace amendment. The principal constraints on meeting the increasing de- mands for timely information of air-cartographic materials rest upon the annual methods of cartographic revision and production and upon the shortage of skilled cartographers. Developing new systems to permit shorter response time and to reduce the cost of production are urgently needed. MARINE GEOPHYSICS Research and Development Programs Marine geophysics is of continuing and increasing impor- tance as the need grows for more accurate descriptions of the land-sea boundary for geodetic, geomagnetic, and seis- mological investigations. This subject is discussed within this chapter rather than in Marine Description, Mapping, and Charting because the techniques and methods relate to the solid earth phenomena, although the measurements are largely made from water-based platforms. The growing economic importance of marine geophysics has generated new requirements for marine geodetic and geomagnetic data because of the potential commercial de- velopment of the Continental Shelf. 81 Research programs in marine geophysics embrace the disciplines of geodesy, geomagnetism, and seismology and largely involve the land-sea interface. The focus of ESSA's marine geophysics program during the reporting period was directed toward suboceanic struc- ture investigations, geotectonics, sedimentology, and ocean basin characteristics. Research was conducted by both the Atlantic Oceanographic Laboratories (AOL) and the Pa- cific Oceanographic Laboratories (POL) of RL to gain a clearer understanding of the structure, nature, and evo- lution of the ocean basins and the continent-ocean basin boundary. Major research efforts centered on the study of island arcs and associated deep sea trenches because tectonic forces in the early phase of their evolutionary cycle are still active in those geomarine areas. Research of both Oceanographic Laboratories was accomplished through analysis, interpretation, and presentation of gravity, magnetic, and seismic data from a systematic acquisition program. Suboceanic Structure Investigations A number of studies and investigations were conducted by the Oceanographic Laboratories during the past 2 years as part of the international program to investigate the earth's upper mantle. Investigators from POL completed and published a marine geophysical study of an area of 120,000 square miles off the coast of California and con- cluded an investigation of an island arc structure in Indo- nesia in FY 68. A study of the earth's crust underlying the North Pacific using magnetic characteristics of the crust was conducted; structural interpretations for the Pacific Basin north of Alaska based on gravity observations were also made. A continuous geophysical profile (bathymetry and magnetics) across the South Pacific at latitude 35° S. was undertaken and completed, and the results were pub- lished. This profile revealed numerous submarine volcanoes, reported the existence of a new submerged mountain range, and located another previously known mountain system with more accuracy. Scientists of POL discovered two Fracture Zones — ^Amlia and Adak — normal to the Aleutian Trench with offsets of 50 kilometers and a major deep sea Channel — Seamap — in the Aleutian Abyssal Plain during FY 68. This deep sea Channel is a geologic feature of the Northeast Pacific predating the subsidence of the Aleutian Trench. The sig- nificance of this Channel to studies of Pacific Ocean tec- tonics is considerable, for its existence has provoked new thought on the pattern of sediment deposition in the North- east Pacific. Also, POL scientists discovered a westward extension of the Murray Fracture Zone; the former hy- pothesis that the Zone trended into the Marcus-Necker Ridge is now questionable. Results of the magnetic char- acteristics associated with the Amlia and Adak Fracture Zones, and studies of the characteristics of the westward extension of the Murray Fracture Zone and of the Seamap Channel were published in FY 69. Final reports on the morphology of an area north of the Hawaiian Ridge and the general bathymetric setting and gravity anomaly of Cobb Seamount, and initial reports on the gravity of the Aleutian Trench were presented in FY 69 by POL. Field work was conducted in support of the con- tinuing study of magnetic anomalies and topographic data in the central North Pacific. Geotectonics Investigations into geotectonics by AOL involved re- search directed toward the development of a fundamental understanding of the genesis, tectonics, and geomorphic evolution of the continental margins (shelf and slope) and deep sea floor. These studies emphasized such large-scale problems as continental drift, geological relationship be- tween continents and ocean basins, and origin of ocean basins. During the past 2 years, various geotectonic field investi- gations were conducted. Among the completed investiga- tions were studies along the continental margins of Australia and northwestern Africa; an analysis and interpretation of data on sea-floor spreading and continental drift were also concluded. The geomorphology and geological structure of the North African continental margin were delineated to provide additional evidence of sea-floor spreading. AOL scientists conducted research in other geographic regions on the structural fabric of a number of continental shelf and slope areas; full explanations of these phenomena in terms of continental rift and drift hypotheses were an- ticipated. An analysis and interpretation of data collected along the east coast margin of South America were also accomplished. One of the principal efforts during FY 69 has centered on the "jigsaw fit" of the edges of the Australian and Antarctic continents. A computer-evaluated reconstruction of the postulated Australia-Antarctic protocontinent shows a high degree of probability that these two continents were once joined. Sedimentology Sedimentological research includes an analysis and inter- pretation of the source, diagenesis, composition, and trans- portation of ocean basin sediments. Standard sedimentologi- cal and geochemical techniques are applied to samples col- lected in systematic surveys; these surveys are designed to increase basic knowledge of the processes and geochemistry of the sea floor. Research into the mass physical properties of submarine sediments provides a clearer understanding of the stability of the sea floor, effects of loading and shock, engineering properties — shear strength, density, and poros- ity — of the sea floor, and the process of lithification. In FY 68, scientists in both Oceanographic Laboratories completed studies on the distribution of mass physical prop- erties of submarine sediments in the North Atlantic and North Pacific. Measurements of shear strength, bulk density, and pore pressure were completed by AOL investigators 82 .^'^ >«- '.^'^' »i^ ' '■-■\ ^^r^ Ocean floor at depth of 537 fathoms (3,222 feet) south of Australia. off the coast of Massachusetts. Clay mineralogy samples, collected from the Java, Mindanao, and Mariana Trenches, were laboratory-analyzed. A geochemical study of the car- bonate (high and low magnesium carbonate and aragonite) and nonoarbonate content of samples from the Straits of Florida was also completed. Studies on the degree of variation in selected mass prop- erties, both geographically and for different types of sub- marine sediments, were completed in FY 69. With the aid of a submersible, a detailed study of the local (400 square centimeter area) variability of certain mass properties was completed for a deep sea carbonate deposit. Field work was completed on the in-place measurements of shear strength and bulk density. Presently, an investigation is in progress on sedimentary characteristics of the Tobago Trough in the southeastern Caribbean Sea that will define the dynamics and processes involved in the deposition of material in this Trough. Ocean Basin Characteristics Studies on ocean basin characteristics focus on improved understanding of the processes determining the structure of sea floors, continental shelves, ocean basins, island arcs, and deep sea trenches, and of those processes involving sedimentary deposition and geomorphology. During the reporting period, AOL scientists were in- volved with various investigations describing the sea floor morphology, interpreting the effects of sedimentary and tectonic processes, studying the origins and prominence of morphological features, and predicting morphological changes. Work continued on the study of the bottom morphology of Chesapeake Bay (15 sheets at a scale of 1:50,000) and on the depositional and erosional history of the lower Potomac River. Another accomplishment by AOL researchers was the col- lection and interpretation of data on the continental margin of Brazil; a bathymetric map was completed. In FY 69, researchers prepared a detailed bathymetric study and seismic reflection profiling along the eastern margin of canyons extending from the platform into the Atlantic Basin. An investigation of the Amazon Canyon off the Amazon River sought to delimit and determine the possible origin of the Canyon. Other studies conducted by AOL have determined the shallow structure of the entire continental margin of Brazil and Uruguay that developed following the postulated sepa- ration of South America and Africa by the creation of the South Atlantic Basin. Intensive efforts in the southeastern Caribbean Sea, at the junction between the Lesser Antilles island arc and the South American continent, have placed severe constraints on any postulated lateral movement be- tween the island arc and the continent as predicted by the recent plate tectonics concept. Additional accomplishments by AOL within marine mor- phology during FY 69 include a bathmetric map from the Upper Mantle Project area off the coast of California; de- scriptions and interpretations of two submarine canyons — Cayar and Trou sans Fond — along the Atlantic margin of Africa; a detailed bathymetric map of the Straits of Florida and an accompanying test; and an interpretative report on a related series of submarine canyons off Ceylon. Global data collected during the world cruise of the USC&GS ship Oceanographer in 1967 were processed and analyzed, and a summary report prepared during the re- porting period. Scientists at POL completed analyses on several aspects of the geophysical data collected. An in- vestigation of the East Australian Current by the Ocean- ographer in September 1967 resulted in the discovery of a jet in the Current; the existence of a countercurrent be- neath the Current was also verified. Reduction and analysis of data obtained in the study of Bimini Inlet in the Bahamas during 1967 continued; ana- lytical expressions were developed relating bottom geom- etry, fluid flow, and sediment transport in this Inlet en- vironment. MARINE DESCRIPTION, MAPPING, AND CHARTING ESSA's programs relating to Marine Description, Map- ping, and Charting fall within the fields of marine navi- gational charting and oceanography. Included in these programs are studies of coastal tides and currents and the interaction of the sea and land along coastlines and estuaries. The principal service activities of ESSA in descriptive oceanography involve tides, tidal currents, and the hy- drography of coastal waters and estuaries. The increased effort in bathymetry (bottom topography) of the Con- tinental Shelf and deep ocean areas is attaining importance as a specific service activity. The tide program of ESSA consists of the operation by the Coast and Geodetic Survey (C&GS) of approximately 200 permanent or temporary tide gages to monitor tides along the coasts of the United States and its possessions. Data from these gages form a basis for determining the tidal characteristics from which tide predictions are made. The datum planes used as a reference for depths on nautical charts are determined from tidal data. Tidal current service programs include the systematic collection of current observations and the reduction, analy- sis, and interpretation of the resulting data. These data are subsequently used in experimental and theoretical studies of estuarine dynamics, in the maintenance of coastal fisheries, and in sedimentation mechanics. Characteristics of tidal currents are described, predicted, and published annually by the C&GS. The service programs in hydrography are concerned with various operations necessary for the production of nautical charts and related publications required to improve the safety of marine navigation. These programs encompass such activities as hydrographic surveys and mapping, in- volve investigations of hazards to navigation and locations of aids for the marine navigator, and include U.S. Coast Pilot information. A variety of nautical charts is produced by the C&GS as a result of these surveys. The research and development (R&D) efforts in Marine Description, Mapping, and Charting are the joint responsi- bility of the C&GS and the Research Laboratories (RL). ESSA's research programs relating to oceanography are concerned with improving knowledge of tidal propagation in both estuaries and the deep ocean, estuarine dynamics, nearshore ocean circulations, bathymetry, deep ocean cir- culations, wave phenomena, and sea-air interactions. Be- cause marine geodesy, geomagnetism, and seismology are concerned with the solid earth phenomena at the bottom of the sea, these subjects are discussed under Earth De- scription, Mapping, and Charting. The C&GS operates a fleet of 15 oceangoing vessels to assist ESSA's service and research efforts for the collection of information along the Continental Shelf and deep ocean basins. These vessels measure the bathymetry of the oceans, the ocean and estuarine currents for navigational purposes, and such geophysical parameters as marine gravity and geomagnetism. MARINE NAVIGATION, MAPPING, AND CHARTING Service Programs The marine navigation, mapping, and charting program involves the production of nautical charts and publications for marine navigation. This program includes hydrographic surveys for large-scale shipping operations, photogram- metric shoreline surveys for coastal operations, and the compilation, reproduction, and distribution of nautical charts, U.S. Coast Pilots, and related navigational infor- mation. This program element also involves investigations of navigational hazards and locations of aids to the navi- gator. Objectives of the program are to complete and maintain on a current basis the charting of the coastal waters, including harbors and estuaries of the United States and its possessions. Nautical Charts Nautical charts are the principal products of the marine navigation, mapping, and charting program. These charts are basic tools for the safe and efficient conduct of water- 83 84 borne commerce and are vital to the rapid expansion of marine industries and recreational boating. Six types of charts were published by the C&GS during the reporting period. Four types — Sailing, General, Coast, and Harbor Charts — are prepared for general users at vary- ing scales of detail ; and two types — Small-Craft and Special- Purpose Charts — are designed for particular user groups. Mariners plying the oceanic waters find Sailing Charts useful to plot their course between distant coastal ports and on approaches to the coast. They turn to General Charts to fix a position from visual sightings and radar images. Mariners trace their passage on Coast Charts if they intend to navigate nearshore coastal waters, enter large basin har- bors, and traverse certain large inland passages. For safe navigation within active harbors and restricted channels and passages, they choose Harbor Charts. Recreational boaters seeking information on marina loca- tions and facilities, tides and currents, anchorages, the Weather Bureau's (WB) Marine Weather Services, and basic nautical rules look for such material upon Small- Craft Charts. For plying coastal waterways, boaters acquire Special-Purpose Charts such as the Intracoastal Waterway Charts, covering the Atlantic and Gulf Intracoastal Water- way, to locate themselves. This latter series of charts is being converted to the Small-Craft Chart format at the present time. Ship Operations Hydrographic surveys are performed to determine water depths and bottom configuration and characteristics, to lo- cate physical obstruction to navigation, and to portray navigation aids for use in producing a graphic description — nautical charts, bathymetric maps, and Coast Pilot infor- mation — of navigable waters to insure safe passage for the mariner. Near the coast and in protected waters, sur- vey work is done by launches operating from larger vessels or from shore bases. In unprotected waters and in the open ocean, work is performed by survey ships. Coastal Mapping Coastal mapping consists of photogrammetric shoreline surveys. These surveys employ photography and office com- pilation to delineate shorelines, to locate onshore and off- shore features, and to establish and extend geodetic control required for hydrographic surveys and for nautical chart compilation and maintenance. U.S. Coast Pilot Production The preparation of Coast Pilots involves extensive field investigations and office compilation of data collected on the coastal waters of the Nation. The eight-volume Coast Pilots series contains a wide variety of navigational infor- mation which cannot be adequately presented on nautical charts. This information includes regulations for general and local navigation; descriptions of prominent natural and cultural shoreline features; accounts of channels, anchor- ages, hazards, and tide and current characteristics; de- tails on pertinent weather conditions for the area; and listings of available port facilities. Two Coast Pilot volumes are revised and issued each year; yearly supplements to the remaining six volumes are also prepared. Research and Development Programs The R&D program for marine navigation, mapping, and charting increases the accuracy, timeliness, and efficiency of marine chart production. Current efforts are directed toward automation and integration of survey data acqui- sition and processing systems, automation of chart produc- tion and maintenance systems, and improvement of tech- nical and managerial procedures. Automated Chart Production Development of automated cartographic compilation sys- tems is underway to improve charting production processes and to decrease the time delay between acquisition of sur- vey data and distribution of the final product. To expedite and improve the processing of data by avail- able technology, C&GS has instituted research on the auto- mation of portions of its data processing operation. Cost- effectiveness studies were used to reveal which areas of operation offered maximum opportunities for increased effi- ciency should automation be introduced. Studies indicated that an automated data system would achieve a balance between data acquisition and processing, permitting a re- duction in the backlog of unprocessed data and providing a foundation for expansion to match increases in data flow. Another research project initiated by the C&GS during the reporting period concerned the development of an in- formational system which would store, retrieve, and trans- mit information acquired with C&GS facilities but not used in its own products, and information subject to requests from users outside the C&GS. A study was performed to identify the types of data stored in C&GS working and archival files necessary for the production of its regular products. An inventory of data acquired by the C&GS as a service to other groups was also determined. Traditional requests to C&GS for various tyj>es of data were also sum- marized. From all of these studies, an information-handling system plan for the C&GS was developed, including a policy for handling special information required by the Environ- mental Data Service (EDS) and the National Oceanographic Data Center (NODC). Hydrographic System The need to automate survey data acquisition and proc- essing activities is quite apparent. The slow hand-processing techniques in use have resulted in a backlog of unreviewed data and a consequent delay in producing safe, efficient nautical charts in a timely manner. Automation speeds the processing of survey data, allowing their distribution to the user while still reasonably current. Automation will be introduced aboard ships to permit real-time or near real- time digital logging and plotting, on-line and off-line data re- duction, evaluation of data for computer program logic, and near real-time preliminary verification of survey integrity. 85 To take advantage of the benefits of data automation, the C&GS has sought to develop a shipboard digital hy- drographic data acquisition system. Such a system, using a computer configuration, automated plotter, electronic navi- gation system, and digital echo sounder, has been tested aboard the USC&GS ship Whiting. The ship was guided along predetermined straight-line courses by computer- generated instructions to the helmsman. During the oper- ation, time, depth, position, depth correction, and position correction data were logged in digital form in real-time to achieve a real-time plot of the depth at the vessel's location. Following each day's work, the analog depth record was checked and required changes applied to the digital record. Subsequently, the digital records — tapes and printouts — were forwarded to processing centers ashore for final auto- mated smooth plot. Additional research is underway on: (1) documentation of the experimental computer programs; (2) development and testing of improved computer programs and subroutines for the Whiting experiment; (3) design of an improved automated data system for C&GS hydrographic ships other than the Whiting; (4) development of an improved capa- bility to input tidal data and other correction factors; and (5) development of effective means to filter various in- accuracies and noise from the digital echo-sounder data. The C&GS initiated the development of a high-speed hy- drographic launch system to expedite hydrographic sur- veys. Construction of a high-speed launch was completed in June 1968, and tests of overall system performance fol- lowed. These tests sought to determine suitable transducer arrangements and to evaluate basic sensor response during high-speed hydrographic survey operations. Recently pro- cured data control units were used as an aid in develop- ing an effective system to process the data — including ac- curate position information — acquired during a high-speed test survey. Survey data resulting from this test have been processed through final review and adjudged adequate for charting purposes. As a result of this success, a Whiting- type computer/plotter array has been ordered for the high- speed launch; testing of this latter system is anticipated to begin in September 1969. OCEANOGRAPHY Service Programs The ESSA oceanographic fleet — vessels operated by the C&GS — conducts research studies and geophysical surveys which describe the ocean environment. These geophysical surveys involve systematic observations of physical and chemical oceanographic parameters; the survey results are then made available in publications or on maps for users interested in resource exploration, national defense, and scientific understanding of the ocean and its processes. Tide and Tidal Current Observation and Prediction The primary objective of the tide and tidal current ob- servation and prediction program is to provide astronomical tidal prediction services for commercial, naval, and rec- reational interests. The program also furnishes data on physical processes relating to beach erosion and pollution control. The program establishes datum planes for refer- encing bottom soundings on charts and delineating legal shoreline boundaries. A network of about 120 permanent gage stations is main- tained for these purposes. Data from an additional 80 temporary gage stations, placed in selected operational areas each year to support hydrographic surveys, increase the effectiveness of the permanent network. All C&GS hy- drographic survey vessels are equipped with portable gages, enabling them to establish tide stations in operating areas for the determination of tide corrections as soundings are made. Data collected by the tidal gage networks provide pre- dictions for the United States and its possessions; predic- tions for other parts of the world are obtained from various nations on a cooperative basis. Tables of the worldwide daily tide predictions are published annually in four vol- umes by ESSA — 1 year in advance. A systematic collection of tidal current observations is made in coastal waters, embayments, and harbors of the United States. Approximately 75 stations are occupied an- nually for periods ranging from 100 hours to a month. Based on the observational data collected, predictions are made of slack water times and maximum tidal current times, speeds, and directions. These tidal current predic- tions are published annually in two volumes. In addition, tidal current chart atlases are published for some major U.S. harbors and waterways. One vessel, the USC&GS ship Ferrel, operates exclusively for tidal current work, although current meters are carried on all C&GS vessels. Bathymetric and Geophysical Mapping Bathymetric mapping involves the systematic charting of sea bottom topography to provide information for the ex- ploration and development of mineral and fish resources. Basic bathymetric maps at 1:250,000 scale are planned for the entire U.S. Continental Shelf. Larger scale bathymetric mapping of selected oceanic areas is planned to provide ad- ditional coverage for exploitation of marine resources. The bathymetric series will be constructed from both existing sounding data obtained from nautical charting activities and from newly generated data gathered specifically for that purpose. While bathymetric maps are essential to the delineation of bottom topography, geophysical maps are also needed to provide a more complete description of the sea floor for scientific purposes and for better evaluation of resource potential. Intensities of the magnetic and gravitational fields of the earth and the subbottom configuration obtained by seismic profiling are measured simultaneously with depth measurements during oceanographic surveys. Maps of mag- netic and gravity anomalies (the difference between actual measured values and theoretical regional field values) and subbottom structures are made at the same scale as the bathymetry, either separately or as overlays to the bathy- metric map base. 86 Lowering of stereo pair deep sea camera into the ocean. Research and Development Programs Although the C&GS provides ESSA's service programs in oceanography, it shares research activities in the field with another ESSA component. This component, RL, has the primary responsibility for basic research in physical oceanography. Research work is performed by the Atlantic Oceanographic Laboratories (AOL), Pacific Oceanographic Laboratories (POL), and Geophysical Fluid Dynamics Lab- oratory (GFDL). The objectives of both AOL and POL are to seek new knowledge of the Atlantic and Pacific Oceans, Gulf of Mexico, and Caribbean Sea. Scientists of both Laboratories study the influences and interactions of the oceans with their physical environment, extend the marine services and operations of ESSA, and apply knowledge gained to national needs for improvement of oceanographic investigative tech- niques and instrumentation. Oceanographic research in GFDL is directed toward fundamental understanding of 87 large-scale circulation systems of the atmosphere and oceans. This research on circulation will develop a comprehensive theory of geophysical fluid systems and processes. Such a theory could lead to improved short- and long-range weather predictions and could provide techniques to dis- cover and test the means for large-scale weather modifi- cation. Research activities of the RL in oceanography include structure and motions of the ocean, ocean circulation, land- sea interaction, and sea-air interaction. Bering Sea Oceanographic Study Among C&GS activities in oceanography underway dur- ing the past 2 years was a cooperative study with the Geo- logical Survey of the bathymetry, gravity, magnetics, sedi- ments, and currents of the northern Bering Sea of Alaska. This study involved collection of hydrographic and ocean- ographic survey data during the 1968 and 1969 summer seasons and subsequent issuance of bathymetric, gravity, and magnetic maps by the C&GS. The survey included hy- drography, gravity, and magnetics at a line spacing of 1 to 2 miles. Over 200 sediment samples were taken and sent to the Geological Survey for analysis and processing. Marine Observation Systems During the reporting period, C&GS continued research on an oceanographic buoy system for measuring time de- pendent variables of the ocean. This system aims at solving problems of oceanic sensor design and construction; data storing, recording, and telemetering; power supply; place- ment; maintenance; and retrieval. The Ocean Data Environmental Science Services Acqui- sition (ODESSA) buoy system, which consists of sensors for measuring current velocity and direction, temperature, salinity, and pressure, has been under development and is approaching operational status. The ODESSA system in- cludes a radiotelemetry link with scheduled interrogations so that data can be accumulated on board or recorded re- motely. One aspect of C&GS's research on this system was the adaptation of the system to deep ocean operations. The approach used involved adapting the signal links, con- tainer seals, and other features to deep ocean application and completing the final debugging of the original develop- ment. The system was given a series of laboratory and field evaluations, after which successive improvements were incorporated. Field tests were performed in the Potomac River and off Bimini Island in the Bahamas. The success of the C&GS's three-point mooring of a stable deep underwater platform in 4,500 feet of water about 100 miles off the west coast during an endurance test in FY 67 and FY 68 prompted an analytical study in FY 69 of platform movement under different conditions of depth and currents, including the measurement and analysis of actual platform motions. The performance of the full-scale plat- forms was monitored for verification during the past Fiscal Year. The Coast Survey Marine Observation System (COSMOS) ocean tide system includes the development of methods for measuring deep sea tides and other ocean characteristics. A pressure tide gage was placed and tested during the winter of 1968-69 on the COSMOS platform in the Atlantic Ocean, with another on the sea bottom underneath the platform; both gages recorded on the same recorder sit- uated on the platform. Comparisons of recorded data indi- cated the value of using this platform as a base from which to measure tides. Accelerometers and tiltmeters were also placed on the platform to study platform motion. A complete procedure for installation, positioning, and retrieval of COSMOS platforms was developed and tested in operations off Barbados in the West Indies during the summer of 1968. After debugging, the procedure was em- ployed in the fall of 1968 and again in 1969 with additional platform installation. Another phase of the C&GS's research into marine ob- servation systems involves the COSMOS satellite telemetry studies seeking the development of position-locating equip- ment. This research is concerned with development of a practical buoy antenna and supporting buoy combination to transmit oceanographic and meteorological data to a land station by means of a synchronous Applications Tech- nology Satellite (ATS). The Omega Position-Location Equipment (OPLE) was supplied by the National Aero- nautics and Space Administration (NASA) and installed in a buoy furnished by C&GS. Following laboratory tests, the buoy was moored in the Atlantic Ocean off Miami, Fla., to explore the buoy-satellite communication link. Later, the buoy was made free-floating to explore the OPLE's buoy- tracking ability. Uninstrumented tests were also conducted. As a result of these tests completed in the summer of 1968, a new buoy hull was built. The buoy equipped with OPLE will eventually make data available from previously in- accessible sites. Extensive research into the existing state of buoy and buoy antenna design, buoy mooring, and buoy retrieval is currently underway. Structure and Motions of the Ocean Studies directed toward the structure and motions of the ocean were conducted by the POL on the state, proc- esses, and dynamics of the Pacific Ocean, with emphasis on such large-scale features as seasonal or regional patterns; support was also given to microscale, short-term variability, and isolated phenomena studies. Programs during the re- porting period stressed the study of circulation dynamics of ocean water masses, ocean current systems, heat budgets, salt budgets, and volume and mass transport. POL scientists conducted joint research with the Depart- ment of Oceanography of the University of Washington in testing, through ocean experiments, hypotheses concerned with the propagation of semidiurnal internal waves to the open ocean. Oceanographic investigators at the University developed a theoretical model to describe the generation of internal waves by the surface tide wave as it impinges on the Continental Shelf. The model describes internal waves in terms of normal modes. By using the model, and knowl- edge of local bottom configuration and density structure, it is possible to predict details of internal wave propagation seaward from the Shelf. Oceanographic reseachers at the University, under Office of Naval Research sponsorship, performed computer simu- lations of the normal mode model to aid in the deployment of sensors. Instrumentation for the observation program was provided by the Navy. ESSA assigned the USC&GS ship Oceanographer to the project. The Joint Oceanographic Research Group (JORG) of POL is coordinating the obser- vation program, specifying the experiments, and planning for data processing and analysis. Scripps Institution of Oceanography also participated during field operations of the observation program. POL's investigation in FY 69 showed that at the ex- perimental site — latitude 42° N. — standing waves of semi- diurnal frequency are generated over the Shelf and free waves of the same frequency are propagated seaward. These internal waves satisfy the requirements of this experiment because they emanate from a well-defined source and propa- gate as a line of high energy at a known frequency in the spectrum. Details of their seaward propagation can be pre- dicted. The normal mode model was tested by 11 days of measurement at the experimental site. Analysis of data is underway. Field measurements supporting the Polar Front — North Pacific Intermediate Water Study, a study of physical and chemical structure being conducted by POL as a cooperative effort with Oregon State University, were extended west- ward to longitude 155° E. Data for fall and winter condi- tions were obtained for comparison with spring conditions measured in FY 68. Analysis of the unexpectedly complex structure of the Intermediate Water, directed toward deter- mining its origin, development, and trajectory, continues. Studies were made and reports prepared by POL on cur- rents in the Tasman Sea — one on a previously unknown countercurrent of the East Australian Current, and the other on the speed and direction of bottom currents in the Tasman Sea measured for the first time. Measurements were made utilizing an automated current meter, an acoustic signalling device, and bottom photography. Another study on the properties of the central North Pacific deep water at 3, 4, and 5 kilometers revealed a gradual warming, dilution of salinity, and reduction of dissolved oxygen in a general south to north direction. The report, based largely on ESSA's Scientific Exploration and Mapping (SEAMAP) Program data, included a pro- posed trajectory for the water which indicates a circuitous path for the extreme northern region. Analysis of geostrophic data, supplemented with para- chute drogue measurements, revealed a 37 percent reduc- tion in the mass transport of the Alaska Stream from winter to late summer, whereas year-to-year variation during the same period is small. This variability is attributed to sea- sonal variations in atmospheric pressure patterns. A study by POL scientists of temperatures and other properties of water confined to deep basins, trenches, and deeps off the west coast of Central and North America re- vealed an anomalous situation in the Panama Basin, sug- gesting either discernible heating of bottom water from geothermal sources or presence of an uncharted topographic barrier. As the latter seems improbable, the thermal gradi- ent was used to develop a coarse flow pattern. A more precise, new method for computing the mean vertical speed of sound through the ocean, applicable for echo sounding, and equations for utilizing the method in the central Pacific Ocean were published; the method is programmed for routine use at the C&GS's Pacific Marine Center in Seattle, Wash. During the past Fiscal Year, the AOL completed a time series study of tracklines following the core of the Gulf Stream. An evaluation of the potential of orbiting space- craft for mapping large-scale oceanic phenomena was also initiated with the objective of applying the observations to the core of the Gulf Stream. A cooperative study — involving AOL, Sippican Corpora-, tion, and Humble Oil Corporation — ^was conducted in FY 69 on the use of bathythermograph observations for oil tanker transits between gulf coast and northeastern Atlantic coast ports to identify displacements of the core of the Gulf Stream. A long-range goal is to develop a technique that may be applied in other areas, particularly on routes to the Persian Gulf. Ocean Circulation Research in ocean circulation by AOL scientists involved the description of the dynamics and physical properties of the oceans, including advective and convective aspects of circulation and interactions of circulation with the at- mosphere and the sea floor. Particular emphasis in FY 68 was directed toward circulation of waters that affect the environment of the U.S. east and gulf coasts. Preliminary analysis of Gulf Stream data obtained during monitoring of the 15° Celsius isotherm path showed a progressive wave pattern in the meanders. Data measurements acquired at ocean stations along a section off Charleston, S.C., at predetermined time intervals were reduced and data inter- pretations are underway. A study of horizontal divergence, using drogue data, was partially completed by AOL; a more comprehensive set of data was obtained in June 1968. An- other AOL study completed was an investigation into the variation of water temperatures related to the passage of hurricanes. In preparation for the Barbados Oceanographic and Me- teorological Experiment (BOMEX), the AOL used COSMOS and tautwire buoy arrays (with ODESSA sensors), and salinity-temperature-depth (STD) time series from station- ary ships for studies on the variability of different physical parameters, their coherence on various scales in three-dimen- sional space, and their relationship to atmospheric data ob- tained simultaneously. Gulf Stream and Florida Current variability research continued. The GFDL contributed to investigations on the dynamics of ocean circulation through the development of numerical models. Calculations for these investigations utilized simple ocean basin topography. More detailed numerical models 89 were constructed and tested during the reporting period using actual shorelines and bottom topography of the world's major oceans. Both temperature and salinity were included to permit an accurate computation of density. Wind stress, temperature, and salinity were specified at the surface, based on values taken from climatological atlases and with seasonal variations considered. The grid size employed a final resolution of 1° intervals of latitude and longitude. Special finite difference nets were developed to resolve accurately the very fine structure which develops in the circulation patterns within regions of nongeostrophic flow at the Equator and along the side boundaries. Cal- culations were performed for a wide range of governing parameters; data obtained have provided researchers with a basic understanding of the physics of ocean circulation. An understanding of the Gulf Stream and similar cur- rents is basic to knowledge of the oceanic circulation. A simplified numerical model was used to determine the fac- tors that affect the path of the Gulf Stream and the vari- ations of observed transport. The model included both the effect of density structure and bottom topography. A sta- bility study also was performed to trace the origin of Gulf Stream meanders. A numerical approach to the stability calculation permitted extremely realistic profiles. Land-Sea Interaction Investigations were performed by the AOL during the last 2 years that involved an analysis of interaction phe- nomena at the land-sea interface, including the effects of wind, wave, tide, and currents and the development of pre- dictor equations for forecasting these phenomena. The AOL also conducted investigations that involved the development of field documentation and analysis of selected interaction phenomena at the land-sea interface to increase understanding of the effects of winds, waves, tides, and currents on beaches, inlets, and surface of the continental shelves; such investigations included the de- velopment of analytical expressions for the observed inter- actions and predictor equations for forecasting the selected interaction phenomena. In FY 69, AOL researchers obtained comprehensive movie-film data on the runup associated with breaking waves at Virginia Beach, Va. From an analysis of the data, theoretical equations for wave runup were developed. Re- searchers also studied the dispersal of sand grains by inlet currents at Rudee Inlet in Virginia Beach, using radioactive sand tracers and sand grains coated with fluorescent dye. Coincident with obtaining tracer release-and-recovery data, AOL scientists obtained data on net fluid force vectors in the study area. Sea-Air Interaction The direction of AOL research programs in sea-air inter- action during the last 2 years involved the study of exchange processes — heat, moisture, momentum, and mass — between the oceans and the atmosphere. Ocean-atmosphere inter- action studies were pursued in two distinct efforts — ^to de- velop better models and to provide better instrumentation. A numerical model was developed for the ocean-atmosphere Preparing salinity-temperature-depth (STD) sensor for lowering into the ocean. boundary layers which extend from depths of a few hundred meters in the ocean to heights of about a kilometer in the atmosphere. The principal processes included in the model are eddy fluxes in humidity- and salinity-dependent strati- fied flows, mixing caused by wind-generated waves at the sea surface, and cloud-dependent radiative heating. The interface conditions require continuity of eddy shearing stress, velocity, and temperature; saturation of the air; and balance between evaporation and salinity at the interface. Parallel to model development was a program for instru- ment development to improve measurements of all important parameters in the lower atmosphere which enter numerical model development. The instrumentation is designed to 90 observe wind speed, humidity, and temperatures. Tethered balloons carry the instruments aloft where they transmit data to a ship below through multiplexing techniques. Field data obtained as vertical profiles and time series were ana- lyzed by digital computers. A fast Fourier transform pro- gram was developed for the GFDL-1108 computer, permit- ting calculation of energy spectra and cospectra. The AOL's storm surge group is working on models in- volving storm-surge resonance phenomena with the passage of tropical storms traveling parallel to the coast. Using a geometric-optics technique for resonance modes, indications are that typical storms with a maximum wind radius on the order of 30 to 50 miles may be too large to generate pro- gressive edge waves as forecast by past theoretical work. Computer runs of models for storms with a maximum wind radius of 15 miles do show generation of progressive edge waves. A preliminary field project, the Atlantic Trade Wind Ex- periment (ATEX), was conducted near Barbados in the West Indies in February 1969, followed by the initial phases of BOMEX in May 1969. The Sea-Air Interaction Lab- oratory of AOL contributed significantly to both major field experiments. The Laboratory coordinated U.S. par- ticipation in ATEX. The USC&GS ship Discoverer carried out an intensive sea-air interaction program for ATEX in collaboration with two German — Planet and Meteor — ships and one British research vessel — Hydra. The four ships posi- tioned in a 400-mile triangular array southwest of the Cape Verde Islands, drifted with the tradewinds for 3 weeks in late January and early February of 1969, taking intensive samples of the lower atmosphere and upper ocean layers with specialized instrumentation to investigate tradewind inversion. Scientists from several countries and the United States participated aboard the Discoverer, conducting in- vestigations related to atmospheric electricity, radiation, chemical oceanography, and marine biology. The Laboratory also performed an observation program during the BOMEX project; this program involved an in- vestigation of the planetary boundary layers from ESSA's participating ships. Scientists also established a full surface observation program on the other participating research ships. Direct heat flux measurements were attempted, using recently developed instrumentation at Scripps Institution of Oceanography. The technique consists of observing radio- metrically the effective temperatures at two different levels very close to the sea surface, and applying molecular diffu- sion theory. Satellite photographs were used in the study of low-level convective cumulus cloud patterns in the eastern Caribbean Sea and western tropical Atlantic Ocean. These patterns were related to observations of temperature, pressure, wind, and other meteorological parameters obtained during ATEX and BOMEX. Ocean thermal data obtained by ESS A re- search vessels were correlated with Gulf Stream data ob- tained by Nimbus 2. TELECOMMUNICATIONS AND SPACE SERVICES The Telecommunications and Space Services of ESSA, rendered through its Research Laboratories (RL), provide descriptions and predictions of the state of the earth, its atmosphere, and surrounding space that are pertinent to electromagnetic wave propagation and its applications to telecommunication and remote sensing, as well as those pertinent to vehicular travel in the upper atmosphere (ion- osphere) and space. The electromagnetic spectrum is a limited resource that supports millions of telecommunication channels simul- taneously when used efficiently. Efficient use of the spectrum involves not only frequency sharing, but also sharing of time, space, polarization, and other factors. The term elec- trospace has been coined to designate all factors involved in efficient use of electromagnetic waves for telecommunica- tions. ESSA's Telecommunications and Space Services help users make more efficient use of the electrospace by pro- viding reports on actual radio conditions and predictions of expected conditions in the troposphere and ionosphere that distort, refract, and change the characteristics and strength of radio waves, and by providing research and consultative services on those aspects of telecommunica- tion systems design that are affected by environmental fac- tors and electrospace use considerations. Other parameters of the environment also affect the char- acteristics of radio waves. For example, meteorological parameters in the lower atmosphere — such as barometric pressure, temperature, and water vapor — affect the refrac- tivity of the atmosphere, and thus the direction of radio waves. The radio-reflecting ionosphere is modified by bombard- ment of solar X-rays, ultraviolet light, electrons, protons, and by disturbances in the earth's magnetic field. Certain ionospheric conditions enhance long-distance transmission of radio waves by reflection between the earth and ion- osphere; other ionospheric conditions hinder radio wave transmission or block certain communications circuits, re- quiring the user to shift to less efficient telecommunication systems. The RL have programs to measure the ionosphere through continuous solar and geophysical observations in the upper atmosphere and space. A series of radio quality and ionospheric condition pre- dictions are issued on a scheduled basis, varying from four per day to one per week. Ionospheric predictions of wave propagation conditions on a worldwide or regional basis are produced on a semimonthly and monthly schedule. Radio-circuit predictions as reported by RL are used extensively by the telecommunications industry throughout the world. These predictions are particularly important in this country because of the national expenditure of $20 billion annually in the telecommunications field. Users of ionospheric predictions include 2,200 Government organiza- tions and 1,200 commercial and general public subscribers. Transmission of radio waves by means of the troposphere is affected by weather and climate: Precipitation scatters and attenuates radio waves, especially at the higher fre- quencies; inversions may trap radio waves, causing en- hancement or attenuation depending upon the geometry involved; turbulence causes scatter of radio waves, but can be used to obtain transmissions for hundreds of miles be- yond the line of sight. The RL predictions of tropospheric radio propagation conditions are mainly in the form of equa- tions or computer programs involving parameters which relate to such environmental characteristics as refractive index gradient and dispersion, turbulence, precipitation, and terrain irregularities. The RL also provide forecasts and data on disturbances occurring in space and in the earth's upper atmosphere as a consequence of unusual electromagnetic and energetic particle radiation emitted from the sun. Disturbances on the sun, such as solar flares, are associated with the emission of large quantities of radiation in the optical, radio, and X-ray portions of the electromagnetic spectrum and the ejection into space of both energetic electrons and protons. Although the earth's atmosphere protects life on the sur- face of the earth from most of this high-energy solar radia- tion, such radiation presents hazards to both man and 91 92 equipment as man attempts to use the upper atmosphere and space environment for operation of supersonic aircraft and manned and unmanned spacecraft. Space disturbance forecasting includes prediction of impending solar activity and its effects; such forecasts require continuous monitor- ing of the sun at both optical and radio wavelengths, and also monitoring of ionospheric effects of solar activity. Like telecommunications disturbance forecasting, RL's Radiation Measurement and Forecasting Service is a recent outgrowth of research activity in this field. The research and development (R&D) activities of the RL in Telecommunications and Space Services involve the following research fields: telecommunications (environmen- tal factors in communications technology), aeronomy and upper atmosphere, and space environment. With the advent of space exploration during the past decade, the regions beyond the atmosphere have come under intensive investigation. Man is protected from danger- ous solar radiation by the shielding effects of the earth's atmosphere and magnetic field. However, at the planned operating altitudes (60,000 to 80,000 feet) of supersonic transports (SST) and for any manned and unmanned space flights, solar radiation must be monitored and predicted to protect man's health for operational functions and to main- tain communications between space vehicles and earth. To continue improvements of its operational service programs, ESSA's RL conduct various research programs into the physics and dynamics of the upper atmosphere and on those exceptional environmental phenomena that affect man's operation in the high altitudes and space environment. TELECOMMUNICATIONS Research programs in telecommunications necessitate ex- amination of all pertinent elements of the environment. Variations in environmental parameters cause variations in prediction conditions; therefore, telecommunications research not only includes use optimization of the radio spectrum, but to a large extent concerns itself with environ- mental change. These research programs relate to other programs of ESSA because of the importance attached to telecommunications in data acquisition and dissemination. Telecommunications research in ESSA is conducted with- in the RL by the Institute for Telecommunication Sciences (ITS) and the Wave Propagation Laboratory (WPL). The ITS serves as the central Federal agency for the acquisition, analysis, and dissemination of information on propagation of electromagnetic waves, on electromagnetic properties of the earth and its atmospheric environment, on dynamics of electromagnetic noise and interference, on information transmission and antennas, and on means for more effective use of the electromagnetic spectrum for tele- communications. The ITS also conducts research and provides research services to improve national utilization of the electromag- netic spectrum for telecommunications, to determine the effects of the earth's variable surface and changing atmos- phere upon telecommunications, and to broaden technical understanding of these environmental factors requiring national telecommunications policy decisions. The electromagnetic spectrum extends from radio to X-ray waves, with operational telecommunications conducted by users of channels between about 10,000 and 40 billion Hertz, the present limit of radio wave frequencies allocated by the International Telecommunications Union (ITU). The num- ber of channels this allocation provides, considering that an ordinary two-way telephone conversation requires two chan- nels of 3,000 Hertz each, is not great. The 40 billion Hertz now allocated represents 13 million channels, each 3,000 Hertz wide. With 200 million people in the United States and 3.5 billion people in the world at present, 13 million chan- nels may not be sufficient to meet the growing communica- tions demands of everyone. The need for more channels is critical. Improved utiliza- tion of this limited portion of the spectrum is the only available solution presently to overcrowding. However, en- vironmental research should permit eventual use of the spectrum range in the higher frequencies (shorter wave- lengths) as those environmental factors in the lower atmos- phere limiting use of the higher frequencies are overcome. One major objective of research in telecommunications is to develop and apply methods for optimizing use of specific portions of the radio spectrum, whether influenced by the ionosphere or by the troposphere and earth's terrain. These communications technology studies include, for ex- ample, research on multiplexing to enlarge the amount of information carried by a given channel and studies of improved cable communications as an alternative to broad- cast propagation methods. Ionospheric Telecommunications Program Work in ionospheric telecommunications was carried out in five major program areas: propagation of frequencies below 1.5 MegaHertz, high frequency propagation, modifi- cation of ionospheric currents, ionospheric predictions, and communications technology. Propagation of Frequencies Below 1.5 MegaHertz The objectives of research in propagation of frequencies below 1.5 MegaHertz are to devise and verify methods of predicting several environmental effects: Normal propaga- tion loss and phase delay of electromagnetic signals at fre- quencies less than about 1.5 MegaHertz as a function of frequency, direction of propagation, latitude, time of day, and season ; electrical constants of the ground and determina- tion of the appropriate ionosphere parameters for use in such predictions; and effects of natural ionospheric irregularities and other disturbances — such as those caused by solar flares, polar cap events, and nuclear explosions — on the propa- gation of signals of frequencies less than about 1.5 Mega- Hertz. Research was directed during the reporting period to- ward a variety of topics. Among the studies undertaken was one conducted aboard the USC&GS ship Oceanographer which yielded data on the daily variations of very low 93 frequency (VLF) signals, especially fading patterns caused by multimode interference. Another study, initiated for the Air Force, involved a series of measurements of ground- wave transmission loss at frequencies between 400 kiloHertz and 15 MegaHertz over path lengths up to 100 kilometers. Still another study was initiated in cooperation with the De- fense Atomic Support Agency (DASA) and involved a pulsed low frequency (LF) sky wave experiment to determine D-region ionospheric reflection coefficients as a function of frequency and, subsequently, D-region electron density pro- files. Investigations of ground-wave propagation over irregu- lar inhomogeneous terrain showed that frequently the effect of abrupt conductivity changes is masked by the effect of terrain changes. In FY 69, data on 40 atmospherics recorded simultaneous- ly in the United States and Japan were analyzed and ex- changed. Experimental evaluation of phase errors in long- range aid to navigation — ^Loran-D — radio navigation sys- tems was also carried out for the Air Force in FY 69. Theoretical evaluation of phase corrections for three-dimen- sional propagation over irregular terrain continued. High Frequency Propagation During the past 2 years, ITS scientists conducted theoreti- cal and experimental studies of radio signal propagation at frequencies from about 2 to 50 MegaHertz as part of the high frequency (HF) propagation telecommunication studies. These studies had the following objectives: to describe the variable characteristics in time and space of the ionosphere as an inhomogeneous, dynamic medium; to determine the effects of irregular terrain on the radiation, reflection, and scattering of radio signals; and to predict the frequency, time, and spatial characteristics of HF tele- communication signals. Ionospheric oscillations with a period of about 3 minutes have definitely been associated within a radius of about 200 kilometers with centers of severe weather indicated on weather-radar maps. Studies of the interaction of atmos- pheric waves with the ionosphere show that photochemical effects are as important as dynamical effects in the produc- tion of E-region irregularities. A coordinated HF propagation experiment was conducted from August 1966 through June 1968. Data were collected on 5 days of each month with several different observational techniques. Results include validation of the three-dimen- sional ray-tracing program as an accurate tool for simula- tion of ionospheric propagation, development of a technique for accurately estimating the range to a distant transmitter, and establishment of a relationship between the quality of radio direction-of-arrival determinations and the character- istics of ionospheric radar records made simultaneously. In FY 69, data from the 2-year coordinated ionospheric experiment were analyzed, an atlas of observed ionospheric backscatter radar records was being compiled, and a com- puter program was prepared involving simulated effects of traveling ionospheric disturbances. rr 1 • -~? Verlifiil-horizontal array of the ionospheric- radar receiver on Table Mountain (near Boul- der, Colo.), used with a radar transmitter for ionospheric and sea-state studies. 94 Modification of Ionospheric Currents Ten balloons were launched by Earth Sciences Labora- tories (ESL) scientists at Eielson Air Force Base near Fairbanks, Alaska, to determine the energy spectra of pre- cipitating electrons that modify the ionosphere conduction in auroral electro jet currents; data on three events of work- able magnitude were obtained. An understanding of the energy spectra of precipitating electrons will reveal to what extent micropulsations observed on the ground are attribu- table to modification of ionospheric currents caused by in- creased conductivity brought about in the particle bombard- ment process. Ionospheric Predictions The preparation and dissemination of ionospheric pre- dictions and data for military and civilian radio; for scien- tific uses in satellite, missile, and space programs; and for other scientific and engineering applications are performed by ITS. Ionospheric data are obtained from cooperating ionosphere-sounding stations in this country and abroad, and from stations operated by program personnel or through contracts. The RL and other Federal agencies use ionos- pheric predictions to provide experimental transmissions or engineering services, to improve prediction methods, and to apply predictions to their requirements. Numerical mapping techniques for predicting the global variations of the ionosphere were extended to include seasonal and sunspot cycle variations. Similar numerical techniques were applied to sporadic E — a thin layer in the lower part of the ionosphere whose erratic occurrence results in uncertain propagation of radio signals reflected from the ionosphere. In FY 69, three-dimensional prototype electron density maps were prepared. An improved method of updating regu- lar monthly predictions of ionosphere characteristics was also accomplished. Improvements in systems performance prediction were made through investigation of ionospheric absorption, antenna gain, propagation mechanisms, signal- to-noise thresholds, and short-term predictions. Major advances were made in the computer-programmed prediction model employing the ionospheric parabolic-layer theory used for communications planning and operational purposes in all military services. Improvements were also made in the calculation of the radio transmission loss by taking into account a winter anomaly and changes in absorption with latitude. Communications Technology Beneficial technical information to improve telecommuni- cations and to make fuller use of the radio frequency spec- trum within the ionospheric modes of propagation became available during the reporting period. Advancement in technical information was the result of basic and applied research in the fields of antennas and information trans- mission and the design and evaluation of telecommunica- tion equipment and systems. Technical data, services, and recommendations on the Nation's ionospheric telecommuni- cations activities were provided to industrial, governmental, and scientific organizations by ITS. A laboratory instrument which accurately simulates the effects of the ionosphere on a propagated signal was com- pleted in FY 69. The mathematical model which was the basis for the instrument has been validated by comparison with measurements over actual ionospheric paths. A model and simulator for HF atmospheric radio noise was also developed and integrated with the ionospheric simulator during FY 69. These simulators permit communication equipment to be laboratory-tested, minimizing the need for expensive field testing. A major effort during the past 2 years was devoted to the development of a system for predicting short-term varia- tions in ionospheric telecommunications performance, with initial emphasis placed on detection, warning, and predic- tion of effects associated with solar disturbances. In FY 69, additional communication-oriented parameters were included in the short-term forecasts through further study of users' requirements ; direct user access to the timesharing computer was also provided. On July 1, 1968, the Telecommunications Disturbance Forecast Center at Fort Belvoir, Va., was replaced by a real-time system which used a timesharing computer at Boulder, Colo., to forecast the probability, time of occur- rence, duration, and magnitude of short wave fadeouts, polar cap absorption events, and magnetic storms and their effects on telecommunications systems. An investigation of ways to provide a nonradiating com- munication link for use on moving high-speed railroad trains was undertaken for the Department of Transportation (DOT). Promising results were obtained with the so-called Goubau or "G" line, a one-wire line on which energy propagates in a surface-wave mode of low attenuation. The method devised was field-tested to determine the effects of severe weather and other environmental factors, line-coupling devices, and line supports on the performance of the system. A search continued in FY 69 for better theoretical re- ceivers, given time-varying specular and scatter multipath fading models. Verification of the modulation effect on the spectral re- sponse of radar return pulses in clutter was made for the special case of one resonant scatterer among many non- resonant scatters. A systems plan was prepared in FY 69 for the development stage of the Integrated Global Ocean Station System (IGOSS). This System will provide communication of meteorological and oceanographic data from buoys in the open sea to shore locations. 95 P^ illli.Pw» '^ m ^^ fjt . -' . .-.-J '-■ ,'---- .. ).■*• A surface-wave launcher used to transfer radio frequency signal energy from conventional coaxial cable to the surface-wave line. Tropospheric Telecommunications Program Work in tropospheric telecommunications was carried out in six major program areas: information transmission and analysis, tropospheric systems design and performance, electromagnetic interference environment, tropospheric propagation predictions, spectrum utilization research, and tropospheric physics. Information Transmission and Analysis The information transmission and analysis program is concerned with developing techniques and instrumentation for measurement, analysis, and laboratory simulation of tropospheric communication channel characteristics. These techniques and instrumentation provide an economical and reproducible way of evaluating in the laboratory the effects of channel characteristics and antenna diversity arrange- ments on information transmission and the performance of modulation-demodulation systems. Channel characterization measurements for wideband frequency-modulation and frequency-division-multiplexing systems were begun during FY 68, using a pseudorandom analog test signal to develop the transfer function of the test channel for both amplitude and phase characteristics. High-speed digital time-series analysis was utilized to de- velop the statistical behavior of the channel characteristics for laboratory channel simulation. During the reporting period, a considerable amount of channel characterization data was obtained over tropospheric circuits operating in line-of-sight, diffraction, and scatter modes of propagation on wideband communication circuits in Western Europe and Southeast Asia. Performance index data for both voice and data operation were obtained simul- taneously with the characterization and propagation data collection. Several improvements in data processing and analysis sys- tems were formulated in FY 69 to effect an interface of special-purpose analysis instrumentation with general-pur- pose digital computer systems in the RL's Computer Di- vision. 96 Tropospheric Systems Design and Performance The design and performance analysis of telecommunica- tion systems operating in the troposphere include taking account of the characteristics of the medium, presence of other signals (natural and manmade noise), type of modu- lation, and characteristics of the terminal equipment. Such systems usually involve electromagnetic propagation along the earth's surface and through the atmosphere, but they may also include cable transmission or acoustic propagation. An important part of theoretical research and experimental application involves the study of modulation techniques best suited for particular systems. Among the research efforts pursued by ITS scientists is a project to permit more efficient use of educational tele- vision and radio channels. Time-diversion and frequency- division multiplexing can substantially enlarge the amount of information carried by a given channel. By employing a variety of subchannel modulation techniques, simultaneous transmission of analog and digital data is permitted and signal-to-noise ratios are improved. The design of a digital communication system for the National Crime Information Center of the Federal Bureau of Investigation was undertaken. This system links large digital computers throughout the Nation, permitting ready access to vital law enforcement data. Electromagnetic Interference Environment Studies which define quantitatively the characteristics of the electromagnetic interference environment arising from natural and manmade radio noise and unwanted signals are conducted by ITS. Information is provided on the environ- mental influences affecting systems for improving practices of spectrum conservation and utilization. During the past 2 years, methods were developed for making theoretical studies of the effect of radio noise on the reliability of digital telecommunication systems that also permitted the evaluation of error rates for particular systems operating in the presence of both atmospheric and manmade noise. Mathematical modeling was developed to obtain statistics of the noise process for use in predicting systems performance. Additional verification, using a broader range of noise samples, was required for confidence in the model. To obtain noise samples from which the various needed statistics were found, a development program provided a laboratory recorder which operated in communication band- widths and over large dynamic ranges to permit using the recorded noise samples for noise analysis purposes and for systems testing in a channel simulator. A specially equipped mobile noise laboratory was used for studying manmade radio noise. The upper frequency limit of its radio noise measurement capability was extended to 250 MegaHertz with the addition of channels at 100 and --^5^. :«» One element of a two-dimensional antenna array used in a study of the random distortion of wave fronts of signals propagated through the turbulent atmosphere. 97 250 MegaHertz; work was started on equipment to extend the frequency range further into the ultrahigh frequency (UHF) portion of the spectrum. Using the mobile noise laboratory, manmade radio noise data were collected and analyzed for the writing of a computer program to provide correlation of noise data with population and vehicle densi- ties. Studies are continuing on ways to determine applicable predictors for estimates of the manmade noise parameters required for systems designed to overcome radio and tele- vision interference. Tropospheric Propagation Predictions Programs in tropospheric propagation predictions during the reporting period involved the development of physical and mathematical models for predicting the performance of tropospheric telecommunications. A tropospheric propaga- tion prediction model that covers a wide range of frequency, distance, antenna height, and terrain types was tested and revised by ITS scientists to obtain improved agreement with data from an extensive field measurement program. The model is used to predict and evaluate the performance of communication networks. Theoretical studies to calculate effective reflections of the complicated structure of electromagnetic fields above irregu- lar terrain were underway and mathematical models were being developed that adequately fit the actual situation. Another project involved the development of a mathe- matical model to describe the scattering of radio waves by precipitation in clouds and predicted the resulting interfer- ence between satellite and terrestrial telecommunication systems sharing the same radio frequency. Additional projects were underway, including a study of the characterization of radio channels and the information capacity of telecommunication systems, and a study to de- velop and test a program to simulate pulse code modulation (PCM) systems. Spectrum Utilization Research Research in spectrum utilization focuses on the develop- ment and application of theoretical and experimental meth- ods to make optimal use of those specific portions of the radio spectrum primarily influenced by the troposphere and by terrain. Within this ITS program, three subprograms of research are pursued: terrain effects and tropospheric point-to-point communication systems, atmospheric effects on microwave communications systems, and frequency- sharing and spectrum utilization problems. To aid ITS's Tropospheric Propagation Predictions Group in the determination of transmission loss, analyses of ex- tensive propagation measurement results over irregular terrain at frequencies between 20 MegaHertz and 10 Giga- Hertz were performed and supplied in FY 68. Analyses of data obtained from a microwave link in Ohio suggest the possibility of prediction fading from synoptic weather in- formation; studies were undertaken to explain the absence of significant distortion of nanosecond pulses observed over a line-of-sight link. Frequency-sharing studies were made between land mo- bile and television broadcasting; a mathematical model was developed to study the difference of path-to-path correlation in irregular terrain between broadcast and land mobile operations. Extensive support was provided to the Department of Defense (DOD) agencies in tests and evaluations of wide- band communication links in Southeast Asia and in Europe during FY 68. Further assistance was provided by the ITS to DOD agencies in connection with the design, installation, and testing of wideband communication links throughout the world, including work on performance standards, methods of data collection, and tests of angular diversity performance for the Army Strategic Communications Command. Tropospheric Physics Tropospheric physics studies include research on the effects of the troposphere on the propagation of electromag- netic waves at frequencies above 300 MegaHertz. Emphasis in research is placed on the signal-phase distortion imposed by the atmospheric medium, on the evaluation of limits im- posed by atmospheric turbulence on the accuracy of rocket- and satellite-tracking systems, and on the accuracy deter- mination of electromagnetic distance- and angle-measuring systems used in geodesy and seismology through studies of the tropospheric refractive index structure. Techniques are also developed for phase stabilization over tropospheric scatter, line-of-sight, and satellite relay paths. During the reporting period, research was underway on the analysis and interpretation of data obtained in a series of 10 major propagation experiments designed to study several types of atmospheric errors in missile- and satellite- tracking systems. These experiments were sponsored jointly with the Air Force's Electronic Systems Division, the Avionics Laboratory, and the Cambridge Research Labora- tory. Personnel of the ITS's Tropospheric Physics Group par- ticipated with the Millimeter Wave Propagation Group of the WPL in an experimental determination of the usefulness of millimeter-wave sky temperature data as refraction error correctors in radio-tracking measurements. The experiments included side-by-side operation of several radiometers and concurrent-range variation measurements over the slanted 65-kilometer ocean path in Hawaii previously used in ex- periments during 1967. An investigation was made into the correlation between phase-of-arrival variations observed in the slanted-path, radio-tracking configuration and the corresponding spatial variations in atmospheric refractive index observed with an airborne microwave refractometer. Theoretical research at the University of Michigan has predicted a useful correla- tion of these two variables. The first measurements to test the theory were made in April 1968 over the same slanted 65-kilometer path in Hawaii. In conjunction with the Hawaii field tests, experiments were conducted to determine the effects of radio frequency separation on the relative behavior of phase and amplitude fluctuations of signals propagated through the troposphere. These experiments were conducted 98 Adjusting the receiving instrumentation used in radio-optical dispersion studies in the vicinity of Boulder, Colo. in response to the increasing need for basic information to use in designing high-rate digital-type telecommunication systems. The results were subjected to cross-spectrum and coherence analysis to provide a comprehensive comparison of phase and amplitude characteristics at two closely spaced microwave frequencies. Environmental Factors for Communications and Remote Sensing The WPL acts as the focal point for wave propagation research aimed at the extension of telecommunication capa- bilities into higher frequencies, including optical waves, and develops new applications for electromagnetic remote sens- ing of the geophysical environment. Laboratory research concentrates on studies of telecommunication capabilities, frequency limitations, remote sensing techniques, and sound wave propagation in the atmosphere. Optical Wave Propagation Theoretical and experimental studies of the interaction of electromagnetic waves at optical and near infrared fre- quencies with the lower atmosphere included investigation of the usefulness of these frequencies for telecommunication purposes and as a means for remotely sensing the physical properties of the atmosphere. Observations of atmospheric amplitude scintillation, beam spread, and beam wander of a 0.63-micron laser source were completed over horizontal paths from 5 to 145 kilometers during the reporting period by WPL. In another study, simultaneous measurement of laser beam scintillation and atmospheric turbulence revealed that the intensity scintillations saturate and do not increase above a certain maximum value even though the turbulence con- tinues to increase. In FY 69, the intensity scintillation saturation phenomenon was further investigated. Scintilla- tion and beam spread measurements of a 10.6-micron source 99 were carried out, and the longitudinal and transverse phase fluctuations in visible and infrared beams caused by the atmosphere were measured. A two-color distance-measuring instrument was improved to increase its range and accuracy; an accuracy of 3 parts in 10' in optical path length measurement has been achieved over a 5-kilometer path. It is planned to employ the instru- ment for earth strain measurements in the vicinity of Den- ver, Colo., and elsewhere. Construction was started on a three-wavelength distance- measuring instrument capable of measurements to an ac- curacy of a few parts in 10^ over path lengths greater than 50 kilometers. SUBMILLIMETER WaVE PROPAGATION Theoretical research, both laboratory and field, was con- ducted during FY 68 and FY 69 in WPL on the use of millimeter, submillimeter, and far infrared wavelength elec- tromagnetic waves (ranging from 10^^ to 10^* Hertz) for telecommunications and remote sensing of the geophysical environment. More precise knowledge of atmospheric at- tenuation characteristics of water vapor, carbon dioxide, and nitrous oxide bands in the 1- to 25-micron range was obtained. The effect of line shapes on the continuum of water vapor absorption has been compared with recent data to describe attenuation over long paths. The HCN and H2O lasers have been designed, constructed, and placed in operation to provide sources of submillimeter waves. Detectors and mixers employing a new open struc- ture have been developed; signals from the HCN laser have been mixed together with a harmonic of a 70-Giga- Hertz klystron. Millimeter Wave Propagation Millimeter wave propagation research — theoretical and experimental — involves the interaction of millimeter waves with the lower atmosphere for telecommunications and re- mote sensing. Measurements of noise emission from Colorado thunder- storm cells at 10.7 and 4.9 GigaHertz were made and ana- lyzed to obtain an estimate of the line integral of liquid water content of storms. Atmospheric emission and solar radiation near 15, 31, and 53 GigaHertz were measured in Colorado and Hawaii for use in attenuation studies. The 53-GigaHertz data were also used for inferring temperature profiles in the atmosphere, using numerical integration techniques developed from theory for this purpose. During FY 69, theoretical and experimental work con- tinued in WPL to improve the radiometric technique for obtaining refraction corrections for missile-tracking systems. Preliminary studies, supported by the National Environ- mental Satellite Center (NESC), were carried out to deter- mine the spectral intervals that could be used to measure surface conditions and vertical profiles of temperature, humidity, precipitable water, and water content of clouds from satellites. Closed effects on the various sensing tech- niques were emphasized. Radio Meteorology Studies on the interaction of microwave and lower radio frequencies with the lower atmosphere to facilitate radio telecommunications and to develop new remote sensing techniques continued during the past 2 years. Under study were atmospheric turbulence and structure and their rela- tions to electromagnetic propagation and atmospheric dy- namics. A direct technique for determining evaporation with a microwave refractometer and sonic anemometer was devel- oped in WPL. This instrument was used to assist the De- partment of the Interior's Bureau of Reclamation in meas- uring the effectiveness of monomolecular layers in reducing evaporation from reservoirs. A parallel development was made of an optical/microwave instrument to measure at- mospheric water vapor remotely over paths more than 10 kilometers long. The program of investigating interference fields by moni- toring very high frequency (VHF) and UHF broadcasts was continued. Fine-scale atmospheric structure and con- current synoptic weather over radio paths were measured. Meteorological Doppler Radar Studies of atmospheric phenomena by means of micro- wave pulse Doppler radar techniques capable of sensing the motion of atmospheric targets were underway. Particular emphasis in research conducted by WPL was placed upon detailed studies of severe convective storm dynamics (by simultaneous use of two or three Doppler radars observing the same storm from different locations), of mesoscale par- ticle motion field in widespread storms, and of atmospheric turbulence. The design and fabrication of the first two mobile X-band Doppler radar were completed, and fabrication of a third has been started. The dual radar system was used in studies of wind field dynamics in the low levels of convective storms and in the study of wind field patterns, associated con- vergence, and vorticity inside stratified storms as related to the precipitation mechanism. Other studies conducted included observations made of the wind field inside snowstorms in Boulder, space and time variability of particle motion inside several convec- tive storms, experimental forest fire kinematics, and feasi- bility of using "chaff" dipoles to study clear air motion. Signal processing methods, based on the use of a digital computer programmed with fast Fourier transform algo- rithms, were also developed during the reporting period. Geoacoustics Research Research involving theoretical studies and experimental measurements was conducted on the generation and propa- gation of infrasonic waves through the atmosphere and on the interaction between infrasonic waves and other geo- physical phenomena. Results of such WPL research are used as a basis for deducing certain fundamental physical properties of the atmosphere, earth, and oceans. 100 Two new infrasonics stations were completed at Palmer, Alaska, and at Pullman, Wash., bringing the total number to seven stations operating in North America, South Amer- ica, and the Middle East. Each station records the wave- forms of sound waves that range in oscillation periods from 1 to 1,000 seconds; from these waveforms, the strength, azimuth of propagation, and horizontal trace velocity are determined. In addition to infrasonic equipment, the Washington, D.C., station includes a 4-element array of short-period ver- tical seismometers, permitting direct comparison of Rayleigh waves with the infrasound they generate. Observations of various geophysical sources were con- tinued. The June 1968 explosion of the Caldera on Isla Fernandina in the Galapagos Islands produced readily measurable infrasound at North and South American in- frasonic stations. Record waveforms are still being studied to evaluate the propagation of infrasound in the atmosphere. AERONOMY AND UPPER ATMOSPHERE In upper atmosphere research, basic knowledge is sought about the physical principles governing the formation and behavior of the ionized portions of the earth's environ- ment and its relations to other parts of the environment. The subjects of study include programs in molecular and atomic collision processes in the atmosphere, ionospheric conditions peculiar to the area of the magnetic equator, airglow and aurora activity, geomagnetic behavior of the upper atmosphere, meteorology of the upper stratosphere, and propagation of radio waves in ionized media of all types. Research and Development Programs The bulk of the research programs are conducted by the RL's Aeronomy Laboratory (AL) [meteorology of the upper atmosphere is conducted by the RL's Air Resources Laboratories (ARL)], and involve primarily the predic- tion and control of those portions of the environment re- quired to fill the telecommunications and space needs. Laboratory Plasma Physics Research in laboratory and theoretical plasma physics was conducted and applied to plasma problems peculiar to studies of geophysical phenomena. Emphasis in this AL research program was placed on those aspects of plasma physics that are not adequate understood. Research on the theory of wave scattering, correlation functions, and nonlinear processes, including turbulence and transport coefficients, was undertaken. This research related diffusion to laboratory measurements of the cor- relation of density fluctuations. A new turbulence theory based on plasma physics rather than neutral gas physics was developed during FY 69; this theory offered considerable promise for predicting the ef- fects of ionospheric turbulence on the propagation of radio and radar waves. Such turbulence can enhance radio com- munications on earth by scatter propagation or can degrade communications with space vehicles. Atmospheric Collision Processes Both experimental and theoretical basic research on atomic and molecular processes, pertinent to the earth's atmosphere, continued in AL during the past 2 years with the development and application of techniques for measur- ing ionospheric ion-neutral reactions. The atmospheric D- region negative ion-reaction studies were extended, lead- ing to predictions that NO 3 would be a dominant ion. Tem- perature dependences of ionospheric rate constants were measured from 80° to 600° Kelvin. Atmospheric reactions of the metal ions— Fe+, Mg+, Ca+, Na+, K+— and of Si+ have also been measured; a scheme of E-region metal ion chemistry was developed and applied to the problem of ionospheric sporadic-E layers. The first laboratory measure- ment of an ion with an electronically excited neutral was also accomplished. Broad studies of ionospheric positive and negative ion- neutral reactions continued during FY 69. The reaction scheme which produces the major D-region positive ions, H-,02+ and HsO+, below 80-kilometer altitude was discov- ered; these reactions are now included in models of posi- tive ion D-region chemistry. Water cluster ions are pro- duced in sequences commencing with t production. These and other studies conducted with this unique laboratory technique have developed strong evidence that the ob- served water cluster ions in the high atmosphere cannot be entirely explained as rocket contamination, an impor- tant implication for understanding the chemistry of the ionospheric D-region. Rocket and Satellite Studies Rockets and satellites were used in AL research investi- gations on the ionosphere and exosphere. The aim of these probes was to extend knowledge of the composition and dynamics of both of those spheres, of the plasma phenom- ena, and of such other processes as the interactions be- tween rockets and satellites and the ionospheric and exo- spheric plasma. Among the research results derived during the report- ing period were: A method that obtains very precise values from topside sounder data for electron density and tem- perature; a new theory that explains radio frequency reso- nances as delayed echoes; an atomic oxygen detector that is based on thin film detection techniques; and a theory for probes that takes into account the effects of electric charge on the satellite. Preparations of several rocket payloads for investigating polar cap absorption events were also undertaken. Studies of the dynamics of the topside ionosphere under disturbed conditions were undertaken; theoretical studies of the properties of radio frequency resonances observed in the ionosphere were continued; and a digital display sys- tem, complete with buffer and interface, to aid in the analy- 101 sis of topside ionosphere and other satellite data was fab- ricated. The newly developed atomic oxygen detector was flown and additional techniques will be developed for detecting other minor atmospheric constituents. Rocket flights into a polar cap absorption event were conducted to deter- mine the physical processes causing this phenomenon and to determine electron density loss processes. Scatter Radar Studies Incoherent scatter and other observing techniques were used in studies of aeronomy and plasma physics of the equatorial ionosphere conducted at the Jicamarca Scatter Radar Observatory near Lima, Peru. By employing a refinement of the Thomson scatter-observ- ing technique, a technique was developed by AL scientists for direct measurements of vertical drifts of the ionosphere. The monitoring of these drifts constituted a breakthrough, in that the east-west electric field propelling these drifts can now be studied continuously from the ground instead of through brief rocket observations obtained only during twilight hours; drift measurements are directly interpretable as electric field measurements. Comparisons with simultaneous satellite measurements of electron temperature revealed some remarkable discrep- ancies. The satellite Langmuir probe results indicated tem- peratures about twice as large as those measured by the incoherent scatter technique. Measurements of neutral tem- perature, made at Jicamarca, also provided details of di- urnal and solar-activity variation of F-region neutral tem- peratures that differed from satellite results; additional evi- dence has indicated that the incoherent scatter results are reliable. During FY 69, the AL conducted studies to detect minute changes in the direction of the geomagnetic field. Measure- ments of the lunar albedo were made, along with systematic monitoring of electron density and temperature and of ion temperature and composition. Meteorology of the Upper Stratosphere Ionospheric drifts and their relationship to the motion of neutral air were studied by a scientist from the ARL, based on measurements taken from Birdlings Flat, New Zealand, during the reporting period. The partial reflection method used at Birdlings Flat supplied data at 4-kilometer intervals within the 64- to 108-kilometer height range; these data were compared with meteor wind measurements, chem- ical release trails, and general circulation models. Of special interest to ARL scientists were analyses of in- dividual ionospheric drift profiles. From velocity curves separated by short-time intervals (40 to 115 minutes), vari- ous features attributed to gravity wave motions could be inferred. A train of gravity waves was assumed to exist in the 80- to 110-kilometer region, with the vertical wave- length of 12 kilometers and a period of 1 to 2 hours. When this model was interpreted in terms of changes observed in drift profiles, the results indeed suggested the presence of gravity waves. The vertical wavelength implied by ion- ospheric data was 10 to 12 kilometers, while the period could be either 80 to 150 minutes or 46 to 77 minutes. Results of this ARL study were consistent with the wind interpretation of drifts. In seasonal averages, the motions implied by ionospheric drifts closely resemble movements of the neutral air. HEIGHT-ADJUSTED PROFILES B=BIRDLINGS FL =WALLOPS IS. AT=ADELAIDE fp=ASlDE } PREVAILING WIND ■ TOTAL OBSERVED WIND M/SEC Comparson of ionospheric drifts from Birdlings Flat, New Zealand, with neutral wind measurements at various sites for winter 1964 (curve B) and for miscellaneous winter periods. 102 Optical Aeronomy Observations and interpretation of optical wavelength emissions from the upper atmosphere and interplanetary space were included in the AL research program during the past 2 years. The AL conducted specific studies of polar cap auroras by means of scanning spectrophotometers at McMurdo Sound, Antarctica, and aboard a National Aero- nautics and Space Administration (NASA) aircraft in the Northern Hemisphere. The same instrument was used to observe emissions at twilight. These studies yielded val- uable data relating to global atmospheric dynamics. Studies of stable red arcs and observations of sodium dayglow and twilight continued. Auroral radar was used to investigate variation of aspect sensitivities with azimuth and with rates of growth and decay of reflecting centers. SPACE ENVIRONMENT The major effort in space environment research is placed on studies conducted by the RL's Space Disturbances Lab- oratory (SDL) of solar activity and its influence on ter- restrial events. The study of solar flares is particularly im- portant because these flares often eject proton streams which affect radio-reflecting characteristics of the ionos- phere in polar regions and auroral activity. Telecommuni- cations, supersonic transport (SST) flights, and men and machines in space can also be seriously affected by these events. The SDL monitors and predicts fluctuations and disturb- ances in the earth's space environment associated with solar activity, and interactions with the lower atmosphere. These disturbances have important implications to man's utiliza- tion of the upper atmosphere and space. The Space Disturbance Forecast Center (SDFC) at Boul- der provides a forecasting and warning service for solar flares and proton events which affect the Nation's tele- communications, electrical power transmissions, and space flight activities. Solar observing station at the Space Disturbance Forecast Center, Boulder, Colo., for observing the sun in white light and selected narrow spectral regions. 103 Research and Development Programs Research programs on solar activity are essential for making possible more accurate forecasts of radiation haz- ards in space and the upper atmosphere and for determin- ing the effect of radiation on telecommunication systems. Research is also aimed at understanding the space dis- turbances and their originating mechanisms, and at in- creasing the reliability and accuracy in monitoring and fore- casting space weather. Solar Energetic Particles Physical mechanisms governing the energetic-particle en- vironment were investigated during the reporting period, with particular emphasis placed on the precipitation of particles into the atmosphere and their consequent ion- ospheric effects. Models of ionosphere responses were de- veloped for D-region electron loss processes. Measurement of the temperature coefficient for the major F-region ion- loss mechanisms was also made. Rocket-sounding techniques were investigated by SDL for use in direct measurement of parameters of the ener- getic-particle flux and of the disturbed ionosphere. During FY 68, four photometric payloads were flown from Fort Churchill, Canada, on SKUA rockets. Research during FY 68 indicated that midday recoveries during polar cap absorption events probably resulted from a change of pitch angle distribution of the bombarding solar cosmic rays. During FY 69, the northern end of a conjugate auroral radar experiment was operated from Anchorage, Alaska, and very high frequency (VHF) ionospheric absorption/ emission experiment was conducted at College, Alaska. Magnetosphere Theoretical and observational methods were employed by SDL to study the interaction of constantly streaming solar plasma with the geomagnetic cavity; mechanisms and magnitude of energy transfer through the magnetopause; time-dependent behavior of flare-generated shock waves; and plasma-wave generation and propagation in the tran- sition region and magnetopause. Data from the chain of riometer-observing sites being operated by the Space Dis- turbances Monitoring Facility of SDL were used to define geomagnetic field topology and geomagnetic cutoff energies at high latitudes. Studies of auroral absorption events, their global move- ments, conjugate properties, and relationship to phenomena observed in space by satellites were directed toward ex- plaining the properties and behavior of auroral particle precipitation. A description of the steady-state plasma flow field be- tween the earth's bow shock wave and the magnetosphere boundary was given. The magnetosphere boundary location was verified, using observations from the Pioneer 7 sat- ellite. Theoretical simultaneous flow directions in the magneto- sheath were verified by Vela observations. With regard to the influence of the geomagnetic tail on the precipitation of solar protons, the calculated magnetic cutoff latitudes agreed with observations to a higher degree of accuracy than any previously estimated. During FY 69, several theoretical models of magneto- spheric plasma flow were tested by incorporating solutions of hypersonic flow of a continuum gas past a blunted obsta- cle which represented the magnetosphere. Both steady-state and time-dependent solutions were examined. Auroral precipitation studies were continued, with im- mediate attention focused on conjugate properties — spe- cifically on displacement of conjugate points from their computed positions — and on hemispheric differences in the intensity of the particle precipitation. Disturbed Ionosphere Short-term (less than hourly) changes in the electron density structure of the atmosphere and in the incidence of solar X-rays and extreme ultraviolet radiation on the earth's atmosphere were investigated using radio wave tech- niques. In FY 68, investigations showed that during certain flares much of the enhanced ionization above the 100-kilo- meter level is produced by solar extreme-ultraviolet rather than X-radiation. Acoustic waves — ^those waves with a frequency greater than the natural frequency of oscillation of the atmosphere — with periods that range from 20 seconds to about 5 min- utes were observed in the F-region, having originated from nuclear explosions, severe weather fronts, and unknown sources. Continuous observations of traveling disturbances in the Antarctic ionosphere have been made since December 1967. During FY 69, SDL conducted research on solar flare spectra, comparing the spectra deduced from the ionosphere with those observed by satellite-borne sensors. A study of acoustic waves generated by severe weather systems and their propagation characteristics was also made, and analy- ses of Antarctic records were continued. Investigations into the excited states of the oxygen atom, characteristic of regions from 100- to 400-kilometers, were conducted during the past 2 years with optical observations accomplished from the ground and from rockets. Problems involved in these investigations were also studied theo- retically to determine the measurements of most importance and to examine the detailed effects of these excited states on the chemistry of the atmosphere. Current efforts are directed toward obtaining a height profile of excited Oo. Four photometric rockets were fired during the reporting period to obtain the excited oxygen profile in the upper almosT:)here. A study of the ionosphere and exosphere electron content, using radio beacon data from the eccentric Orbiting Geo- physical Observatory fOGO) satellites, continued: the ob- jective of this study was to present an integrated review of all observations and their interpretations. 104 Solar Physics Rapid presentation of concise and informative flare data was improved through comparison of flare, sunspot, and plage observations gathered from different solar observa- tories. Relatively large horizontal motions of small elements have been seen in the undisturbed chromosphere, but these motions are dominated by less frequent but larger elements and movements in active regions. This observation, the re- sult of a preliminary SDL study of high-resolution solar films in area, time, and wavelength, identified new areas for research in solar activity. Considerable progress has been made toward perfecting ground-based radio techniques for the study and regular observation of irregularities in solar wind. These irregu- larities, moving radially outward from the sun at some 300 kilometers per second, cause scintillation (or "twink- ling") of certain small-diameter flare-associated radio sources. Work on a rapid-response one-dimensional radiohelio- graph continued. Tests were performed with an electronic correlator to synthesize 48 simultaneous fan beams in a nar- row section centered on the sun. This device will eventually permit the accurate location of flare-associated radio bursts. Synoptic Geophysical Measurements Research conducted jointly by SDL with DOD's Ad- vanced Research Projects Agency (ARPA) for the pur- pose of developing advanced methods to detect effects of high-altitude nuclear detonations was completed during FY 69. The observational portion of this research pro- gram involved the simultaneous recording on digital mag- netic tape of the output of approximately 20 geophysical sensors. These sensors provided data on the ionosphere (including very low frequency (VLF), low frequency (LF), and high frequency (HF) signals propagating over various paths), geomagnetic field, solar noise intensity, infrasonic signals, and atmospherics from thunderstorm activity. An on-line computer was used to process the data before re- cording and to provide automatic detection of sudden ion- ospheric disturbances (SID) for use in the SDFC. Data were retrieved from magnetic tapes by microfilm plotting; processing was applied to the data before they were plotted. Multisensor data were used to investigate: (1) relation- ship between the various sensor responses following such distant occurrences as nuclear explosions, strong auroral activities, and volcano eruptions; (2) possible connection between tornadoes and certain types of changes in ion- ospheric propagation; (3) correlation between distant se- vere storms and arrival statistics of atmospherics signals; and (4) ionospheric changes which occur during SIDs and how they relate to solar X-ray emission. The efficiency of this computerized system to detect SIDs was found to be very good when compared to the conventional techniques which use reports from a large number of independent observing stations. The SDL also developed methods to in- dicate indices of activity for the ionosphere, geomagnetic field, and thunderstorms in real-time. Forecast Techniques Forecasting techniques research by SDL centered on the development of objective forecast formulas by sta- tistical analyses and the use of numerical methods for elec- tronic computers. During the reporting period, methods to verify many of the forecasts prepared by the SDFC were perfected. Several alternative methods of scoring the fore- casts are now in use; verifications occur on a regular basis. Instrumentation and Data Services The Instrumentation Group of SDL provides general support to the Laboratory through the design and construc- tion of special-purpose instrumentation; the Group also undertakes related work at the request of other ESSA com- ponents and Government agency groups. During FY 68, the Group maintained the instrumentation used by the SDFC in Boulder and had a special responsibility for planning and organizing data acquisition from satellites, for sup- porting ARPA-funded programs with geophysical sensors and interface equipment for the on-line computation system at the Table Mountain Electromagnetic Reception Site near Boulder, and for designing and constructing sounding-rocket instrumentation to measure polar cap absorption phenomena at high latitude in support of the Ionosphere Response Project. Noteworthy individual projects completed in FY 69 included an automatic system for measuring ionosphere total electron content by means of the Faraday rotation of radio signals received from geostationary satellites, and new sounding-rocket photometer instrumentation. Geophysical data were collected, reduced, and analyzed for the SDL during the past 2 years. These data taken in Antarctica, Canada, Iceland, and Alaska were digitally re- corded in most cases. A network of geophysical sensors was set up throughout Alaska to provide real-time input to a digital computer at the Anchorage Space Disturbances Monitoring Facility. The computer automatically alerts the SDFC whenever significant geophysical events occur; in ad- dition, the computer sends detailed digital data to Boulder daily for scientific analysis. Space Disturbances Forecast Services During FY 68, the Global Solar Flare Patrol Network was completed. A small computer was installed in the SDFC at Boulder to interface with the Anchorage Space Dis- turbances Monitoring Facility computer which automatically handles the analysis and transmission of solar activity data and warnings. The installation of the optical telescope has improved the quality and quantity of the Boulder solar monitoring. Solar flare forecasts and warnings are dis- tributed nationally and internationally by station WWV and VHF radio transmissions, from World Meteorological Organization (WMO) terminals, and through foreign re- gional warning centers. 8 ENVIRONMENTAL Service Programs The National Environmental Satellite Center (NESC), one of the five Major Line Components (MLC) of ESSA, has the responsibility for the operation of the National Operational Meteorological Satellite System (NOMSS). In addition, the Center coordinates all satellite activities within ESSA and maintains liaison with other Government agencies having requirements for satellite data. In operating NOMSS, NESC performs the following functions: Commands and controls satellites in orbit, acquires and processes data from satellites, arranges for dissemination of both processed and unprocessed data, and works with the Environmental Data Service (EDS) to maintain an archival system for making data available for research. The Office of Systems Engineer- ing maintains and improves current ground and data han- dling systems, plans for future spacecraft systems, and co- ordinates with the National Aeronautics and Space Admin- istration (NASA) in the development of new and improved sensor and spacecraft systems. Systems Engineering also works with NASA on the procurement of spacecraft, launch vehicles, and launch services. The NESC also conducts re- search and development (R&D) in two areas: (1) the analysis and application of satellite data, and (2) the de- velopment of sensor systems for use on or with spacecraft. The ultimate goal of ESSA in the Environmental Satellite Services is to furnish observations of the earth and its sur- rounding environment, consistent with the specific agency service responsibilities of ESSA, and to meet requirements of other Government agencies. Partial observations of the earth's surface, its oceans, and its atmosphere, and some observations of the flux of solar protons and X-rays have been obtained by satellite-borne instruments. Spacecraft Systems Two types of spacecraft are to be employed in the total environmental satellite observations system: polar-orbiting spacecraft and geostationary spacecraft. During the period of this report, only one environmental satellite system, the TIROS (Television Infrared Obser- vation Satellite) Operational Satellite (TOS) System, has been in operational use. This TOS System uses Environ- mental Survey Satellite (ESSA) spacecraft in near-polar sun-synchronous orbits to provide global cloud cover pho- tography on the daylight portion of each orbit. The TOS System uses two types of ESSA spacecraft: One type pro- vides global coverage by storing groups of pictures for later transmission to an ESSA Command and Data Acquisition (CDA) Station for central processing; the other takes and immediately transmits pictures to ground stations within range of the spacecraft by means of the Automatic Picture Transmission (APT) System. The APT ground stations are much less complex and less costly than the CDA stations and are owned and operated by U.S. and foreign meteor- ological services, and by individuals. The TOS System is scheduled to be replaced by a second- generation operational system employing a single space- craft, the Improved TIROS Operational Satellite (ITOS). A single ITOS spacecraft combines the functions of the two types of ESSA spacecraft in the TOS System. Each ITOS satellite carries both storage-type and APT cam- eras for daytime viewing and a scanning radiometer system which can acquire data in the infrared range on both the daylight and night portions of the orbit and in the visible range on the day side of the orbit. The ITOS spacecraft also will carry a solar proton monitor whose data will supple- ment other data used in the prediction of geomagnetic storms and of other phenomena that affect high frequency (HF) radio communications. Other sensor systems now under development will be added to the ITOS spacecraft as they are tested and proved operational. The geostationary Applications Technology Satellites (ATS) 1 and 3, launched under a NASA R&D program, carry spin-scan cloud cameras capable of viewing a large disk of the earth at relatively frequent (15- to 30-minute) intervals. These Satellites orbit the earth at an altitude of 22,300 statute miles. With the spacecraft above the Equator, the orbit speed is synchronous with the rotation of the earth, hence the spacecraft appears stationary above a 105 106 NIGHT POSITION IR SCANNING ■~~-- SPACECRAFT IMPROVED TOS EARTH -ORIENTED SENSORS ALWAYS FACE EARTH ORBIT SUN SYNCHRONOUS ALT., 790 N. Ml. 12.5 ORBITS/DAY 114.5 MIN./ORBIT ITOS SYSTEM 4 N 1 ,..^«^-^ %'^^^ \ jS ^^^^^^ SENSORS ^^^^^■^ ^^^^■■l 2 AVCS - STORED PICTURES ^^^^■ni 2 APT -DIRECT READOUT ^^^^^^^^^^M MM SCANNING RADIOMETER: 4''liJil^^^^^^^Bl^H DAY-ALBEDO if^^H^^^^^^^^HP^V NIGHT-INFRARED ^ -MI^^^^^^H^V ^(^LAR PROTON MONITOR: Ipil^^^^^^^Hn^V SOLAR DAY POSITION^ 1 ^^=--'''^ APT & AVCS Pertinent statistics on the Improved TIROS Operational Satellite (ITOS) System. point on the Equator. A number of successful experiments, including real-time operational application, have been con- ducted with the camera data from these Satellites. Results of the experiments clearly demonstrate the utility of a geostationary environmental observatory. Authority has been granted to proceed with the develop- ment of the Geostationary Operational Environmental Satel- lite (GOES) System which will permit nearly continuous monitoring of environmental conditions within view of the spacecraft. The launch of a NASA-developed GOES proto- type, the Synchronous Meteorological Satellite (SMS), is planned for mid-1972. Data Processing and Dissemination The NESC maintains a data processing and analysis capa- bility within its Data Processing and Analysis Division to process satellite data in real-time for daily operational use. For several years, satellite cloud pictures have been proc- essed routinely by computer for operational use. The pic- ture signals are digitized, rectified, and combined into mo- saics for regular transmission by facsimile to U.S. weather stations. The mosaics are also transmitted experimentally, but rather routinely, to Europe, Asia, Australia, Oceania, and North and South America by means of transmitters on ATS-1 and ATS-3. During the past year, additional computerized products have been developed. These include averaged brightness charts which represent the average cloudiness over an area for the time period involved. Five-, 10-, 30-, and 90-day (seasonal) averages have been produced; hopefully these will become the basis for up-to-date global cloud climatology charts. Charts of minimum brightness for 5-day periods show the extent of snow and ice fields, except in those areas where clouds have persisted for the entire period. Bright- ness charts comparing successive 5-day periods show areas nearly covered by snow or areas of recent snowmelt. The APT pictures received at the Wallops Island, Va., CDA Station and at the San Francisco, Calif., Weather Bureau Forecast Office (WBFO) have computer-generated grids added to the pictures that are sent out to Weather Bureau Offices (WBO) on the Forecast Office Facsimile (FOFAX) weather network. This procedure saves manual gridding of the pictures at FOFAX-receiving stations within the conterminous United States. The data processed for operational use are later deposited in archives from which they can be retrieved easily for research use. Data catalogs in the Key to Meteorological Records Documentation (KMRD) series are prepared on satellite cloud photography. As infrared data become avail- able operationally, they too will be cataloged and made available through the National Weather Records Center (NWRC) maintained by ESS A at AsheviUe, N.C. Operational Applications of Satellite Data The operational satellite system has furnished cloud data routinely and reliably since February 1966. Daily oper- ational usage of satellite data is widespread both in the United States and abroad. Digitized mosaics and hand-pre- I 107 Digitized mosaic map of cloud cover in the Northern Hemisphere produced from ESSA 9 spacecraft pho- tographs for August 21, 1969. pared nephanalyses of worldwide cloud conditions are pro- duced centrally in the United States and transmitted to many locations around the world. Meteorologists found the satellite photographs particu- larly useful for discovering the tracking weather systems over approximately 80 percent of the earth where ground- based observations are not available. The discovery and tracking of hurricanes and typhoons from their inception to final breakup are the most spectacular use of this capa- bility. During the past 2 years, more than 100 tropical cyclones, including Atlantic hurricanes, eastern North Pa- cific tropical storms or hurricanes, western North Pacific typhoons, and tropical cyclones of the Indian Ocean were spotted and tracked with satellite pictures. A technique de- veloped by NESC provided the means for making relatively accurate estimates of the maximum wind speeds within a storm by direct examination of the satellite picture. Ad- visories on these storms were sent to U.S. installations and 108 Digitized 3U-day average brightness mosaic map of the Northern Hemisphere produced from ESSA 9 spacecraft daily mosaics for July 13 — August 11, 1969, to determine monthly average cloud cover. foreign meteorological services worldwide. Storm tracking in the middle and high latitudes is used to provide im- proved advisory service, particularly to coastal areas, to aviation, and to ocean shipping interests. Cloud-picture mosaics, prepared from either stored pic- tures or APT pictures or APT pictures received locally, were also used to decrease the use of aircraft for tropical storm reconnaissance, to reduce the time and cost for ac- complishing photomapping of remote areas, and to eliminate the need for keeping a costly weather-observing ship on sta- tion between New Zealand and Antarctica. Picture mosaics were also used to produce weekly maps of ice conditions in the Great Lakes, the inland waterways, and coastal areas of North America, the Arctic, and the Antarctic. These maps are used by shipping interests in these areas and are particularly useful for routing ships on Antarctic resupply missions. Witids at the 30,000- to 40,000-foot level, estimated from ESSA photographs, are used routinely in computer analyses and are transmitted daily to users worldwide. These esti- mates provide wind information over tropical and sub- tropical areas that are almost completely devoid of conven- tional upper level wind information. Research and Development Programs The research programs of the NESC include two gen- eral program elements: Studies designed to extract the maximum possible amount of useful information from satel- lite observations, and studies designed to determine the kinds of observations possible from satellites. In the first program, studies lead to an increased understanding of at- mospheric processes, and to the development of methods for using satellite data in daily operations to improve analy- ses and forecasting of weather and other environmental features. The second program of study leads to the con- ceptualization and development of new instrumentation for measuring environmental data from a satellite platform. Applications of Satellite Data to Environmental Analysis and Prediction In this general program, research is directed toward devising methods for abstracting as much information as possible from satellite data, and toward developing methods for using these data in meteorological, hydrological, and oceanographic analysis. Because the data have been pre- dominantly meteorological, emphasis thus far has been on atmospheric applications. The picture data have been used to determine atmospheric conditions, synoptic patterns, and snow and ice conditions and to follow the movement of storm systems and weather patterns. The pictures also are used as a basis for esti- mating quantitatively the winds near the earth's surface and high in the atmosphere. Cloud pictures also are being used in the development of an objective method for deriv- ing constant pressure heights for use with numerical analysis and prediction models of the atmosphere. Picture data are used to study the development of both midlatitude severe storms and tropical cyclones and weather patterns. Mesoscale patterns of cumulus activity and cloud patterns influenced by the presence of mountains are also under study. Radiation data are used in studies of the dynamics and energy patterns of general atmospheric circulation for the depiction of ground and sea-surface temperature distribu- tion, cloud top topography, and ocean current location. Near the end of FY 69, the availability of Satellite Infrared Spectrometer (SIRS) data led to intensive and successful work on the development of methods to relate those data to atmospheric temperature profiles. Methods were also de- veloped to use the SIRS data to construct constant-pres- sure surface contours and to integrate the data into nu- merical analysis programs. The near-continuous observational capability of the spin- scan cloud cameras of the ATS spacecraft has been used in a number of operational experiments. Procedures for .^ Ml fW^ r^TT^PT'^P *'^^...: 0p^ W^'*' 1758 CST Growth of severe thunderstorms in a Midwest tornado situation as shown in photographs taken from the synchro- nous ATS-3 spacecraft on April 19, 1968. making time-lapse motion picture film from ATS-1 and ATS-3 photographs have been greatly refined in the past 2 years. It is now possible to study the conditions in a hurricane within 1 or 2 hours after the pictures are taken, and to use the information for making forecast decisions on the motion and intensity of the storm. Pictures taken at 15-minute intervals by ATS-3 were used in 1969 for the first time in a real-time operational experiment for fore- casting the movement of a hurricane. At first, the storm appeared to threaten the gulf coast, but daily examinations of the pictures contributed toward an early and definite forecast of an "all clear" for the coastal area. A substan- tial saving probably resulted because it was not necessary to issue warnings to evacuate coastal areas and to protect property from hurricane winds and tides. The ATS picture films are also used daily to estimate high- and middle-level winds over the entire Pacific Basin. The wind estimates are used as data input to the objective analysis programs proc- essed by high-speed computers. Data from the still active ATS-1 and ATS-3 spacecraft are being used for operational experiments in storm tracking and forecasting. Experimental forecasting of east coast snowstorms, using ATS-3 pictures as a unique data source, is planned for the late winter season of FY 70, and will continue during the winter season of FY 71. The ATS pictures will also be used experimentally during the 1970 tornado and hurricane seasons by the Severe Local Storms i ., 110 Digitized 5-day average minimum brightness mosaic map of Alaska, Canada, and Greenland produced from ESS A 9 spacecraft daily mosaics for June 11 — 15, 1969, to show the extent of snow cover. (SELS) Unit of the National Severe Storms Forecast Cen- ter (NSSFC) at Kansas City, Mo., and by the National Hurricane Center (NHC) at Miami, Fla. These Centers will receive ATS-3 pictures by means of a real-time photo- facsimile relay from the NESC's CDA Wallops Island, Va., Station. In hydrology, techniques were developed that permitted the use of satellite pictures for mapping snow cover and ice fields in lakes, rivers, and the open ocean. Prior research has established that the edges of snow fields can be located with a reasonable degree of accuracy. Current research is directed toward finding ways to determine the depth of snow cover and toward improving location accuracy. Estimates of snow cover, based on computer-processed satellite pic- ture data, assisted hydrologists in making accurate fore- casts of the flooding potential over the North Central and Rocky Mountain States in the spring of 1969. Radiation data were available from the Nimbus 3 satel- lite from two sets of instruments. The 5-channel Medium Resolution Infrared Radiometer (MRIR) and the single- channel High Resolution Infrared Radiometer (HRIR) pro- vide information by scanning across the path of the satel- lite as the satellite moves in orbit; SIRS provides informa- tion by sensing radiant flux originating at various levels in the atmosphere. The MRIR data, with a resolution of about 30 nautical miles, provide information for mapping the horizontal dis- tribution of moisture at upper levels and, at lower levels, the albedo (reflected sunlight), stratospheric temperature, and cloud top and surface temperatures. The HRIR instru- ment senses surface and cloud top temperatures at a much finer resolution (about 5 nautical miles) than does the MRIR instrument. The radiant flux from various levels in the atmosphere is sensed by the SIRS. This instrument, which had been under development for 10 years, performed spectacularly well; it provided temperature soundings within hours after the April 14, 1969, launch of Nimbus 3. The SIRS instrument measures infrared radiation from various levels in the at- mosphere. These measurements are converted by mathe- matical processing to vertical temperature profiles (sound- ings) of the atmosphere. Seven measurement channels pro- vide data for the sounding; the eighth channel provides measurements of the temperature of cloud tops or, in cloud- free areas, the temperature at the surface of the earth. Since the first SIRS measurements were obtained, a steady stream of measurements, equivalent to some 8,000 to 10,000 atmospheric soundings over the globe, have been received every 24 hours. For practical considerations, only 400 soundings are computed daily for operational use in the Northern Hemisphere numerical weather analysis; addi- tional soundings over the Southern Hemisphere are com- puted for later use in research programs. The Northern Hemisphere soundings derived from SIRS radiance meas- urements have been used in daily operations since June 1969 in the Weather Bureau's (WB) numerical upper air analyses for 1200 GMT (Greenwich Mean Time). Experi- mental comparison forecasts, starting with 500-millibar analyses without and with SIRS data, have shown that the addition of SIRS data has, at least in the cases studied, Ill -PRIMARY MIRROR EARTH BEAM OPERATIONAL AMPLIFIERS - BEAM BLOCKER ORDER FILTER-ENTRANCE SLIT - BLACKBODY -EARTH MIRROR TWO POSITION (BLACKBODY) SPACE BEAM PHASE REFERENCE ASSEMBLY The SIRS instrument designed to measure the vertical temperature profile of the earth's atmosphere from satellite altitudes. Forecast 500-millibar patterns for June 25 (12 GMT), with and without the use of SIRS data, compared with the observed pattern. 112 I I 1 40 60 RMS DIFFERENCE (MEIERS) Root mean square error and diflference com- parisons of SIRS- and radiosonde-derived geo- potential heights. resulted in significant improvement in forecasting some major features of the midtropospheric flow. Oceanographic research using satellite picture data and infrared data separately or in combination was started in 1968. The specular reflection patterns of the sun on the ocean surface are being analyzed as a means for determin- ing surface wind speeds in remote areas. Basic methods have been developed for this determination; current work is directed toward the development of a computer program that will accomplish the necessary analysis in a time suffi- ciently short for operational use. Infrared data are used to map ocean-surface temperature fields and surface currents, such as the Gulf Stream, and to determine moisture pat- terns in the sea-air interaction layers of the atmosphere. Investigations are directed toward determining the pos- sibility of using microwave sensors to provide some of the above data and to provide measurements on the tem- perature structure in the upper levels of the ocean. The in- formation is expected to be useful both for oceanographic and meteorological purposes. Design and Development of Satellite Sensors and Systems The R&D under this general program in NESC is di- vided into three basic program elements: the design and development of specific instruments, the design and study of instrument components and materials, and the study and development of both concepts and techniques for observing various environmental parameters from satellites. Instruments developed under the first program mentioned above include the very successful SIRS described earlier. The SIRS remote sensing technique for obtaining measure- ments of the vertical temperature profiles of the atmos- phere is considered one of the major technical breakthroughs of the decade. An improved version of SIRS, designed to measure moisture and temperature, is being readied for flight on Nimbus D in 1970. Another instrument derived from the SIRS concept is being developed for flight testing on Nimbus E. This is the Infrared Temperature Profile Radiometer (ITPR), which will have spatial scan capa- bility to improve operations over areas partly obscured by clouds. A spectrograph instrument to determine the height of cloud tops by measuring the absorption of reflected light in the oxygen "A" band continues under development. This spectrograph has been tested during aircraft flights, and the data show positive correlations between the measured absorption and the cloud top heights. Materials and instrument components are studied and tested in support of the second continuing program to im- prove existing instruments and to develop new sensors. For example, diffuse reflector materials for on-board calibration of the visible channel of satellite radiometers are being identified, and a low temperature black-body radiator for use as an in-flight calibration standard is being studied. Detailed studies are being conducted on the effects of the chemical and physical characteristics on the sensing of environment parameters from a space platform. These effect factors also affect the development of techniques to convert the sensed data to representative quantitative values. This third program includes studies on the optical proper- ties of clouds and on the effect of atmospheric turbidity upon satellite sounding. New techniques for obtaining observations are under in- vestigation, for example the use of light detecting and rang- ing (Lidar) equipment to detect the type and amount of atmospheric aerosols present at a given time and to obtain measurements of the diffraction characteristics of clouds. Also under study is the use of microwave sensors to ob- tain measurements of surface temperatures through cloud decks, and of sea-surface conditions (sea state) in the ab- sence of specular reflection patterns. Microwave sensing is also being studied for its possible use in obtaining at- mospheric sounding data. A satellite-interrogated buoy system was under develop- ment during the last 2 years. The system concept is to use instrumented buoys moored at deepwater stations. The data acquired by the instruments are to be transmitted to a satellite upon interrogation, and then relayed to an analysis center. The buoy was designed and two prototypes tested on location in the North Atlantic Ocean. Both tests suc- cessfully demonstrated the stability of the buoy and the durability of the mooring system. The Coast Guard assisted in mooring the buoy and maintained visual and radio checks on the buoy during each test period. 9 ENVIRONMENTAL DATA AND INFORMATION Service Programs ESSA has a major responsibility for both research and dissemination of environmental data and information. The Environmental Data Service (EDS), a Major Line Com- ponent (MLC) of ESSA headquartered in Silver Spring, Md., maintains specialized data centers for meteorological, geodetic, seismological, geomagnetic, oceanographic, ion- ospheric, space disturbance, and other geophysical infor- mation. The Scientific Information and Documentation Divi- sion (SIDD), located at ESSA Headquarters in Rockville, Md., provides an informational retrieval and storage center for all research and development (R&D) projects underway in ESSA. During the reporting period, both organizations initiated R&D activities to improve their respective data centers. Environmental Data Service The EDS component of ESSA is responsible for the col- lection, quality control, storage, retrieval, display, and dis- semination of worldwide geophysical data relating to the atmosphere, oceans, solid earth, and space. These data come from the MLCs of ESSA, other governmental agencies, and cooperating nations. Climatological Data Service EDS's Climatological Data Service programs include the collection, processing, analysis, interpretation, and dissemi- nation of information concerning various climatic elements. Through increased understanding of climate and its effects upon aviation, agriculture, construction, transportation, commerce, health, and recreation, users of climatological data are able to make more effective decisions in their responsible field. Climatological data are collected at EDS from four pri- mary sources. The first source is the hourly reports of sur- face weather conditions received on a regular 24-hour basis from approximately 610 stations — 310 from the Weather Bureau (WB) and 300 from the Federal Aviation Adminis- tration (FAA) — in a joint WB-FAA station network, plus U.S. military stations throughout the world. A second source is the data obtained from the WB's 205 upper air stations (134 furnish temperature, pressure, and humidity data; all furnish wind data). A third source is the data provided by about 12,000 volunteer precipitation-observing stations, of which approximately 5,000 forward daily temperature readings. Supplementary data are also collected from about 1,000 special-purpose agricultural and public service sta- tions. The fourth source is data reported by the Reference Climatological Stations; about 17 of these Stations have been i>ermanently located in environmentally stable regions with long histories of homogeneous observations and good prospects for future continuity. Volunteer Observing Network Daily readings of maximum and minimum temperature and precipitation are a minimum requirement to define the climate of a region. Such volunteer readings are obtained at present from a network of reporting stations, spaced approximately 25 miles apart, in selected locations through- out the Nation. Currently, about 5,000 cooperative sta- tions constitute the basic climatological network. The re- ports of all 13,000 cooperative stations are sent by mail monthly to the National Weather Records Center (NWRC) at Asheville, N.C. State Climatology The EDS provides a special service geared to the cli- matological conditions of the individual State or region. The key individual is the State or Regional Climatologist who is an expert on the climate within his State or region of responsibility. His key task is to work with local and State organizations, frequently through the State univer- sities or colleges, and to assist these organizations in the solutions to problems which have an impact on the State or local economy. As part of the State Climatologist's 113 114 service, he answers requests for climatological data. For example, he provides climatological data to engineers who need such data for use in the design and layout of buildings or to agricultural county agents who require growing con- dition data and other related information. Forty-four State Climatologists and six Regional Climatologists serve the 50 States and Puerto Rico. National Weather Records Center Among the functions performed by the N'WRC are the routine collection, quality control, punching, verification, processing, analysis, publication, and final storage of U.S. climatic records. In addition, the Center prepares special nonroutine studies like the periodic summarization of cli- mate and makes special studies for public and private agen- cies. The NWRC houses World Data Center A (WDC-A) for meteorology and nuclear radiation, under sponsorship of the National Academy of Sciences (NAS). The Center contributes to international climatological efforts by pro- viding representation to working groups of various tech- nical commissions, such as those engaged in maritime me- teorology and climatology. Operator handling microfilm spool of weather records within the "clean room" of the NWRC, Asheville, N.C. Central Data Dissemination For the benefit of public and scientific users, climatologi- cal information is available from EDS's Office of Data In- formation in Silver Spring, and from NWRC in Asheville. Dissemination of information occurs as maps, tabular rec- ord summaries, regular publications, letter supplements, and brochures. Geophysical Data Centers An important part of the data systems activity includes the Geophysical Data Centers — consisting of the Seismo- logical Data Branch and Geodetic Data Branch of the Na- tional Geophysical Data Center in Asheville and the Geo- magnetic Data Center in Rockville. The Geodetic Data Branch collects, prints, archives, and disseminates final data pertaining to all geodetic station data processed by ESSA. Data for horizontal control sta- tions consist of verbal descriptions of the station locations, azimuths, geographical positions, and plane coordinate positions. Data for vertical control stations include verbal descriptions of the central locations and station elevations. Index maps of control station locations are also available. As of the end of FY 69, approximately 185,000 geographic control positions (horizontal control stations) and 320,000 elevations (vertical control stations) were on file in the Geodetic Data Branch. The Seismological Data Branch collects, films, archives, and disseminates final data from an international network of seismograph stations. Most data disseminated by this Branch consist of standardized seismogram copies. These seismograms are distributed to seismologists, other scien- tists, and engineers throughout the world. These data are invaluable research tools for determining estimates of earth- quake magnitude, for improving accuracy of earthquake predictions, and for increasing knowledge of the earth's physical properties. As of the beginning of FY 70, approxi- mately 1.5 million seismograms were on file in the Seismo- logical Data Branch. The Geomagnetic Data Center is one of four worldwide Data Centers for Geomagnetism (the other three are in Denmark, Japan, and the Soviet Union). Microfilm copies of daily magnetograms and processed data from approxi- mately 185 world observatories are transmitted to one of these four Centers for archiving and for disseminating upon request. Through a mutual exchange program, each Data Center receives input for its data bank from the other three. Inputs from 15 ESSA observatories and approximately 50 observatories of other countries are sent initially to the Rockville Center. As of June 30, 1969, approximately 850,- 000 magnetograms were on file in the Geomagnetic Data Center. OCEANOGRAPHIC DaTA CeNTER Oceanographic data — exclusive of geophysical, mapping, tidal, and tidal current data — are available to users through the National Oceanographic Data Center (NODC) in Wash- 115 Researching triangulation points on the North Carolina Triangulation Diagram at the Geophysical Data Branch of the National Geophysical Data Center, Asheville, N.C. ington, D.C. This Center, the largest repository of ocean- ographic data in the world, was established in 1960 through the cooperative effort of various governmental agencies par- ticipating in the National Oceanographic Program to serve as a centralized oceanographic data bank. The Center is administered by the U.S. Naval Oceanographic Office. Ten agencies and bureaus — including ESSA — ^fund NODC, with the level of support from each based on data input. Policy and technical review functions are exercised by the 12- member NODC Advisory Board, composed of representa- tives from each supporting agency and bureau and two re- search community representatives appointed by the NAS. Data collected and analyzed from participating agencies and bureaus are assembled and stored at NODC for dissemina- tion upon request. Upper Atmosphere and Space Environment Data Center Another of the data systems available to users is the Aeronomy and Space Data Center, funded by the EDS to collect upper atmosphere and space environment data essen- tial for space environment and telecommunication predic- tions and to satisfy scientific research needs. On a regular and continuous schedule, this Center, located at the Re- search Laboratories (RL) Headquarters in Boulder, Colo., receives, exchanges, compiles, stores, and publishes final data to aid the geophysical disciplines. The great majority of the upper atmosphere and space environment data are collected through continuing national and international agreements established during the 1957- 58 International Geophysical Year (IGY). The Aeronomy 116 and Space Data Center manages and operates WDC-A for those scientific subjects. Data are exchanged regularly with World Data Center B (WDC-B) in the Soviet Union and with World Data Center C (WDC-C). Because WDC-C is comprised of four European countries — France, Italy, Swe- den, and the United Kingdom — and Japan, exchanges are effected only with the country that has responsibility for a specific scientific subject. Data relating to the ionosphere, airglow, aurora, cosmic rays, solar activity, and aeronomy, received from observatories throughout the world and from upper atmosphere monitoring satellites, are involved in the exchanges. Science Information Science information activities include the collecting, proc- essing, compiling, analyzing, indexing, storing, retrieving, publishing, and disseminating of scientific and technical in- formation. Such activities involve most of the substantive work of the MLCs of ESSA — ^from the initial observations of land, sea, or atmospheric elements to the resultant fore- casts or warnings based on the observations and on the understanding gained through research or theoretical studies. All of these activities are covered in other chapters of this report. In this chapter, the narrower definition of sci- ence information implies collection, storage, and retrieval of published documents or their surrogates — such as ab- stracts, summaries, announcements, indexes, catalog cards, microforms, punched cards, and tapes. The SIDD of the Office of Administration and Technical Services, ESSA, is charged with developing, maintaining, and performing the above systems or services, including libraries and publications, necessary to provide environ- mental scientific information developed in ESSA or else- where in the world to users in ESSA and other Govern- ment agencies or to the general public. Research and Development Programs The EDS conducts in-house studies and supports some R&D projects at selected universities and consultant firms. These various studies and projects deal first with the ident- tification and development of data retrieval and storage systems, and with the equipment needed for more rapid and efficient automatic processing and dissemination of present and future environmental data; in addition, in- vestigations into applications of the data help develop meth- ods of analysis which dictate how data shall be archived. Special studies are conducted in support of the climato- logical services program of EDS, including the development of design data for use by various industrial users; analysis of records to facilitate the production of food more effi- ciently, to permit the design and operation of better engi- neering structures and processes, to aid in the preparation of better weather forecasts, and to determine the causes and processes of climatic change are also made. Many tech- niques are applicable to other data systems programs oper- ated by ESSA. Gridding Northern Hemisphere map data with a Large-Area Record Reader (LARR-V) at the NWRC, Asheville, N.C. 117 Data Systems Development The NWRC processes a rapidly growing volume of weather observational data. Approximately 100 million U.S. and foreign meteorological observations are received an- nually, including climate, marine, upper air, synoptic, sur- face, and aviation observations. Work is in progress to design and construct equipment to transform these ob- servational data into compact, pertinent formats to achieve rapid retrieval and maximum usage of data. A preliminary 10-year plan for archiving climatological data has been prepared; as needs of other geophysical dis- ciplines are determined, these disciplines will be integrated with climatology into an efficient, total geophysical data sys- tem. User needs will be subject to study to determine their data requirements and to encourage further exploitation of the records by all disciplines. A fast, cheap means of achiev- ing automation, miniaturization, random access, and repro- duction will occur gradually rather than as a single break- through. The development of a Film-Optical Sensing Device (FOSDIC) was undertaken by the EDS Systems Design Group during the reporting period as a cooperative project with the National Bureau of Standards (NBS). This proj- ect involved the production of a third-generation electronic system for high-speed reading, editing, and conversion of microfilmed punched card data to digital magnetic tape. A small, commercially available, general-purpose computer and appropriate off-the-shelf peripheral equipment were used to design and construct a more reliable, easier-to-use sys- tem. The basic system was designed, and the film scan director and film handling units were constructed. During the past 2 years, a new, improved electronic reader, incorporating off-the-shelf computer and tape-writing means, was under development. A high-resolution plane- tary camera with automatic feed was designed, built, and tested to determine further ways to improve low-cost, high- quality reduction of paper records to microfilm. Another EDS study in data retrieval and storage sys- tems involves environmental data formats. The objectives of this study at the University of Wyoming are to classify and interrelate the various kinds of environmental data, to fit the classification into an environmental data index, to postulate the optimum format and content for various kinds of environmental data, and to recommend the equipment and procedures required to implement an adequate Environ- mental Data Service. An analytical study of these geo- spheric operations from which environmental data are acquired has been undertaken. Investigators observed oper- ations in EDS and other data banks. Definitions of the ele- ments of the environmental data index were developed and methods for analysis of geospheric operations were de- scribed. A preliminary report on pictographic numerals for space-time coordinates has also been completed. Synoptic Climatology A major research effort in synoptic climatology by EDS's Laboratory for Environmental Data Research (LEDR) in- volved the development of computer methods to analyze Alaskan weather records from January 1945 through March 1963. Synoptic weather patterns from these records were identified and classified as a means to establish proba- bilities of weather systems occurrence in the Arctic. The monthly and annual variations of zonal and meridional in- dices, based on the heights and thicknesses at certain milli- bar levels, and temperature gradients (zonal and merid- ional) were investigated over Alaska. The predominance of the semiannual variations over certain sections of Alaska has been associated with general patterns of circulation over the northern part of the Pacific Ocean and with frequencies of low and high centers over Alaska (at the 700-millibar level) . As part of this research effort, several problems were under investigation, including the height and strength of the surface inversion; mean and variation of monthly 500- millibar height and 500/1,000-millibar thickness; height, pressure, and temperature at the tropopause over Alaska; and interdiurnal changes of these parameters. Additional facets of this project treated the Alaskan anticyclone, its influence on the surface conditions, and the influence of sur- face conditions upon the anticyclone, and investigated the preferred sites of cyclogenesis in the vicinity of Alaska and the reason for such development. Investigations by LEDR into climatic conditions in Alaska focused on the mean weather conditions during occurrences of specific weather patterns over the State; namely, those patterns derived from the records for January 1, 1945, to March 31, 1963. Correlations were found between the changes of 500-millibar heights and 500/1,000-millibar thicknesses from month-to-month, and between mean month- ly temperature gradients at 700-, 500-, 300-, and 100-milli- bar levels in meridional and zonal directions over Alaska. These correlations were evaluated and harmonic analysis methods were applied to annual variations of: (1) thick- nesses at the 500- to 700-millibar, 300- to 500-millibar, and 100- to 300-millibar levels; (2) gradients of thicknesses in meridional and zonal directions; and (3) isobaric tem- perature gradients at the 700-, 500-, 300-, and 100-millibar levels. Developing weather systems were studied to achieve pos- sible feedback into weather forecasting techniques. These studies have expanded knowledge of expected operating conditions in Alaska for military personnel and equipment and for natural resources development of the State. As a basis for planning structures, transportation, and popula- tion support, a knowledge of weather patterns promises help. Climatic Change Supporting research in climatic change is aimed at a broad investigation into the overall problem of climatic change in the 20th century to meet long-range national planning goals. This research is concerned with: (1) diffi- culties of reliable measurement of climatic change; (2) sta- tistical character and meteorological interpretation of cli- matic change; (3) causes of climatic change including 118 those related to man's activities; (4) predictability of fu- ture climate; and (5) impact of climatic change on man and environment. The approach has consisted basically of three elements. The first element is the analysis of extant historical climatic data to verify past climatic change and the establishment of new observational programs (notably the Reference Climatological Station Network Program) to document future change more adequately. The second in- volves study of the statistical nature and physical inter- pretation of climatic change through techniques of time- series analysis to determine the form of nonrandomness in climatic variability, gaining clues to its physical causes and predictability. The third element includes application of physical climatology theory and numerical modeling experi- ments of atmospheric circulation and climate to obtain a basic understanding of the physical mechanism, cause, and predictability of climatic variation. Progress in research on climatic change is closely related to progress in knowledge of the general atmospheric circu- lation, to advances in numerical simulation and prediction of the atmosphere, and to improvements in the worldwide observational network for reporting meteorological and oceanographic conditions. Research gives new insights into meteorological consequences of such environmental dis- turbances as solar activity, lunar and solar tides, volcanic activity, sea-air interaction, and atmospheric pollution. Climatic change research by LEDR focused on five distinct study areas. The first study area is expansion of the Reference Climatological Station Network to 17 stations, complete with new instrumentation for the measurement of resultant wind, and continued development of additional instrumentation to be made in the Network at a later time. The second area includes reprogramming the temperature homogeneity analysis used to verify the quality of historical climatic records, and extending this analysis to maximum and minimum temperatures separately on a pilot study basis in Maryland. The third involves preliminary updating of a worldwide index of long-term temperature change, initially calculated to 1960, which indicated a continued cooling of world climate during the past decade. The fourth centers on an evaluation of the role of global air pollution — carbon dioxide and atmospheric dust loading — in causing world- wide fluctuation of temperatures during the past century and in contributing to temperature trends anticipated for future decades of this century. The fifth and final study area comprises a continued study of climatic change in the geological and historical past, together with the various environmental disturbances in the past that may have caused such climatic change, to gain the necessary perspec- tive on environmental forces that contribute to climatic changes at the present time. From the latter two study areas, it is becoming increasingly clear that the fluctuation of worldwide climate in the last century resulted primarily from natural causes of still unknown specific character. Human activities are capable, however, of causing global climatic change, and threaten to become a dominant cause of further climatic change in the future if industry and technology advance as anticipated. An ancillary LEDR study at the University of Arizona's Laboratory of Tree-Ring Research concerns the application of historical tree-ring data in developing a detailed chronol- ogy of climatic conditions throughout the western portion of the North American continent during the past 500 years. The research approach required calibration of modern tree- ring series against concurrent meteorological data through an elaborate statistical analysis to isolate climatic factors, to obtain anomalous ring thicknesses for each tree species and for each physiographic setting, and to use this calibra- tion to infer past climatic conditions from earlier tree-ring chronologies. Research in the past 2 years has progressed to the stage where this method of indirect climatic reconstruction has produced highly realistic patterns of climate and atmos- pheric circulation over the western portion of the United States. The resultant patterns indicate periods of severe drought in the Southwest that correlate with archaeological evidence of agricultural and social upheavals in that region during those times. The main objective of this research is to supplement the relatively short meteorological history of the Nation by establishing the statistical probability of recurrences of persistent droughts and other extreme climatic anomalies of the kind that have occurred in recent decades. A statistical analysis was made of historical tree-ring data and solar activity indices to determine the extent of a relationship between climate and long-term solar variability. A principal component analysis of ring variations at 26 dif- ferent tree sites in western portions of North America and a cross-spectrum analysis between these components and sunspot numbers revealed only weak evidence for any such relationship. It is expected that this particular research investigation will provide a better indication of the risk of extreme climatic anomalies in the future and will help detect causal factors in climatic change such as historical variations in solar activity, BlOCLIMATOLOGY One of the more important programs of EDS is bio- climatological research which has application in agriculture, health, and recreation. During the past 2 years, EDS, through its LEDR, conducted research to develop an under- standing and quantitative characterization of those climatic aspects which impose limitations on the success and effi- ciency of agricultural program planning, food production, and water resources management. Much of this diversified program is conducted through contract-supported research at a number of universities; the aim is to create a better understanding of the basic relationships of evaporation, transpiration, wind shelter effects, precipitation, energy bal- ance at the earth's surface, and corresponding responses in plants and animals. The internal EDS effort concentrates on methods for using this acquired knowledge to facilitate a uniform food supply, with minimum stress on the Nation's resources and at minimum eventual cost to the consumer. A computer procedure was adapted to determine the 119 extent, severity, and duration of periods of unusually wet or dry weather. This procedure was applied to the historical record of weather and climate since 1930; drought severity has been calculated on a monthly basis for all areas of the United States and Puerto Rico. An additional procedure was developed using weekly temperature and precipitation observations to compute consistent week-to-week appraisals of crop moisture conditions throughout the United States and Puerto Rico. These results are published for the use of Government agencies and other groups having an interest in agriculture and business generally. A consulting office — ^Agricultural Climatology Service Office (ACSO) — was established within the Department of Agriculture (DOA) to interpret meteorological information for agriculture problems. The ACSO can and does assist farmers with timely information. For instance, the annual influx of the screwworm into the Southwest is influenced by how far south into Mexico this agricultural pest was pushed by freezing winter temperatures and by how much summer moisture is available for its survival and spread. The sterile fly control program can be managed better if knowledge of temperature and soil moisture from winter through summer is available. Constant climatic surveillance along the United States-Mexican border ultimately will be a decisive factor in the eradication of this destructive ani- mal parasite from all of North America. This liaison office — ^ACSO — in the DOA was established to bring environmental data directly to the problem. Because applied climatology is necessarily interdisciplinary, the climatologist can use his data and methods of application in cooperation with engineers, pathologists, entomologists, or agronomists. This principle of interdisciplinary cooperation has proven practical; it will be employed in other EDS areas of application as resources and opportunities permit. The EDS research in bioclimatology extends to work be- ing accomplished in hydrology, agricultural meteorology, and extended forecasting in the WB. Further, the efforts of EDS contribute to international progress through com- missions and working groups of the World Meteorological Organization (WMO), United Nations Educational, Scien- tific, and Cultural Organization (UNESCO), Food and Agriculture Organization (FAO), and others; these efforts are concerned with widespread drought, methods of assess- ing weather effects on plants and animals, ways of making management decisions in industry and economics, and means of providing pertinent data collection and dissemination. During the past 2 years, EDS has completed a study on the operation of a mesoscale network of integrating pyranometers and made an analysis of radiation data ob- tained from pyranometers in Wisconsin. The study and analysis was conducted by the College of Agriculture at the University of Wisconsin. A known cosine-response dif- fusing head was modified to contain a silicon solar cell and to have adjustable output. From among several integra- tors, a suitable model for reliable all-weather operation was developed. Seventeen pyranometers were field-tested to note and correct deficiencies. The variability of radiation totals obtained is being studied for application to the design of future networks. Daily radiation measurements were started in December 1966, and are being continued through the winter of 1969-70. Except for occasional missing observa- tions, errors of only one Langley per day appear to be most prevalent even during this experimental period of operation. Texas A&M University, through LEDR, initiated a study to determine whether quantum efficiency for photosynthesis in higher plants is sufficiently constant with wavelength to justify its use as a rational physiological basis for a new system of light measurement; if proven constant, a single representative spectral absorptance curve could then be used to convert from radiant energy flux incident to quantum flux absorbed. This study involved the growing of a large number of food plants under controlled and natural condi- tions. At suitable intervals during the growth cycle of each plant, leaves were selected to measure the photosynthetic rate and spectral absorptance. To measure photosynthetic rate, the sample leaf was placed in an assimilation chamber and irradiated with monochromatic light; to measure ab- sorptance, the leaf was placed in an integrating sphere and irradiated with the same light. The spectral quantum effi- ciency and the spectral absorptance were calculated from the results of these two sets of measurements. Final results, expected in mid-1970, will guide ESSA in measuring mean- ingful radiation quantities in the future. Purdue University was awarded a LEDR-grant to initiate research on predictions of diurnal and seasonal temperatures at varying depths within soil profiles through a field and laboratory study in Indiana. The research approach in- volved estimating the depth at which the diurnal change (amplitude) in temperature is 12 hours out-of-phase with high noon and the depth at which diurnal variation ap- proaches zero. Estimates of annual and seasonal soil tem- perature trends and lags at the depth where diurnal varia- tion approaches zero were also made. Maintenance and calibration procedures for use of the Palmer Soil Thermom- eter were completed. Several soil temperature observational stations were established, and programming of several data analysis procedures was also accomplished. Results indicate that it may be possible to estimate long-term temperature distributions in time and depth of soil from a very short period of onsite observations, enabling action programs in new areas to progress quickly. Another EDS project involved the collection and analysis of phenological data for the western portion of the United States to determine climatic relations and natural patterns of the environment in that portion of the country. The project was conducted by Montana State University. Plant genotypes were established, and dates of budding and flowering in relation to measured climate in more than 1,000 locations were then recorded. Observations from lilac plant- ings from 1957 through 1969 were computerized for irregu- larities. Mapping the geographical pattern of standard deviation of plant development in the Western United States denoted a maximum of variability in the Southwest. Multiple regression analysis of median flowering dates revealed some wide departures from Hopkins' Bioclimatic Law. The possibility of operating a uniform phenological network throughout most climatic zones of the conterminous 120 United States definitely exists. These observations can be important in interpretation of future earth resources data obtained through remote sensing procedures. Immediate uses include detection of insects and disease spread in terms of seasonal progress. A growing degree-day study was contracted through LEDR to the Ohio Agricultural R&D Center. Research was initiated on the establishment of a standard method for determining "varietal constants" of corn hybrids in Ohio and the development of normal growing degree-day unit values for all areas within that State. This study involves utilization of several methods for determining heat or radia- tion units and then relating these units to "varietal con- stants" for corn. A modeling procedure is being employed to refine the relationship of accumulated heat units during the growing season with phenological events. Prospects for gaining acceptance of a standard growing degree-day system among major hybrid seed corn producers are excellent. The University of Hawaii obtained a grant from the LEDR to conduct research into the energy budget of Hawaii. Measurements of solar radiation, surface albedo, radiation, and other environmental factors were made with Eppley Pyrheliometers, Monteith Solarimeters, a recording silicon photovoltaic solar cell, a Thornwaite Net Radiometer, and other instruments available locally. Influences of such various surfaces as asphalt, latosol, pineapple and sugarcane fields, buffalo grass sod, rain forests, and sand beaches were compared by albedo measurements. Much of the re- search effort was directed toward calibration and com- parison of radiation instruments. Net radiation measure- ments at different elevations along the southern slope of Mauna Loa were also recorded. An empirical formula was derived to express net radiation as a function of incoming radiation, Angot's value, temperature, and humidity. Re- search was completed in FY 69. As part of its program in biocHmatology, EDS conducted a study to measure evapotranspiration from a high produc- tion field crop in Missouri and to relate these measurements to environmental data. The University of Missouri fulfilled the research requirements for the study. A simple lysitneter and energy balance techniques were used to obtain estimates of total evapotranspiration in irrigated crops for period of several days. Good estimates of evapotranspiration were obtained over long time periods. A precision lysimeter has been installed to permit further evaluation of more specific causal factors in terms of daily water losses. An EDS study to determine a reliable estimate of actual daily evaporation as a function of measurable soil waterflow characteristics, of a plant canopy characteristic, and of potential evapotranspiration was performed by the Univer- sity of Wisconsin. Both the amount of water in the root zone and the rate of waterflow to the root system in a drying soil were deemed important to the estimate; the surface soil temperature and the nature of the plant canopy as a diffuse vapor source were also considered in estimating actual evapotranspiration in a given weather situation. Initial in- strumentation was started. Research for LEDR by the University of Nebraska, in- volving measurements of evapotranspiration and photo- synthesis over short time periods to determine the simulta- neous interactions of these two phenomena, was underway during the reporting period. Climatic and plant responses were recorded with a lysimeter and other meteorological in- struments in a site with optimum fetch of airflow over the instrument location. Aerodynamic and energy balance esti- mates of evapotranspiration rates were compared. The in- struments and recording equipment at the alfalfa crop site were placed and made operational. Analysis of data is in progress. Mesoclimatology The EDS research in mesoclimatology is concerned with investigations on how man is changing his environment in the mesoscale through industrialization, land clearing, air pollution, and urbanization, and on how this knowledge can be applied in the future. Effects of these research investiga- tions are somewhat long range because they point out observational needs and provide avenues of approach to pollution problems. Determining what to measure and how to evaluate fluctuations in this measurement are basic to the conservation and improvement of the environment. During the past 2 years, studies of the influence of soil radiative properties on station temperatures and research into the effects of urbanization on temperature were under- way in LEDR. Temperature-measuring devices, suitable for use in vehicles, were purchased and deployed in Washington to measure air temperatures in that city. Illumination measurements were also analyzed in a restricted portion of the Eastern United States. These illu- mination data and statistics are useful to assess remotely sensed radiometric data from meteorological satellites. Meteorological satellite data were also applied to cloud climatological analysis. Long-period change in cloud cover over the Pacific Ocean was found to be related to change in the general atmospheric circulation and to variation in the temperature distribution of ocean water. Three-Dimensional Global Climatology Research into three-dimensional global climatology was performed at NWRC for LEDR and involved the determina- tion of: (1) static structure of the atmosphere from the surface to as great a height as feasible; (2) dynamic struc- ture of the atmosphere by spectral analysis to provide preferred modes of motion in the atmosphere in three dimen- sions — latitude, longitude, and altitude; and (3) various time scales indicated to be important by spectral analysis. Geophysical data were checked for accuracy and compara- bility and were summarized statistically in atlases and statis- tical tables. These studies contribute significantly to the design and building of equipment and structures exposed to environ- mental stresses — for example, rockets, launching facilities, supersonic aircraft, and marine equipment. Plans by EDS for a three-dimensional boundary layer climatology in the mesoscale for each major urban area in the United States were made. Such data would afford design criteria for in- 4 121 dustrial development which would be capable of preventing serious degradation by the atmospheric environment. This planned climatology involved the National Environmental Satellite Center (NESC) and the National Aeronautics and Space Administration (NASA) with the Department of Health, Education, and Welfare's (DHEW) National Air Pollution Control Control Administration (in coofjeration with the Air Resources Laboratories' (ARL) Cincinnati, Ohio, facility) and with individual Weather Bureau Offices (WBO) having knowledge of local data sources and their peculiarities. Statistical Climatology The program of EDS in statistical climatology focused on the development of statistical methods for climatological analyses to understand the role of the weather factor and its application to design, planning, and decision problems. One of the statistical climatology research projects initiated by EDS involved the cooperation of the NBS on the design of an experiment to relate micrometeorological wind observations to pressures on a building. The approach to this project was to make extremely detailed observations of velocity and pressure over the face of the building and to develop methods for their potential analysis. New methods of extreme value statistical theory have been developed for application to the calculation of design snow loads, wind loads, and ocean wave heights. Probability theory was also developed to obtain tornado design data for power lines and nuclear reactors. Statistics on storm and tornado damage to buildings and on mortality rates were studied to explain trends. The NWRC initiated a 6-year project with EDS during the reporting period involving research on ways to prepare a global atlas of clear air turbulence (CAT). This project involves the collection of background literature on CAT; development of ideas and concepts for global presentation; collection of CAT data; and preparation of local, geographi- cal, regional, continental, marine, hemispheric, and global presentations. Aeronomy and Space Data The Aeronomy and Space Data Center in Boulder, funded by EDS, conducts research into aeronomy and space data systems with the objective of developing improved methods for collection, standardization, archiving, retrieval, and pub- lication of such upper atmosphere geophysics data as aurora, airglow, cosmic rays, ionosphere, and solar activity. Re- search by the Center is sponsored by the NAS program for WDC-A, and involves the Steering Committee of the Inter- national Ursigram and World Days Service (lUWDS). In- vestigations are underway on the development of systematic methods to implement decisions of the various international scientific unions concerning coordination and implementa- tion of international data interchange. Scientific Information Development The principal developmental effort of SIDD since the formation of ESSA in July 1965 has been the long-range development of a science information system to include the three major ESSA libraries — Atmospheric Sciences Library (ASL), Geophysical Sciences Library (GSL), and Boulder Laboratories Library (BLL) — and serve all of ESSA's re- search laboratories and centers; major regional or State operational centers and public service offices; and ultimate- ly, ESSA's hundreds of individual field stations, units, or survey ships. In November 1967, the Scientific Information and Docu- mentation Council of ESSA adopted a policy definition of an ESSA Library System as a network of libraries and col- lections of published technical information and data among ESSA elements throughout the 50 States. Basic to the effectiveness of the System is coordinated interaction, within and between lib'^aries and collections of different types, guided by the Libraries Branch of SIDD. Interlinking of the major scientific libraries, large spvecial- ized collections at research centers and laboratories, and regional libraries would be aided by the availability of appropriate computer-stored inventories of holdings in the constituent libraries. The Council also directed SIDD to develop a plan for an overall ESSA Environmental Science Information System, including the ESSA Library System. During the reporting period, a number of steps were taken toward that goal. In 1968, a survey of the ASL and GSL in the metropolitan Washington area was made by consultants from the Univer- sity of Maryland Library School. The resulting report has served SIDD as a general guide for possible priorities in its long-range development of the ESSA Library System as a component of an ESSA Environmental Science Information System. A sampling consisting of 3,000 oceanographic holdings from the catalogs of ESSA's three major libraries — ^ASL, GSL, and BLL — ^was put into machineable form by a con- tractor, and listings were made by a number of different methods — that is, by library (chronologically) ; author and title; corporate author; contract, grant, or project number; subject heading; Universal Decimal Classification (UDC) class number (form, place, language, and subject) ; and keyword-in-context (KWIC). Multiple copies of the com- puter printout of the listings were reproduced in four vol- umes and sent to such potential users as libraries and labo- ratories for feedback and suggestions. Several applications of computer manipulation and print- out of records and direct tape-typewriter reproduction in- volving ESSA publications, announcements, research-in- progress reports, and vocabularies were under development. A plan for a comprehensive ESSA Environmental Science Information System was developed for implementation by the Scientific Information Systems Branch of SIDD. This plan recommends the integration of various types of environ- mental science information into a common system accessible to users of all types in laboratories, field stations, or offices, and eventually by high-speed communications facilities where available. 122 The System is to be tailored for the special users oi in- formation from the disciplines of environmental science, but can be integrated with national and international systems and other specialized systems such as university or educa- tional networks in peripheral and core fields of interest. Conventional forms of dissemination will be byproducts for retrospective usage or for dissemination to users not having direct access to on-line facilities. During FY 69, SIDD assumed responsibility for the ESSA Research and Technology Information System, giv- ing recognition to the importance of documenting current research in progress, in addition to publishing results of past research in the ESSA Environmental Science Informa- tion System. The research resumes are used for program re- view and scientific information purposes, both within ESSA and as part of a Government-wide research data bank. Because of its parallel responsibility for the storage, retrieval, and dissemination of environmental science infor- mation in raw or tabulated form, EDS has made or con- tracted studies during the reporting period on the overall data and information indexing problem to acquire better access to the billions of data bits accumulated in both machineable and potentially machineable form. The studies have attacked two problems under the con- cept of "Endex": (1) the overall data access problem where thousands of special types of data are involved; and (2) the terminology or classification problem for description and recall of specific data by subject, time period, and place. These problems involve an interface between raw data in machineable or nonmachineable form and published or sum- marized data supplementing the raw data, or vice versa, depending on the purpose for which the data are required. GLOSSARY OF ACRONYMS ACSO Agricultural Climatology Service Office ADP Automatic data processing ADTECH Administration and Technical Services, Office of AEC Atomic Energy Commission AFO Agricultural Forecast Office AL Aeronomy Laboratory AMOS Automatic Meteorological Observing Station AMVER Automated Merchant Vessel Reporting AOL Atlantic Oceanographic Laboratories APCL Atmospheric Physics and Chemistry Laboratory APT Automatic Picture Transmission ARATOL Air Resources Atmospheric Turbulence and Diffusion Laboratory ARL Air Resources Laboratories ARPA Advanced Research Projects Agency ARS Agricultural Research Service ASL Atmospheric Sciences Library ASO Agricultural Service Office ATEX Atlantic Trade Wind Experiment ATS Applications Technology Satellite AWS Agricultural Weather Services BLIP Boundary Layer Instrument Package BLL Boulder Laboratories Library BOMAP Barbados Oceanographic and Meteoro- logical Analysis Project BOMEX Barbados Oceanographic and Meteoro- logical Experiment CARF Central Airspace Reservation Facility CAT Clear air turbulence CDA Command and Data Acquisition C&GS Coast and Geodetic Survey COSMOS Coast Survey Marine Observation System DACAN Data Acquisition and Analysis DASA Defense Atomic Support Agency DHEW Department of Health, Education, and Welfare DOA Department of Agriculture DOC Department of Commerce DOD Department of Defense DOT Department of Transportation ECCRO Eastern Caribbean Cooperative Reconnaissance Operations EDL Equipment Development Laboratory EDS Environmental Data Service EML Earthquake Mechanism Laboratory EMSU Environmental Meteorological Support Units ETAC Environmental Technical Applications Center ESQ Environmental Sciences Group ESL Earth Sciences Laboratories ESSA Environmental Science Services Administration ESSA Environmental Survey Satellite FAA Federal Aviation Administration FAO Food and Agriculture Organization FCST Federal Council on Science and Technology FOFAX Forecast Office Facsimile FOSDIC Film-Optical Sensing Device FSS Flight Service Stations GARP Global Atmospheric Research Program GFDL Geophysical Fluid Dynamics Laboratory GMD Ground-based Meteorological Detector GMT Greenwich Mean Time GOES Geostationary Operational Environmental Satellite GSL Geophysical Sciences Library HE High frequency HRIR High Resolution Infrared Radiometer HUD Housing and Urban Development, Department of lAGA International Association of Geomag- netism and Aeronomy ICAO International Civil Aviation Organization lER Institutes for Environmental Research IFR Instrument Flight Rules IGOSS Integrated Global Ocean Station System IGRF International Geomagnetic Reference Field IGY International Geophysical Year ITC Intertropical Convergence Zone ITL Ionospheric Telecommunications Laboratory ITOS Improved TIROS Operational Satellite ITPR Infrared Temperature Profile Radiometer ITS Institute for Telecommunication Sciences ITU International Telecommunications Union lUWDS International Ursigram and World Days Service 123 124 JORG Joint Oceanographic Research Group KMRD Key to Meteorological Records Documentation KWIC Keyword-in-context LASA Large Aperture Seismic Array LEDR Laboratory for Environmental Data Research LF Low frequency Lidar Light detecting and ranging Loran Long-range aid to navigation MIT Massachusetts Institute of Technology MLC Major Line Component MRIR Medium Resolution Infrared Radiometer MSL Meteorological Satellite Laboratory MWS Marine Weather Service NADWARN Nationwide Natural Disaster Warning NAE National Academy of Engineering NAPCA National Air Pollution Control Administration NAS National Academy of Sciences NASA National Aeronautics and Space Administration NAVAID Navigation aid NBS National Bureau of Standards NCAR National Center for Atmospheric Research NEIC National Earthquake Information Center NESC National Environmental Satellite Center NHC National Hurricane Center NHRL National Hurricane Research Laboratory NMC National Meteorological Center NODC National Oceanographic Data Center NOMSS National Operational Meteorological Satellite System NRC National Research Council NSF National Science Foundation NSSFC National Severe Storms Forecast Center NSSL National Severe Storms Laboratory NWRC National Weather Records Center ODESSA Ocean Data Environmental Science Services Acquisition OGO Orbiting Geophysical Observatory OPLE Omega Position-Location Equipment OSD Office of Systems Development OSV Ocean Survey Vessels PAGEOS Passive Geodetic Explorer Satellite PATWAS Pilots Automatic Telephone Weather Answering Service PCM Pulse code modulation PDM Pulse duration modulation PE Primitive equation Pibal Pilot balloon POL Pacific Oceanographic Laboratories PWS Public Weather Service RAMOS Remote Automatic Meteorological Observing Station RAREP Radar Report RAWARC RBC RCTM R&D RDO RFC RFF RL RWC SAM SAWRS SDFC SDL SDO SEAMAP SEES SESAME SID SID SIDD SIRS SMS SPDD SSARR sscc SST STD STRS TDL T&EL TICUS TIROS TOS TWEE UDC UHF UN UNESCO USATOPOCOM UT VFR VHF VLF VTPR WB WBFO WBO WBRT WDC WMC WMO WPL XBT RAREP and Warning Coordination Rotating-beam ceilometer Regional Center for Tropical Meteorology Research and development River District Office River Forecast Center Research Flight Facility Research Laboratories Regional Weather Center Subsynoptic advection model Supplementary Aviation Weather Reporting Stations Space Disturbance Forecast Center Space Disturbances Laboratory Systems Development Office Scientific Exploration and Mapping Severe Local Storms Systems Engineering Study of Atmos- pheric Measurements and Equipment Standard Instrument Departure Sudden ionospheric disturbances Scientific Information and Documentation Division Satellite Infrared Spectrometer Synchronous Meteorological Satellite Systems, Plans, and Design Division Streamflow Synthesis and Reservoir Regulation Spin-scan cloud-camera Supersonic transport Salinity-temperature-depth Satellite Time Recovery System Techniques Development Laboratory Test and Evaluation Laboratory Tidal Current System Television Infrared Observation Satellite TIROS Operational Satellite Transcribed Weather Broadcasts Universal Decimal Classification Ultrahigh frequency United Nations United Nations Education, Scientific, and Cultural Organization U.S. Army Topographic Command Universal time Visual Flight Rules Very high frequency Very low frequency Vertical Temperature Profile Radiometer Weather Bureau Weather Bureau Forecast Office Weather Bureau Office Weather Bureau Radiotheodolite World Data Center World Meteorological Center World Meteorological Organization Wave Propagation Laboratory Expendable Bathythermographs INDEX ACSO {see Agricultural Climatology Service Office) ADP (see Automatic data processing) AEC {see Atomic Energy Commission) AFO {see Agriculture Forecast Offices) AL {see Aeronomy Laboratory) AMOS (see Automatic Meteorological Observ- ing Station) AMOS III-70 (see Automatic Meteorological Observing Station) AMVER (see Automated Merchant Vessel Re- porting System) AOL (see Atlantic Oceanographic Labora- tories) APCL (see Atmospheric Physics and Chem- istry Laboratory) APT (see Automatic Picture Transmission System) ARL (see Air Resources Laboratories) ARPA (see Advanced Research Projects Agency) ATEX (see Atlantic Trade Wind Experiment) ATS (see Applications Technology Satellites) AWS (see Agricultural Weather Service) Absolute geomagnetic field, 70 Adak, Alaska, 73 Advanced Research Projects Agency, 104 Aerial metric photography, 65 Aerial Photography, 66 Manual of Color Aerial Photography, 66 Aeronautical charting, 12 Aeronautical charts, 61 Aeronomy, 6, 100-102, 115, 121 Aeronomy and Space Data Center, 6, 17, 115- 116, 121 Aeronomy Laboratory, 17, 18, 100-102 Africa Cayar, 82 Somali Coast, 12 Trou sans Fond, 82 Agricultural climatology, 119 Agricultural Climatology Service Office, 5, 119 Agricultural Experiment Station, 23 Agricultural Forecast Offices, 22 Agricultural Research Service, 59 Agricultural Weather Services, 44—45 Agriculture Frost damage control, 45 Irrigation needs, 45 Water use predictions, 45 Agriculture-weather relationships, 44 Agrometeorology, 44, 45, 120 Growing degree-day studies, 120 Air pollution, 23, 45-48, 49 Climate modification, 49 Diffusion models, 46 Forecasting techniques, 46 Plume dispersion, 46 Plume transport, 46 Research and development, 46, 49 Stagnation index models, 46 Urban building effects, 47 Weather modification, 49 Air pollution— climatology relationships, 46 Air pollution meteorology Research and development, 46 Air Resources Laboratories, 17, 27, 34, 46-48, 100, 101, 121 Airborne IR-measurement techniques, 49 Airborne remote sensors, 60 Airborne sampling instrumentation, 50 Airflow, 100 Alaska, 2, 73, 79, 81, 94, 100, 103, 104, 117 Palmer Observatories, 73 Palmer Regional Tsunami Warning Sys- tem, 73 Albuquerque, N. Mex., 63 Aleutian Islands, Alaska, 75, 79 Aleutian Trench, 81 Alpine and Arctic Research Institute, 49 Amazon Canyon, Brazil, 82 Analytical aerotriangulation, 65, 66 Anchorage, Alaska, 2, 103 Antarctica, 49, 68, 104 Applications Technology Satellites, 3, 4, 12, 13, 14, 25, 38, 39, 87, 105, 106, 109, 110 Air-sea interaction data, 12 Humidity estimates, 4 Hurricane photography, 4 Oceanic-meteorologic data, 87 Storm forecasting, 109 Applied meteorology, 31 Arctic, 117 Asheville, N.C., 113 Atlantic Oceanographic Laboratories, 17, 57, 81, 82, 86, 88-90 Atlantic Trade Wind Experiment, 49, 90 Atmosphere Atomic oxygen detector, 101 E-region, 100 High frequency radio noises, 94 Propagation experiments, 97 Radiant flux, 110 Refractive index, 66 Satellite tracking systems, 97 Sounding data, 112 Vertical temperature profile, 112 Atmospheric circulation Anomalous, 32 Numerical simulation, 32 Persistence, 32 Stratosphere, 32 Tropical disturbances, 32 Troposphere-stratosphere, 32 Atmospheric collision processes, 100 Atmospheric diffusion Stack plumes, 48 Atmospheric disturbances, 21 Atmospheric dynamics, 42 Atmospheric particulates, 103 Atmospheric Physics and Chemistry Labora- tory, 17, 27, 48-51 Atmospheric pollution, 46 (see also Air pollution) Atmospheric radio noise, 13 Atmospheric refractive index, 66 Atmospheric turbulence, 48 Atmospherics, 93 Atomic Energy Commission, 7, 11, 24, 46 Aurora, 100 Australia, 64, 75, 82 Automated Merchant Vessel Reporting Sys- tem, 55 Automated terminal forecasts, 53 Automatic data processing, 15-16 Program management, 16 Automatic drafting machine, 66 Automatic Meteorological Observing Station, 10, 34 Automatic Picture Transmission System, 105, 106, 108 Aviation meteorology Ceiling measurements, 53 Visibility measurements, 53 Aviation Severe Weather Watches, 38 Aviation weather observations, 52 Aviation Weather Reporting Stations, 28 Aviation Weather Services, 22, 52-54 Aircraft operation hazards, 52 Aviation weather data, 53 Pilot briefings, 53 Research and development, 53 BOMAP (see Barbados Oceanographic and Meteorological Analysis Project) BOMEX (see Barbados Oceanographic and Meteorological Experiment) Barbados, 90 Barbados Oceanographic and Meteorological Analysis Project, 8 Barbados Oceanographic and Meteorological Experiment, 6-9, 49, 88, 90 Basic communication network, 28 Basic observation network, 27 Bathymetric mapping, 82, 85 Bathythermographic studies, 88 Benchmark air-sampling stations, 49 BENHAM events, 75, 77 Bering Sea, 12 Bering Sea studies, 87 Bioclimatology Agricultural program planning, 118 Research, 118 Birdlings Flat, New Zealand, 101 Boolean predictors, 53 125 126 BOXCAR events, 75 Brazil, 82 British Research Vessels Hydra, 90 Buoy systems, 112 CAT (see Clear air turbulence) C&GS (see Coast and Geodetic Survey) COSMOS (see Coast Survey Marine Observa- tion System) Canada, 104 Canadian High-Altitude Forecast Center, Mon- treal, Quebec, 53 Canadian National Research Council, 42 Cape Verde Islands, 90 Caribbean Sea, 82 Cartography, 12, 22, 61-62, 65, 79-80, 84 Aeronautical Charts, 79 Airport Obstruction Charts, 22, 65, 80 Automated charting, 84 Computer systems, 80 Controller Charts, 80 Instrument Charts, 79 Research and development, 80 Standard Instrument Departure charts, 80 Visual Charts, 79 World Aeronautical Charts, 79 Ceilometers, 53, 54 Rotating beam, 54 Central North Pacific Magnetic anomalies, 81 Topographic data, 81 Ceylon Submarine canyons, 82 Chesapeake Bay morphology, 82 Clear air turbulence, 21, 53, 54, 121 Climate-man effects, 118 Climate modification, 48 Climatological data Archives, 117 Cloud cover, 5 Global climate, 9 Storm surges, 40, 41 Climatological Data Services, 113 Climatology Climate change, 118 Long-range evolution, 33 Nevada nuclear test site, 47 Research, 118 Research and development, 26 Cloud climatology Cloud forecasting, 31 Global charts, 106 Cloud forecasting, 31 Cloud seeding, 49, 50 Clouds Automated measurements, 54 Brightness charts, 106 Cirrus plumes, 14 Computer mapping, 14 Growth, 10 Hail modification, 10 Mesoscale systems, 10 Picture mosaics, 108 Radio absorption, 13 Seeding, 10 Spin-scan cloud-cameras, 13, 109 Stereophotogrammetric techniques, 10 Vertical motion measurements, 14 Cloudy sky, 3 Coast and Geodetic Survey, 1, 2-3, 11-12, 15, 18-19, 22, 23, 28, 61-68, 70-73, 75, 77- 80, 83-88 Aeronautical navigation charts, 22 Airport Obstruction Charts, 22, 65, 80 Cartographic techniques, 62 Charting, 61-62 Computer cartography, 3 Declination charts, 68 Horizontal control survey networks, 62 Hydrographic data acquisition system, 84, 85 Magnetic charts, 68 Mapping control, 2 Mapping services, 61 National mapping program, 61 Ocean-going vessels, 83 Office of Hydrography and Oceanography, 22 Research and development, 61 Seismic disturbances, 22 Seismic risk maps, 77 Systems analysis, 18-19 Systems development, 18 Tide gage monitors, 83 Vertical control survey networks, 62 Coast Survey Marine Observation System, 87, 88 Ocean tide measurements, 87 Coastal boundary surveys High-water lines, 65 Mean low-water lines, 65 Tidal datum planes, 65 Coastal flood studies, 65 Coastal inundation mapping, 65 Coastal mapping, 64, 84 Cobb Seamount, 81 Columbia River Basin; 59 Communications Data transmission, 29 Display equipment, 29 Global networks, 29 Communications networks, 28 Communications technology, 94 Computer services Ionospheric studies, 104 Computerized ionospheric data, 104 Computers Time-sharing, 55 Condensation nuclei, 9 Continental Shelf, 12 Convection, 33 Convective storms, 99 Crustal movement surveys, 63 Cyclonic storms, 9 D DACAN (5ee Data Acquisition and Analysis System) Data acquisition Severe local storms, 43 Data Acquisition and Analysis System, 75 Data systems development, 117 Denver, Colo., 77 Department of Housing and Urban Develop- ment, 10, 65 Doppler radar, 39, 43, 50, 99 Atmospheric phenomena, 99 Meteorological studies, 99 X-band, 99 Drought Northeastern U.S., 33 E ECCRO (see Eastern Caribbean Cooperative Reconnaissance Operations) EDL (see Equipment Development Labora- tory) EDS (see Environmental Data Service) EML (see Earthquake Mechanism Labora- tory) ESL (see Earth Sciences Laboratories) ESS A (see Environmental Science Services Administration, and Environmental Survey Satellite) ETAC (see U.S. Air Force, and Environmental Technical Applications Center) Earth Core hydrodynamics, 70 Crust, 61 Deep interior, 61 Gravity field, ,64 Magnetic field, 11, 61, 68 Magnetic field source, 68, 70 Physical description, 61 Physical structure, 73 Surface temperature, 110 Earth-air interactions, 1 Earth boundary layer Convection, 33 Earth Description Services, 20, 61-82 Physical parameters, 20 Earth sciences Geodesy, 23 Geomagnetism, 23 Research programs, 23 Seismology, 24 Earth Sciences Laboratories, 12, 17, 68-71, 73-78, 94 * Earth structure Creep measurements, 76 Creep-measuring stations, 77 Plate tectonic concepts, 82 Strain measurements, 76 Earthquake hazards, 77 Earthquake Mechanism Laboratory, 73-78 Earthquake mechanisms, 73, 75, 76 Earthquake-resistant structures, 71, 77 Earthquakes, 3, 10-11, 61, 71-79 Building codes, 78 Caracas Valley, 11 Damage data, 61 Data acquisition, 71 Epicenter studies, 75 Hypocenter determinations, 71 Illinois, 3 Instrumentation, 61 Intensities, 61 Locating procedures, 75 Prediction, 11, 76 Prediction systems, 73 Tsunami generation, 73, 79 Underwater, 73 Eastern Caribbean Cooperative Reconnais- sance Operations, 41 Edinburgh, Scotland, 75 Eielson AFB, Fairbanks, Alaska, 94 Ekman layers, 33 Electrolytic Hydrogen Generator, 35 I 127 Electromagnetic interference, 96 Electromagnetic spectrum, 25, 92 Electromagnetic wave propagation, 92 Endex, 122 Environmental Data Processing Systems, 6 Environmental Data Service, 1, 5-6, 9, 15, 20, 22-23, 26, 37, 58, 72, 84, 106, 113-121 Automated information retrieval, 26 Automated information storage, 26 Data retrieval, 20 Historical records, 22 Research and development, 26 Environmental information dissemination, 28 Environmental Satellite Services, 20, 105-112 Environmental observations, 20 Environmental Science Information System Information indexing problems, 122 Environmental Science Services Administration Air pollution, 23 Computer-stored inventories, 121 Data dissemination, 114 Data retrieval systems, 116 Data services, 104 Economic development, 21, 22 Funding programs, 19 Geodetic programs, 62 Geological Survey, cooperation with, 2, 60 Information services, 113 Information systems, 121 Instrumentation, 104 Marine geophysics, 62, 80 Mission responsibility, 15 National Earthquake Information Center, 61 Natural hazards warning, 19, 21 Organizational structure, 1, 15 Photogrammetry programs, 62 Physical environmental quality, 21 Research and development, 6, 15, 21, 23, 29 Research programs, 20 SEAMAP program data, 88 Test facilities, 29 World Data Center for Seismology, 61 Environmental Sciences Group, 1 Environmental Survey Satellite, 4, 25, 38, 40, 105, 109 Computer mosaics, 4 Environmental Technical Applications Cen- ter, 6 Equipment Development Laboratory, 34, 35, 43, 54, 55 Evaporation, 60, 120 Salton Sea, Calif., 60 Evaporimeters, 60 Evapotranspiration, 120 Exosphere, 13, 100, 103 Extended forecasting, 30 FA A (see Federal Aviation Administration) Fairbanks, Alaska Flood, 2 Hydrological data, 2 Fault systems Calaveras, Calif., 77 Hayward, Calif., 63, 77 Hollister, Calif., 63 Imperial Valley, Calif., 2 Murray Fracture Zone, 81 Salinas River Valley, Calif., 63 San Andreas, Calif., 2, 11, 63, 76, 77 San Joaquin Valley, Calif., 2, 63 Seamap Channel, 81 Federal Aviation Administration, 28, 38, 53, 54, 64, 73, 79, 80, 113 Federal Aviation Meteorological Service Planning guidelines for a, 52 Federal Bureau of Investigation National Crime Information Center, 96 Federal Republic of Germany, 64 Fire Weather Service, 51-52 Federal agency use, 51 Research and development, 51 Flood forecasting, 110 Flood forecasts, 57 Flood prediction and warning, 20, 57-60 Floods Damage, 57 River forecasts, 57 Florida, 9, 65, 82, 88 Florida Cumulus Seeding Program Condensation nuclei, 9 Florida Current variability, 88 Fluid dynamics Laminar fluid flow, 33 Forecast data dissemination, 58 Forecast organization, 18 Forecasting development Numerical weather prediction, 29 Prediction model, 29 Forecasting services, 20, 27 Research and development, 27 River and floods, 20, 57-60 Water supply, 20 Forecasting techniques Airport terminal weather, 53 BOMEX, 6 Computer forecasts, 2 Computer uses, 104 Fire weather, 5, 52 Flood, 10 Marine environment, 55 Marine surface conditions, 56 PE numerical model, 9 Pollution potential, 46 Quantitative precipitation, 35 Severe local storms, 2 Severe storms, 39 Shipping routes, 54 Short-period, 37 Snowmelt rate, 10 Solar flare activity, 6 Space disturbances, 6 Statistical methods, 31 Surface circulation, 9 Sverdrup-Munk-Bretschneider method, 56 Temperature, 42 Three-dimensional trajectory model, 42 Thunderstorms, 43 Tornadoes, 2, 42 Verification experiments, 31 Visibility, 9, 37 Waves and surf, 57 Weather, 117 Weather analysis, 9 Wind waves, 56 Forest Service, 51 Fort Churchill, Canada, 103 Frontal dynamics, 33 GARP (see Global Atmospheric Research Program) GFDL (see Geophysical Fluid Dynamics Lab- oratory) GOES (see Geostationary Operational En- vironmental Satellite) Gaithersburg, Md., 64 Galapagos Islands Caldera explosion (June 1%8), 99 Geoacoustics research, 99-100 Infrasonic stations, 100 Geodesy, 11, 61, 62-67 Gravitational harmonics, 11 Horizontal control networks, 67 Research and development, 66 Satellite geodetic research, 66 Geodetic data, 62 Geodetic surveys Bench marks, 63 Monumented triangulation stations, 63 Geoid profiles, 64 Geomagnetic data, 61 Geomagnetic Data Center, 114 Geomagnetic field, 70 Prediction, 61 Secular change, 70 Geomagnetic observations, 71 Geomagnetism, 11-12, 61, 68-71 Earth's magnetic field, 11, 12 Equatorial electrojet, 70 Magnetic observatories, 68 Paleomagnetic studies, 12 Research and development, 61 World Data Center, 68 Geometric satellite programs, 66 Geophysical data, 104 Geophysical Data Centers, 114 Geophysical environment, 98 Geophysical Fluid Dynamics Laboratory, 17, 27, 30, 31-32, 33-34, 38, 86, 88-89 Geophysical maps, 85 Geophysical measurements Nuclear detonations, 104 Research and development, 104 Geophysical phenomenon monitoring, 77 Geophysical sensors, 104 Geopiezomagnetism Variations, 71 Geostationary Operational Environmental Satellite, 13, 14, 25, 106 Geotectonics Continental drift, 81 Sea-floor spreading, 81 German Research Vessels Meteor, 90 Planet, 90 Global air pollution, 118 Global Atmospheric Research Program, 6, 8 Global climatology, 120 Global diffusion Long-lived radioactive debris, 47 Long-range diffusion, 47 Plume behavior, 47 Research, 47 Global Solar Flare Patrol Network, 6, 104 Grand Coulee Dam, Wash., 71 Gravity, 64 Gravity anomalies, 67 Great Lakes Erie, 49, 56, 57 Ice charts, 108 Ice conditions, 54 Ontario, 49 Shipping forecasts, 54 Wind-wave forecasting, 56 128 Great Lakes Program Snow redistribution, 9 Guam, 68 GuU Stream, 14, 88, 89, 112 H HRIR (see High Resolution Infrared Radiom- eter) HUD {see Department of Housing and Urban Development) Hail storms, 48 Hawaii, 37, 38, 49, 63, 73, 79, 81, 120 Energy budget, 120 Hawaiian Ridge, 81 High-Precision Transcontinental Traverse Net- work, 63, 67 High Resolution Infrared Radiometer, 14, 26, 40, 110 Sea-surface temperature, 14 Holloman AFB, N. Mex., 63 Houston, Tex., 63 Hurricane forecasting, 39 Hurricane Warning Service, 38 Hurricanes, 4, 9, 24^25, 38-42, 109 Alma (1962), 41, 42 Betsy (1%5), 42 Cooperative reporting networks, 38 Forecasting, 39, 42, 109 Hilda (1%4), 41 Inez (1%6), 40, 41 Modification experiments, 41 Project Stormfury, 41 Research, 24-25 Research and development programs, 38 Satellite observations, 40 Simulation experiments, 41 Structure, 41 Verification programs, 41 Hydrographic surveys, 84 Hydrography, 83-85 Hydrological data, 2, 84 Hydrological models, 59, 60 Stanford Watershed, 59, 60 Streamflow hydrograph, 59 Hydrological services, 22, 58, 60 Flood forecasting, 22, 58 Hydrology, 2, 10, 16, 20, 22, 57-60, 110 Applied satellite data, 16 Data collection, 58, 60 Flash-flood alarm gage, 60 Research and development, 59, 60 River forecasting, 59 Satellite data collection, 60 Hydromagnetism, 70 Hydrometeorological studies, 20, 59 lAGA {see International Association of Geo- magnetism and Aeronomy) ICAO {see International Civil Aviation Or- ganization) lER {see Institutes for Environmental Re- search) IGY {see International Geophysical Year) IGOSS (see Integrated Global Ocean Station System) ITC {see Intertropical Convergence Zone) ITL (see Ionospheric Telecommunications Laboratory) ITOS {see Improved TIROS Operationa; Satellite) ITPR (see Infrared Temperature Profile Radiometer) ITS (see Institute for Telecommunication Sciences) Ice conditions Great Lakes, 54 Polar seas, 54 Iceland, 104 Idaho, 71 Improved TIROS Operational Satellite, 5, 14, 25, 105 Moisture profiles, 14 India Bombay, 12 Indonesia, 81 Information transmission, 95 Infrared Temperature Profile Radiometer, 13- 14, 26, 112 Infrared photography, 64 Institute for Telecommunication Sciences, 17, 18, 66, 92-97 International Association of Geomagnetism, and Aeronomy, 12, 70 Institutes for Environmental Research, 1, 17 International Civil Aviation Organization, 53 Intergrated Global Ocean Station System, 94 International Geophysical Year, 115 International Polar Motion Service, 64 Interoceanic Canal meteorology, 48 International communications networks, 28 Intertropical Convergence Zone, 32 Ionosphere, 13, 43, 91, 92-94, 100, 103, 104 Antarctic, 103 D-region, 100, 103 Electron content, 103 Electron density, 13, 94 F-region, 101, 103 Global variations, 94 Magnetic equator, 100 Radio wave transmission, 91 Rocket studies, 100 Satellite studies, 100 Short-term changes, 103 Short-term variations, 94 Telecommunications programs, 92 Topside, 100 Ionosphere-atmospheric waves interactions, 93 Ionospheric backscatter, 93 Ionospheric currents modification, 94 Ionospheric drifts, 101 Ionospheric predictions, 94 Ionospheric Telecommunications Laboratory, 43 Isogriv charts, 68 JORG (see Joint Oceanographic Research Group) Jicamarca, Peru, 101 Joint Oceanographic Research Group, 88 LASA {see Large Aperture Seismic Array) LEDR (see Laboratory for Environmental Data Research) Lidar {see Light detecting and ranging) Loran (see Long-range aid to navigation) Laboratory for Environmental Data Research, 117-120 Lake Erie Winds, 57 Land gravity surveys, 64 Land-sea interaction, 83, 89 Langmuir probe, 101 Large Aperture Seismic Array, 75 Laser sources, 98 Latitude observatories, 64 Lava tubes caverns, 71 Light detecting and ranging, 46, 54, 112 Lightning, 43 Lightning suppression, 9, 48-49 Lightning Suppression Project Thunderstorms, 9 Lima, Peru, 101 Long-range aid for navigation Loran-C, 9, 35, 66-67 Loran-D, 93 Louisiana Dept. of Highways, 66 Lunar albedo, 101 Lunar-solar gravitational tide, 34 M MIT (see Massachusetts Institute of Tech- nology) MRIR (see Medium Resolution Infrared Radiometer) MSL (see Meteorological Satellite Laboratory) MWS (see Marine Weather Service) McMurdo Sound, Antarctica, 102 Magnetic charts, 68 Isogriv charts, 68 Magnetic data analysis, 68 Magnetic declination, 68 Magnetic equator, 100 Magnetic field, 11-12, 70-71 Historical period, 1725-1%5, 70 Variations, 70-71 Magnetic observatories, 61, 68 Magnetic spatial noise, 71 Magnetosphere Boundary, 103 Magnetosheath, 103 Mann comparator, 67 Manual of Color Aerial Photography, 66 Marine Description Services, 20, 83-90 Marine environmental conditions, 55 Marine geomagnetic surveys, 68 Marine geophysics, 62, 80-82 Bathymetry, 81 Geotectonics, 81 Land-sea boundary studies, 80 Ocean basin characteristics, 81, 82 Research and development, 80 Suboceanic structure studies, 81 Marine gravity surveys, 64 Marine morphology Bathymetric maps, 82 Upper Mantle Project, 82 Marine navigational charting, 83-85 Nautical charts, 83 Research and development, 84-85 Marine observation systems Buoys, 87 Deep underwater platform, 87 Marine Resources and Engineering Act, 55 129 Marine warnings, 54, 55 Marine Weather Services, 22, 54-57, 84 Forecasting for coastal waters, 54 Forecasts, 54 Ice conditions advisories, 54 Marine warnings, 55 Research and development, 54 Massachusetts Institute of Technology, 32 Mathematical Geodesy, 11 Mathematical magnetic models, 70 Medium Resolution Infrared Radiometer, 110 Mesoclimatology, 120 Meteorological Satellite Laboratory, 17 Meteorological satellites Illumination measurements, 120 Meteorological statistics studies Tidal relationships, 34 Meteorology, 9-10, 21-23, 24-25, 27-60, 101, 106-112 Atmospheric dynamics, 24 Clear air turbulence, 54 Research and development, 24 Thermal convection, 9 Meteorology-nuclear tests effects, 47 Microwave sensing, 112 Model atmosphere, 3 Montana State University, 119 Mountain wave turbulence forecasts, 54 N NADWARN (^ee Nationwide Natural Disaster Warning System) NAPCA (see National Air Pollution Control Administration) NAS {see National Academy of Sciences) NASA (see National Aeronautics and Space Administration) NBS {see National Bureau of Standards) NCAR (see National Center for Atmospheric Research) NEIC (see National Earthquake Information Center) NESC (see National Environmental Satellite Center) NHC {see National Hurricane Center) NHRL (see National Hurricane Research Laboratory) NMC (see National Meteorological Center) NODC (see Naval Oceanographic Data Center) NOMSS (see National Operational Meteorolo- gical Satellite System) NSF (see National Science Foundation) NSSFC (see National Severe Storms Forecast Center) NSSL (see National Severe Storms Labora- tory) NWRC (see National Weather Records Center) National Academy of Sciences, 48, 67, 114 National Aeronautics and Space Administra- tion, 7, 13, 25, 35, 64, 73, 87, 102, 105, 106, 121 Wallops Island, Va., 35' National Air Pollution Control Administration, 46, 121 National Center for Atmospheric Research, 7, 49 National Bureau of Standards, 66, 117, 121 National Earthquake Information Center, 61, 72 National Environmental Satellite Center, 1, 3-5, 13-14, 15, 22, 23-24, 25-26, 27, 38, 40, 58, 60, 87, 99, 105-112, 121 National Geodetic Network, 63 National Geophysical Data Center, 2, 14 National Hurricane Center, 1, 18, 23, 38, 39-41, 52, 110 National Hurricane Research Laboratory, 9, 17, 27, 38, 39, 41 National Meteorological Center, 1, 2, 3, 4, 9, 18, 23, 27, 29, 30-33, 36, 38, 42, 46, 52, 54, 56, 57 National Oceanographic Data Center, 9, 84, 114-^115 National Operational Meteorological Satellite System 4, 105 National Science Foundation, 7, 68 National Severe Storms Forecast Center, 1, 2, 18, 23, 38, 39, 42, 43, 52, 110 National Severe Storms Laboratory, 17, 27, 39, 42^14, 60 National Transportation Safety Board, 52 National Tsunami Warning Center, 72, 73 National Weather Records Center, 6, 9, 37, 106, 113, 114, 117, 120-121 Nationwide Natural Disaster Warning Sys- tem, 21, 36 Nautical chart construction, 64 Naval Oceanographic Office, 115 Navier-Stokes equation, 70 North Atlantic, 81 North Pacific, 81 Northeast Rain Augmentation Project, 9, 50 Cyclonic storms, 9 Rainmaking, 9 Norway, 75 Numerical prediction PE model, 30 Baroclinic modeling, 30 o ODESSA (see Ocean Data Environmental Science Services Acquisition) OGO (see Orbiting Geophysical Observatory) OSD (see Office of Systems Development) OSV (see Ocean Station Vessels) Observational studies, 33-34 Atmospheric energy conversions, 33 Experiments, 33 Water balance, 34 Ocean-atmosphere system, 33 (see also Sea-air interaction) Ocean circulation, 88-89 Dynamics, 88 Numerical models, 88-89 Ocean Data Environmental Science Services Acquisition, 12, 87, 88 Ocean motion, 87 Semidiurnal internal waves, 87 Ocean Station Vessels, 12, 55 Ocean structure, 87-88 Physical and chemical, 88 Ocean-surface temperatures, 112 Ocean tides measurements, 87 Oceanographic observations, 12, 85 Tidal currents, 85 Tides, 85 Oceanography, 12, 24, 83, 85-90, 112 Applied satellite data, 16 Coastal currents, 83 Coastal tides, 83 Geophysical surveys, 85 Land-sea interaction, 24 Marine mapping, 83 Oceanic vertical speed of sound, 88 Physical properties, 24 Research, 112 Research and development, 83, 86 Sea-air interaction, 24 Tidal currents, 83 Tidal gage networks, 85 Office of Naval Research, 88 Office of Systems Development, 1, 18 Omega, 9, 35 Optical aeronomy, 101 Optical wave propagation, 98 Orbiting Geophysical Observatory, 103 PAGEOS (see Passive Geodetic Explorer Satellite) PE (see Primitive equation) POL (see Pacific Oceanographic Labora- tories) PWS (see Public Weather Service) Pacific Oceanographic Laboratories, 79, 81, 82, 86-88 Pacific Tsunami Warning System, 18, 73, 75, 79 Pahute Mesa, Nev., 75 Paleomagnetism, 70 Palmer, Alaska, 100 Panama Basin, 88 Passive Geodetic Explorer Satellite, 11, 63 Geometric network, 63 Phenological data, 119 Photogrammetric field surveys, 64 Photogrammetry, 62, 64-66 Intercoastal Waterways, 64 Shoreline mapping, 64 Small-Craft Charts, 64 Photosynthesis, 119, 120 Physical environment, 15 Physical environmental quality, 23 Physical oceanography Research and development, 86-90 Piezomagnetic effects, 77 Planetary boundary layer, 46, 48 Plasma physics Research, 100 Plume rise, 48 Precipitation forecasts, 31 Precipitation model Three-layer, 31 Precise alignment survey, 63 Precision-tracking radar, 35 Prediction techniques, 36-37 (see also Weather forecasting) Precipitation, 37 Primitive equation, 2, 29-31, 39, 42, 46, 52 Project ECCRO, 41 Project Stormfury. 41 (see also Hurricanes) Public Weather Service, 23, 27, 36-37 Puerto Rico, 68 Pullman, Wash., 100 Purdue University, 119 Pyranometers, 119 130 R RAMOS (see Remote Automatic Meteorologi- cal Observing Station) RCTM (see Regional Center for Tropical Meteorology) RFC (see River Forecast Center) RFF (see Research Flight Facility) RL (see Research Laboratories) RWC (see Regional Weather Center) Radar attenuation, 60 Radar data Digitization, 43 Rainfall rates, 43 River forecasting, 43 Radar precipitation analysis, 60 Radar scatter studies, 101 Radars Doppler, 43, 50 WSR-57, 43 Radio channels, 97 Radio meteorology, 13, 99 Evaporation determination, 99 Lower atmosphere, 99 Microwave instrumentation, 99 Radio noise measurements, 96 Radio signal propagation, 93 Radio spectrum use, 97 Radio tracking experiments Millimeter-wave sky temi>erature, 97 Radio transmission, 94 Radio wave scattering, 97 Radio waves, 91 Radioheliograph, 104 Radiometers, 112 Radiosonde data, 2 Rain augmentation, 50 Rainfall-runoff relationship, 60 Rainfall data, 50 Raingage data, 50 Raingage instrumentation, 50 Raman backscatter, 35 Rawinsonde data, 35, 43 Semiautomatic computations, 35 Refractive index Geodimeter measurements, 66 Regional Center for Tropical Meteorology, 38 Regional Climatologists, 113 Regional Weather Center, 18 Remote Automatic Meteorological Observing Station, 34 Remote sensing techniques, 112 Remote sensors, 91, 98, 99 Research and development programs, 19-20, 27, 61, 83, 92, 105, 113 Research Flight Facility, 17, 18, 27, 42 Research Laboratories, 1, 6-9, 12, 15, 17-18, 23-24, 25, 27, 30, 31-32, 33-34, 38-44, 46-51, 57, 60, 61, 66, 68-71, 73-79, 81- 82, 83, 86-104, 115, 121 Reservoir evaporation, 99 Rhode Island State Highway Dept., 63 Riometers, 103 River conditions forecasts, 57 River Forecast Center, 4, 43, 58, 59, 60 River forecasts and warning, 20, 57-60 Rocketsonde data, 2 Rockville, Md., 61 Rocky Mountain Arsenal, 77 Rubidium magnetometer, 71 SAWRS (see Supplementary Aviation Weather Reporting Stations) SDFC (see Space Disturbance Forecast Center) SDL (see Space Disturbances Laboratory) SDO (see Systems Development Office) SEAMAP (see Scientific Exploration and Mapping Program) SESAME (see Systems Engineering Study of Atmospheric Measurements and Equip- ment) SID (see Sudden ionospheric disturbance) SIDD (see Scientific Information and Docu- mentation Division) SIRS (see Satellite Infrared Spectrometer) SMS (see Synchronous Meteorological Satel- lite) SST (see Supersonic transport) STD (see Salinity-tertiperature-depth) STRD (see Satellite Time Recovery System) Salinity-temperature-depth, 12, 106 Recorders, 12 Salton Sea, Calif., 60 Sampling programs Antarctica, 49 Mauna Loa, Hawaii, 49 Sampling techniques Instrumentation, 42 Satellite camera systems, 13 Satellite data, 67, 106 Satellite environmental analysis, 109 Satellite Infrared Spectrometer, 3, 13, 26, 109- 112 Nimbus-3, 3, 13 Soundings, 3 Satellite observations, 109 Satellite photography, 106-109 Weather systems tracking, 107 Satellite sensors, 25, 112 Satellite triangulation, 2, 61 Satellites Aerial triangulation, 2, 61 Alouette-1, 13 Alouette-2, 13 ATS, 3, 4, 12, 14, 25, 38, 39, 87, 109 ATS-1, 13, 25, 105, 106, 109 ATS-3, 13, 25, 105, 106, 109, 110 Data reduction, 67 ESSA, 4, 25, 38, 40, 105, 109 Explorer-20, 13 Geodetic data, 62, 67 GOES, 13, 14, 25, 106 Hydrologic data collection, 60 Ionosphere studies, 100 ITOS, 5, 14, 25, 105 Nimbus, 25 Nimbus-2, 40 Nimbus-3, 3, 13 Nimbus-D, 13 PAGEOS, 11, 63 Pioneer-7, 103 SMS, 13, 106 Terrestrial gravity data, 67 TIROS, 25, 105 TIROS-M, 5 TOS, 25, 105 Vela, 103 Science information, 116, 121-122 Scientific Exploration and Mapping Program, Scientific Information and Documentation Di- vision, 113, 116, 121-122 Sciences Libraries, 121 Scintillation, 98 Scripps Institution of Oceanography, 90 Sea-air interaction, 1, 6, 33, 89 Boundary layer, 89 Indian Ocean, 33 Large-scale evolution, 33 Numerical model, 89 Numerical prediction, 33 Pacific Ocean, 33 Sea-Air Interaction Laboratory, 90 Sea-air model, 12 Sea-and-swell forecasting, 56 Sea floor morphology, 82 Sedimentology, 81-82 Deep sea carbonate deposits, 82 Geochemical studies, 82 Morphological change predictions, 82 Research and development, 81 Submarine sediments, 81, 82 Seismic arrays LASA, 75 Seismic instrumentation Audiometer, 75 Computer facilities, 75 Deep sea tsunami gages, 79 Seismoscopes, 72 Telemetering system, 77 Seismic risk maps, 77 Seismic signal reception, 75 Seismic wave analysis, 73 Seismic waves, 73 Seismograph stations, 2, 75 Seismology, 2, 10-11, 18, 24, 61, 71-79, 114 BENHAM events, 75 BOXCAR events, 75 Crustal plates, 11 Data collection stations, 114 Earth noise studies, 75 Earth structure, 10 Earthquakes, 10 Engineering, 77 Hypocenter determination, 72, 75 Mechanics of earthquakes, 73 Observatories, 71 Observatory networks, 61 Portable seismic instruments, 75 Research and development, 73, 76 Seismograph stations, 2 Tsunami, 10, 18 Vibration damage, 11 World Data Center, 61 Seismometers, 100 Seismoscopes, 72 Sensors, 55, 60 Air temperature, 55 Airborne, 60 Severe local storms Research, 25, 39 Severe storm characteristics, 42 Severe storm programs Cyclonic circulation, 38 Doppler radar system, 39 Forecasting techniques, 39 Local storms, 39 Modification methods, 39 Research and development, 25, 39 Severe storm studies. 21, 25, 39, 42^i5 Lightning, 43 Severe storm warning service, 38 Severe weather watches, 21 131 Sferics, 43 Sitka, Alaska, 73 SKUA rockets, 103 Snow cover depth, 110 Snow load design, 121 Snow measurements, 59 Snow modification Great Lakes region, 49 Snow prediction studies Snowfall patterns, 37 Snowmelt, 58, 59, 60 Energy budget, 60 Forecasts, 58 Problems, 59 Volumetric flow, 58 Soil radiative properties, 120 Soil temperature, 119 Solar activity, 92, 94, 102-104 Data analysis, 104 Terrestrial events, 102 Solar disturbances, 94 Solar flare forecasts, 104 Solar physics Instrumentation, 104 Radio bursts, 104 Solar radiation, 92 Solar radiation prediction, 92 Solar wind, 104 Sonic boom Microphone arrays, 47 South America, 75 South Pacific, 81 Space Disturbance Forecast Center, 6, 102, 104 Solar events, 6 Space disturbances, 13, 91-92, 94, 102-104 Polar cap absorption, 13, 94, 104 Solar flare events, 13, 102, 104 Space Disturbances Laboratory, 17, 25, 102-104 Space Disturbances Monitoring Facility, 6, 103, 104 Space environment, 25, 92, 102-104 Research, 25, 92 Space weather forecasting, 103 Stanford Research Institute, 54 State Climatologists, 113 Statistical climatology, 31, 121 Storm hazards Aircraft safety, 42 Storm surge forecasting, 56 Storm surges, 57, 90 Prediction service, 57 Straits of Florida, 82 Stratosphere, 2, 32, 47, 101 Stratosphere-troposphere interaction, 2 Stratospheric radioactivity Carbon-14 samplers, 47 Iodine-131, 47 Kinematic model, 47 Particulate debris, 47 Radioactive argon-41, 47 Stratospheric warnings, 32 Sudden ionospheric disturbance, 104 Supersonic transport, 2, 25, 54, 92 Supplementary Aviation Weather Reporting Stations, 28 Synchronous Meteorological Satellite, 13, 106 Synoptic climatology, 117 Synoptic weather charts, 2 Systems Development Office, 2, 9, 18, 27, 29, 35, 36, 39, 53, 55, 60 Systems Engineering Study of Atmospheric Measurements and Equipment, 35 TDL (see Techniques Development Labora- tory) T&EL {see Test and Evaluation Laboratory) TICUS (see Tidal Current System) TIROS (see Television Infrared Observation Satellite) TOS (see TIROS Operational Satellite) Tasman Sea, 88 Techniques Development Laboratory, 29-30, 36-37, 42, 52, 53, 54, 56-57 Telecommunications, 6, 13, 20, 23, 25, 91, 92- 100 Digital systems, 96, 98 Electromagnetic spectrum, 20 Electromagnetic waves, 92, 99 Frequency propagation, 92 Goubau line, 94 High frequency propagation, 93 Instrumentation, 99 Loran-D, 93 Millimeter-wave propagation, 99 Optical wave propagation, 13 Radio-circuit predictions, 91 Radio wave propagation, 13 Research and development, 92 Submillimeter-wave i)ropagation, 99 Systems design, 91 VLF signal propagation, 13 Telecommunications and space research Communication technology, 25 Telecommunications and Space Services, 20, 23, 91-104 Upper atmospheric disturbances, 20 Telecommunications Disturbance Forecast Cen- ter, 6, 94 Teleseismic tables, 73 Television Infrared Observation Satellite, 5, 25, 105 Temperature Sea-surface, 5, 9, 14 Tetroon, 47 Test and Evaluation Laboratory, 10, 29, 35, 53-54 Texas A & M University, 119 Thunderstorms, 9, 10, 28, 42, 43, 48 Storm modification, 10 Tidal Current System, 12 Tidal currents, 12 Time studies, 66 TIROS Operational Satellite, 25, 105 Tornadoes, 3, 25, 38, 42-44, 121 Design data, 121 Severe local storms, 42 Warnings, 38 Total weather prediction, 27 Totem Buoy, 57 Travelers Research Corporation, 37 Tree-ring research, 118 Trilateration test net, 66 Tropical atmosphere, 60 Tropical cyclones Climatological track, 39 Models, 41 Observations, 40 Tropical disturbances Africa, 41 Tropical storm modification, 49 Troposphere, 91, 95-100 Communication channel characteristics, 95 Radio wave propagation, 91 Telecommunication systems design, 96 Telecommunications program, 95 Tropospheric physics, 97 Signal phase distortion, 97 Tropospheric propagation predictions, 97 Tropospheric scatter, 97 Tsunami warning system, 61 Tsunamis, 10, 18, 61, 73, 75, 79 Prediction systems, 73 Travel time tables, 79 Warning systems, 61 Turbulence, 42 u USC&GS (see U.S. Coast and Geodetic Survey) Ukiah, Calif., 64 United Kingdom, 64 United States Gulf Stream, 14, 88, 89, 112 Long Island, N.Y., 12 Virginia coast, 12 U.S. Air Force Air Weather Service, 42 Environmental Technical Applications Cen- ter, 6 U.S. Army Topographic Command, 63 U.S. Coast and Geodetic Survey (see a/so Coast and Geodetic Survey) U.S. Coast and Geodetic Survey Ships, 12, 49, 82, 83-85, 90, 92 Discoverer, 49, 90 Ferrel, 85 Oceanographer, 12, 49, 82, 92 Surveyor, 12 Whiting, 84, 85 U.S. Coast Pilot publications, 84 U.S. Naval Observatory, 66 University of Arizona, 118 University of California, 75 University of Hawaii, 37, 79, 120 University of Maryland, 121 University of Michigan, 97 University of Missouri, 120 University of Nebraska, 120 University of Washington, 87 University of Wisconsin, 120 University of Wyoming, 117 Upper air Measuring techniques, 35 Passive microwave techniques, 35 Raman backscatter, 35 Remote-sensing techniques, 35 Wind-finding techniques, 35 Upper air observations Balloon-borne instruments, 9 Satellite-borne instruments, 9 Upper air systems Precipitation forecasts, 35 Upper atmosphere, 13, 25, 32-33, 91, 92, 100- 102 Electron density, 13 Geomagnetic activity, 100 Investigations, 32-33 Stratospheric map analysis, 32 Stratospheric warnings, 32 Upper atmospheric physics, 92 Upper atmospheric research, 25 Upper stratospheric meteorology, 101 y 132 VTPR (see Vertical Temperature Profile Radiometer) Vermont, 63 Vertical Temperature Profile Radiometer, 14, 26 Virginia Beach, Va., 88 Volunteer observation networks, 113 w WB {see Weather Bureau) WDC (see World Data Center) WMC {see World Meteorological Center) WMO {see World Meteorological Organiza- tion) WPL {see Wave Propagation Laboratory) Wallops Island, Va., 106 Warning coordination centers, 36 Warning services, 19, 20, 27, 38 Water balance studies, 34 Water resources management, 118 Wave Propagation Laboratory, 17, 18, 39, 60, 66, 92, 97-100 Weather Plant disease relationships, 45 Small-scale system, 43 Weather Bureau, 1, 2, 9-10, 15, 18, 20, 21, 22, 23, 24-25, 27-46, 51-60, 84, 106, 121 Airport terminal forecasts, 53 Forecast Offices, 18, 21, 36, 42, 46, 53, 54, 106 Hydrological services, 22 International aviation forecasts, 53 Offices, 18, 36, 38, 51, 58, 106, 121 Research and development, 27 Weather forecasting Eighteen-level hemispheric model, 32 Four-dimensional analysis, 31 Large-scale prediction models, 36 Local, 37 Long-range forecasts, 30-32 Nine-level hemispheric model, 31 Numerical prediction projects, 36 Prediction techniques, 36 Public programs, 36 Seasonal, 32 Short-period, 37 Solar-weather analogs, 32 Weather forecasts, 20, 27, 30, 31 Five-day, 30, 31 Hemispheric conditions, 31 Long-range, 30 Thirty-day, 31 Two-week predictions, 31 Weather forecasts and warnings, 20, 27-60 Weather in agriculture, 44 Weather information, 36 Weather modification, 12, 24, 48-51 Air pollution, 49 Hail storms, 48 Hail suppression, 48 Lightning suppression, 48 Research and development, 48 Snow storms, 49 Weather observations Radar, 28 Upper air, 28 Weather radar, 43 Weather sensors Wind, 34 Weather services Automation, 29 Wideband communications, 97 Wind loads, 121 Wind-wave forecasting, 89 Winds, 109 Winds-aloft measurements Loran-C, 35 Omega, 35 Wisconsin, 119 World Data Center, 61, 68, 73, 114, 116, 121 World Meteorological Center, 29 World Meteorological Organization, 6, 28, 54, 60, 104, 119 World Warning Agency, 32 Worldwide Geometric Satellite Network, 63, 67 U.S. GOVERNMENT PRINTING OFFICE: 1970 0—385-915 ^ _) / PENN STATE UNIVERSITY LIBRARIES A0DDD75Da5337