APPENDIX VII

THE INTERNATIONAL GEOPHYSICAL YEAR-PROPOSED UNITED STATBS PBmBAbf

The program for the ASTROOEOPHYSIW BCEASUIULY~I’JT~ International Geophysical year is de- Many of the most practical and enty- scribed by fields below. It envisages ac- lay activities of man and society sure &dies in several geographical regions of affected and determined by astronomical concern to the Nation: ( 1) The Arctic phenomena. Surveying, whether of con* and sub-Arctic regions ; (2 ) the middle tinental coast lines or real estate lo% of the Northern and Southern mapping and charting of land and seas Hemispheres, including the United States, tidal currents, magnetic compass and , , and radio navigation, travel and conune~~ adjacent stretches of the Atlantic and over land, sea, or air, radio communiCa* Pacific Oceans; and (3) the Antarctic tions, typhoons, duststorms and rainless and sub-Antarctic regions. The effort in regions are typical of the activities and these regions varies with present, sustained phenomena that are closely linked to the geophysical activities in each region and sun, moon, and stars. with technical needs. Existing activities The sun, in particular, dominates of the former kind, whose results will be events and activities on the earth. The made available in the program, aflord a 8un’s radiation-electromagnetic and substantial base for the total endeavor, particle-is the major source of energy and the proposed program represents for the earth’s atmosphere and indirectly those added efforts which are required for all types of life on this planet. Some for advances in geophysics expected from solar effects are obvious to the layman- a major United States activity, in com- the gross diurnal variations in weather bination with similar special. and ex- phenomena, the weather changes by sea- panded investigations by other nations. sons, the temperature differences between Emphasis of much of the program is the and the poles. Solar varia- upon the Arctic and sub-Arctic, Antarctic tions are not particularly important in and sub-Antarctic, a few zones in South these connections. Less obvious but of America, and the Atlantic and Pacific equally great significance to modem Oceans. It is not necessary, in many of civilization are the effects of solar activity the programs, to add much activity within on the upper atmosphere. Unusual solar the United States, for normal operations radiation, either in intensity or in kind; provide this data. For example, the strongly influences the upper atmosphere meteorology program includes only a few and, indirectly, not only weather phe- South American stations and work in the nomena but radio communications, radio Antarctic. The data from these regions, navigational systems, and many other added to those from existing Weather civilian and military activities, Bureau stations in the United States and Solar activity has several time scales: in the regions, will provide Overall activity, measured in a number adequate coverage for the crucial experi- of ways, grows and subsides alternately in ments planned in the Western Hemis- about 11 years-the “sunspot cycle.” phere. Similarly, the ionospheric, auro- Individual active regions on the sun, ral, and geomagnetic programs stress the sometimes marked by sunspots, have life- northern and southern latitudes. times of a few days to a few months, 820814--5B---10 128 124 NATIONAL SCIENCE FOUNDATION

changing rather gradually during thai The IGY also &ords an opportunity to time. Spurts of activity, occasionally achieve a marked advance in during “sunspot minimum” but common and measurements. There are during the high activity stages of the 1 l- two kinds of longitude and latitude: Geo- year cycle, occur in some individual solar graphic and astronomical. Geographic regions and last a few hours or a few coordinates must be used in mapping and days, with individual outbursts or flares can only be obtained for the earth as a lasting only 10 to 30 minutes or so. whole by observing the moon or by meas- Variation in solar activity on each of urements of gravity all over the earth, these time scale8 have been shown to be which have never been adequately ob- associated with terrestrial phenomena. tained. Astronomical coordinates can be Many details of these correlations, how- determined accurately only by observing ever, remain hazy because of the many the stars. While these are not useful for interruptions in the record of solar activity making maps, their high precision makes observations. Further ‘correlations of them useful for detecting a possible shift broad implications to science and civilixa- in the distance between two land masses. tion require detailed and comprehensive The and latitudes of numer- records of solar activity. The chief aim ous points in all civilized countries have of the solar activity work during the IGY been accurately measured so that accurate is to achieve this record by systematic ob- maps of large regions have been possible. servations of the sun, through improved But it has not been possible to extend the coordination of the observing programs of surveys across the oceans because they the solar observatories of the world, and are too wide: There are not islands through more detailed, speedy and mean- enough to use as stepping stones, nor has ingful compilation of observations by co- it been possible to connect the separate ordinated reduction with workers in the networks of longitudes and latitudes with relevant fields of geophysics. each other more accurately than 200 or Solar activity-solar flares, coronal and 300 feet, and the location of some islands chromospheric activity, and sun spots- is uncertain by a mile. The moon, how- will be observed as part of the overall ever, can be used as a stepping stone geophysical program. In particular, solar across oceans, using a new photographic flares will be studied in order to correlate technique that makes it possible to ob- them with changes in cosmic rays, iono- serve the moon with the necessary pre- spheric and auroral disturbances, and cision whenever it can be seen at night. meteorological phenomena. One of the This makes it possible to accomplish as immediate uses to which flare data will be much in a single year as could be done in put during the IGY has to do with the a century by the older methods, provided “Warning Service” program (see below ) . a sufficient number of observatories, well While regularly planned measurements distributed geographically, are included will go on during the IGY, it is especially in the program. The observational tech- important that experiments be conducted nique consists of direct photography of simultaneously throughout the world the moon, the camera being specially de- during periods of unusual activity of the vised to hold the image of the moon sta- sun. The Warning Service will collect tionary among the stars while the expo- data from all fields, as well as solar ac- sure is being made. The probable error tivity, and will broadcast the imminence, of a single observation is about 0.15 sec- onset or presence of unusual geophysical ond of arc, corresponding in general to effeets, such as solar flares, magnetic about 900 feet on the earth. Thus, 200 storms, ionospheric fadeouts and black- observations at each of 2 stations should outs, signaling the observers to proceed give the distance between them with a with their special preestablished study probable error of about 90 feet. The new Programrr. technique adds greatly to the precision FOURTE AFCNUAL RE’kOBT ‘1%

,&h which changes in the qxed of mta- changes precede and control tho8e id the 6011 of the earth can be measured, and ,’ or whether both the observational material obtained for these are controlled by upper atmospheric &is geodetic program may be expected to conditions (perhaps brought about by &ed new light on the inner constitution change5 in solar radiation). The world of the earth. line which the United States is most interested in is the 80th , west METEOROLOt3Y of Greenwich passing through the eastern portions of do rth America and the west The atmosphere is the working fluid of coast of South America, making use of an enormous engine which pick5 up heat existing stations in the Northern Hemi- in the tropics and discharges it in the polar sphere. The northern terminus of this In the course of this complex regions. line is Eureka, N. W. T. at 80” N., thermodynamic process, the atmosphere completely equipped with weather instru- Measure- creates winds and weather. ments and sounding balloons. The line ments of temperatures, pressures, humidi- then passes through the joint Canadian- ties, and winds from the few hundred such United States operated Arctic weather stations in the Northern Hemisphere are stations in the Canadian Archipelago and assembled into a picture of the current the Canadian stations in the state of the atmosphere, and are used to area, entering the United States at Buf- explain the existing weather pattern5 and falo. It hops along a series of United to predict their changes. In spite of the States stations, crosses over to station5 in large increase in number of these sound- the Caribbean, and reaches the Pacific ing-balloon observations in recent decader, Ocean at Balboa. There the presently there exist vast volumes of the atmosphere existing line comes ta an end, well north still unexplored. The relatively known of the equator. portion of the atmosphere is largely lim- It is proposed to extend this line to the ited to the lower reaches of the atmosphere by establishing eight addi- in the Northern Hemisphere: The air tional weather stations-the minimum maSse5of the and of needed for scientific analysis. Five of the whole upper atmosphere remain these stations would be located along the largely unknown. No marked advance in west coast of South America and the re- meteorology appears likely without a ma- maining 3 in . The only jor international cooperative effort in this presently existing station of this kind in field and the related fields of geophysics. South America, Port Stanley (Falkland The proposed United States program in Islands), would be incorporated in the meteorology will provide significant data line. in three areas: The lower atmosphere in Four of the proposed five new stations the Northern Hemisphere, where there for South America would be located at exist a number of stations in norcal opera- sites already recommended for weather- tion ; the Southern Hemisphere where aviation purposes by the International strategic, temporary new stations are pro- Civil Aeronautics Organization (ICAO) posed in order to understand this largely and endorsed by the World Meteorological unknown region ; and the upper atmos- Organization ( WMO). These four sta- phere from which data will be obtained in tions are Guayaquil, ; Lima, the rocket-exploration program. ; Santiago, ; and San Carlo5 de The North and South Poles will be Barilcche, Argentina. It is proposed that connected with a line of weather stations the United State5 furnish the technical equipped with sounding balloons capable guidance and specialized weather equip- of going to heights of 100,000 feet or ment, and that the respective South more. Station5 are to be established along American countries furnish the 16 ob- three pole-to-pole world lines. The data servers necessary tu man the 4 statiom obtained thereby should provide clues as The fifth South American station would to whether southern hemispheric weather be located at the Smithsonian Institution . 126 NATIONAL 6C~CE FOUNDATION rolq rtation at Montemma, Chile. Exht- OCEANOWAPHY AND OLACSOLOOY ing facilities and part-time assistance by Water in one form 05 another covcr5 resident observers tha would be used to some four-fifths of the earth’s surface. reduce the cust of maintaining this iifth Of the earth’s 197 million square miles of station. surface, the oceans account for some 147 In Antarctica, three stations would be millions; ice sheets, ice caps, and glacier5 *utablished: At Little America, at a point account for another 10 million or 5o. The near 80° S., 120” W., and at the South oceans are auperfZally well known as Pole, These &ions would complete the avenues of travel and commerce and as pole-to-pole line. The Little America reservoirs of food and dissolved minerals. rtation would also permit comparison Glacier5 are less well known-largely and with meteorological ob5ervation5 made by simply a5 ice masses associated with high previou5 expeditions. mountain ranges. Yet these two major The data from this line of station5 will features of our earth-surface environment be used in the study of various transport play a critical part in man’s existence and problems, e. g., heat, momentum, energy, being. Both oceanography and glaciology and water vapor. Equally important uses are linked to atmospheric events. The re- will be the determination of the location, lationship between these fields and strength, and movement of the various meteorology and solar activity is particu- jet streams, the study of the possible inter- larly close. Oceanography is intimately dependence of circulations of both hemi- related to weather, and there is an inter- spheres, and the addition of the Southern play between atmospheric and oceanic Hemisphere circulation to our knowledge. temperatures and water content. Glaciol- The Antarctic observations will also shed ogy is closely related to climatology-the further light on the reported differences longer-range changes in weather. Both in the wintertime structure of the upper are tied together in their roles a5 de- troposphere and of the lower stratosphere positories of the global water budget. between the Arctic and Antarctic regions, Oceanography.-As in the other fields leading to a better understanding of the of geophysics, the study of oceanography general circulation of the atmosphere., requires the conduct of many experiments The proposed Antarctic station near and the taking of many measurements if 80” S., 120” W., which introduces a major problems are to be solved. These slight “dog-leg” in the pole-to-pole line of problems have to do with the nature of stations, is chosen to permit the study cf oceanic currents, temperature, composi- a phenomenon uncovered from weather tion and levels, and total water content. observations made by the Ross Expedition A major problem is the study of the an- nearly 50 years ago. Study of these ret-fi nual cycle in sea level and the global water ords revealed the existence of air pressure budget of the oceans. Although all avail- waves or “surges” spreading outward able tide gauge and temperature data have from the neighborhood of 80” S., 120” W. been studied, the problem remains un- Since the atmosphere over Antartica is soived-because a minimum of 20 years known to be the coldest in the world, both of tide observations at a station are re- winter and summer, and also has in it5 quired to give a meaningful average, 50 Ross Sea area the most persistent low at- that values in one area can be compared mospheric pressure belt found anywhere, with values in another area taken at a it is possible that the effect of Antartica different time. As much or more could be on world weather may be proportionately learned by synchronous measurements much greater than indicated by its size. The propored three stations in the Ant- during one specific year. Simultaneous arctic, particularly that at the supposed measurements of fluctuations in sea level point of origin of the waves, plus the are probably the most tiective and the Antarctic stations to be established by least expensive means of studying the other countries will provide the needed “weather” of the oceans-i. e., the fluctua- Antarctic meteorological data. tions in ocean currents with time. To be . FOtiTH ANNUAL REPORT 127 of value, these observations must extend ice will melt out of the in over vast ocean areas. the summer, making it navigable. In ad- In low latitudes the recorded seasonal dition, the warming cycle, if continued, changes in sea level are about what can may melt enough ice now tied up in gla- be inferred from observed changes in tem- :iers to add to the sea level sufficiently to perature of the superficial layers, indicat- tiect the lives of millions of people liv- ing a change in specific volume rather ing along low coastal lands. Whether than in mass. In high latitudes, there is this actually happens or not, the slow also a change in mass. If these changes :hange of climate has heady begun to are associated with changes in currents, ihow a change of storm paths and redis- the currents at mid-latitude may be essen- tribution of rainfall, rendering some areas tially confined to superficial layers, where- previously well-watered more arid and, in as at high latitudes they may *extend to turn, bringing water to arid regions. the very bottom and are therefore not The objectives of the United States measurable by present standard tech- 3laciological efforts in the IGY program niques. Moreover recorded sea level is ~villbe twofold : ( 1) To extend the studies lower by about one-half foot in the North- >f glaciers on a worldwide basis in con- ern Hemisphere in northern spring and in junction with similar efforts of other coun- the Southern Hemisphere in southern tries and (2) to coordinate the existing spring than in the respective fall seasons. observations of glaciers with the varied From present data it cannot be deter- worldwide efforts in other fields of geo- mined whether this involves flow of water physics in order to establish quantitative across the Equator or between the fringes and qualitative indications of long-term of the ocean basins (where nearly all tide climatic variations affecting the world as stations are located) and the central por- a whole. The plan includes: ( 1) As- tions (where observations are inadequate). sembly of all available data on the varia- Such problems are analogous in ocea- tions of glaciers ; (2 ) analysis of the data nography to those in the meteorologic pro- obtained to determine the extent to which gram involving measurements of air flow glacier variations are caused by climatic across a meridian and across the Equator. change ; (3) study of the hydrological Similarly, the solution requires synchro- economy of specific glaciers with respect nous global measurements, which include to meteorological factors; and (4) studies (a) observations and reduction of data to establish, correlate, and trace climatic from existing tide stations; (b) temporary trends of the past and to improve future tide gages or surge recorders at some 40 predictions by combining these findings stations with emphasis on islands and the with those of solar and atmospheric Southern Hemisphere, particularly the physics. Antarctic; and (c) weekly temperature Two major efforts are planned in the readings to depths of about 1,000 feet Northern Hemisphere: (a) Alaska. One offshore from as many tide gage stations study region will be concentrated in the as possible. In addition to these tide and vicinity of the American Geographical So- surge observations, a major study will be ciety’s Juneau Ice Field project. Because undertaken of the sub-Antarctic oceans. of the significance of data already collected The structure and dynamics of currents in the region, conduct of the study during and other oceanic phenomena of this the IGY will be unusually valuable. (b) region, which is little known but of great Greenland. Intensive glacial studier of importance in several fields of geophysics, portions of the Ice Cap and fringe area will be explored intensively. in Greenland will be undertaken in coop- GZacioZogy.--Glacier studies have giver eration with Danish scientists associated clear indications that we are now in a cycle with IGY. Two Antarctic studies arc of warming which began about 1900. 11 also planned: (a) Little America. The is estimated that if the indicated warming Ross Shelf is the largest sheet glacier of continues for another 25 to 50 years, the its type in the world and has been studied 128 NATIONAL SCIENCE FOUNDATION

in part by American expeditions of the are associated with disturbances on the past. Much quantitative information i sun. A solar flare may bc immediately still lacking, and considerably more car followed by a sudden ionospheric disturb- be supplied by this effort. Among the ance. The growth of active 5un5pot5 may major tasks will be the survey of the 400’ be followed within a few days by gee-’ mile front of this glacier feature for eati, magnetic storminess and violent auroral mates of quantitative changes. Maps ant displays. These displays, which occur in aerial photographs of this region are avail high latitudes of the Northern and South- able; and the IGY efforts, taking advan, ern Hemispheres, are frequently accom- tage of this prior work, should provide z panied by radio blackouts which may major indication of the rates of snow ac completely paralyze communications in cumulation and wastage over a large seg these regions. Isolated meteorological or ment of the continent. In addition, the other observing stations find that although Bay of Whales area provides a vast labora. they may use radar locally, weather and tory of glacial phenomena fundamental tc associated information cannot be trans- the understanding of glacial mechanics mitted to central coordinating sites. (b) Satellite stations. Descriptions o; This problem is one of immediate concern the glacial conditions and snow accumu to the United States, particularly since lation on the high polar plateau indicate the northern auroral zone lies more over ,that the South Pole station affords a than over any other unique opportunity to obtain glaciological continent. data not now known. A glacial team oj Radio blackouts affect radio contact not three observers will be stationed at thiz only in the Arctic but in substation. Similar work will be carried as well. Radio waves propagating be- out at the station at latitude 80” S., longi. tween any two points follow the great tude 120” W. Operation of three stations circle distance between these points. Be- will permit direct correlation with one an- cause of the location of centers of popu- other as well as with the IGY glacial lation in the Northern Hemisphere, most studies of other nations in the Antarctic, radio communication paths from points in the United States to Great Britain, Europe IONOSPHERICPHYSICS and Asia penetrate or come close to the The ionosphere is a region of rarified, auroral zone; these communication chan- ionized gas between 50 and 250 miles nels are also subjected to absorption and above the surface of the earth. Some- radio blackouts, and other communica- what as a mirror reflects light, the iono- tion paths must be sought. sphere reflects radio waves and thus makes Solar activity changes greatly during possible long-range radio communications, the 1 l-year sunspot cycle. During periods radio telephony, and radio navigation. Df sunspot minimum, the sun is quiet; the The analogy between the ionosphere and ionosphere is then relatively normal and a mirror holds roughly true only in terms 3adly disturbed radio conditions are rare. of this reflective property, for the iono- During the several years, however, when sphere is a complex, vast region of the unspot activity is high, communications atmosphere, fluctuating in height and ire often erratic over most regions of the depth, varying in its ionization, and im- globe. The period chosen for the IGY portantly affected by solar activity, geo- :oincides with a period of maximum solar magnetic disturbances, the aurora, and rctivity. perhaps by meteors and thunderstorms. Predicting the future state of the iono- A study of the ionosphere also inher- iphere is one of the major problems in ently involves a study of geomagnetism, onospheric physics. The prediction must the aurora, and solar activity. While the ndicate whether or not direct radio con- “normal” (i. e., closely predictable) iono- :act will be possible, the frequencies to be sphere is maintained by solar radiation, :mployed if the possibility is good, and the occurrences of disturbed ionic layers he alternative “radio routes” and fre- FOURTH ANNUAL REPORT 129 quencies if the probability for direct con- tions, involving Arctic and Antarctic rc~ tact is low. With regard to the Arctic, gions as well as central zones in the the problems are many and complex, and Northern and Southern Hemisphm: it is equally possible to have a failure in ( 1) A series of vertical incidence sound- an ionospheric prediction as in a weather ings whereby the ionosphere is probed by forecast. Improvement in radio prog- radar pulses, (2) a series of scatter sound- nostication requires, among other things, ings whereby broad areas of the ionosphen additional observing stations in the Arctic are swept by radio energy of fixed and regions, not only for the ionosphere but multiple frequencies, and (3) some studies also for geomagnetism and for the aurora. of basic properties of the ionosphere layers An intensive coordinated study and ob- having to do with the mechanical and servational program in each of these fields atomic dynamics of the ionospheric is required. A study of the ionosphere atmosphere. can scarcely be undertaken from observa- Vertical soundings.-Vertical sounding tions made in only one nation or in one measurements of the ionosphere provide portion of the world. A national network data on the vertical height of the iono- is insufficient for the prediction of condi- sphere layers and on the critical radio tions either over extensive geographic frequencies. Because the ionosphere var- areas or over extended time periods. ies in space and in time, information is While attempts at extrapolation may be needed over the surface of the earth, made over the “silent areas,” the ac- taken regularly throughout the day and curacies are quite low. night. Automatic ionospheric instruments While meteorological observations at a are used to probe the ionosphere at fre- single site are confined to the weather quent intervals, using radar techniques. parameters in the general vicinity of the The radar pulses are transmitted vertically station, new techniques in ionospheric up and their reflections are picked up by observations make it possible to gain in- the same device, which measures the formation about the ionosphere thousands round-trip transit time and thus permits of miles away. . This is accomplished by the determination of the distance to the oblique-incidence, back-scatter probings, ionosphere. which in one form of the experiment can These data from many stations over the be rotated in azimuth so as to provide in- earth are needed for an understanding of formation in 1 or 2 circular zones whose the ionosphere as a whole, for insight radii may be about 600 and 1,200 miles, into the behavior of radio waves over the respectively. This new technique greatly frequency range from 1 megacycle to 25 increases the flexibility of the observa- megacycles, and for use in the prediction tional network, but a clear interpretation of frequencies that can be used in long- of the results stillwquires extensive com- range radio communications. At the pres- parison with the usual type of vertical ent time, reasonably adequate coverage is incidence probings. The latter observa- available in the United States through tions provide ionospheric information only its chain of stations, while excellent cover- in the immediate locale of the station. age is available in , which prcG The use of the oblique-incidence stations portionately, has a denser network of sta- Capitalizes on this new observational tions. Major gaps of interest to the technique and will contribute to improve- United States exist in the Arctic, South ments in ionospheric predictions. More America, Antarctic, and North Atlantic; intensive study, especially of the Arctic gaps in other parts of the world, of most atmosphere (by ionospheric, auroral, and direct interest to other nations, will be geomagnetic observations), will provide covered by the latter; and the combined a new dimension for the improvement of data will be invaluable in advancing basic radio forecasts. ionospheric knowledge and improving The ionospheric physics program con- radio communications. The United States sists of three principal sets of investiga- program in vertical soundings consists of l80 NATIONAL SCIENCE FOUNDATION

four park: (1) Arctic and South bombarding particles, but aho provide UI America, (2) Antarctic, (3) North At- with the knowledge needed to predict the lantic, and (4) Data Quality Control. amount and kind of disruption of radio Seattsr soundings.-Vertical 8oundings communications, how best to circumvent provide 8pecific data on ionospheric height it, or actually how to utilize the aurora in the limited region immediately over the a8 a means of propagating radio waves. 8tation. Ideally, to map the ionosphere The disruption of radio communications adequately would require a dense net- is felt mostly in the Arctic and sub-Arctic work-literally thousands in the United region8 and corresponding area8 in the States alone a8 against the present four. Southern Hemisphere. Yet it ir in these To provide data over large regions, scatter frozen and desolate region8 that the main- sounding is used giving oblique incidence tenance of satisfactory radio communica- data over a large area ab the antenna is tions is even more important than almost rotated, actually or in effect to scan the anywhere else-in term8 both of commu- ionosphere. Two types of scatter sound- nications and of safety. ing studiea are needed: Fixed frequency The ionized sheet8 and ray8 directly and multifrequency. associated with the visible aurora are di- Ionospheric dynamics.-More data are rectly responsible for many of the anoma- needed on the specific properties of the lous effect8 observed in radio propagation. ionosphere a8 well a8 on it8 overall be- For example, the density of ionization havior a8 a whole. The behavior of mole- gets so large that very high frequency cules and electrons in the ionosphere-in radio waves may be picked up at distance8 particular, molecular and electron colli- far beyond expectation. Thus one radio rions and motions-can reveal the radio- station may provide unwanted interfer- wave absorption properties and tempera- ences to another distant one during an ture of the ionospheric layers. In addi- aurora1 display. But more important, at tion to individual particle motions, there present, are the interfering effects on radio are motion8 of patches of ionized particles. waves which cause melFsagesto be unin- These motion8 constitute ionospheric telligible, or the absorption of radio waves winds, whose dynamic8 need to be ex- which may be 80 great that no message get8 plored for basic and applied reasons. Two through at all. The path8 of the charged investigations are to be undertaken in this particle8 in the atmosphere may be traced i ,’ area: (1) I onospheric winds and (2) through observation of aurora. Spectro- a * cro8s modulation experiment8 scopic and photometric analyses of aurora show us not only the composition of the ,I; AURORAAND AIROLOW atmosphere at this level but also the tem- 1 perature of that portion of the atmosphere v The bombardment of the earth’8 atmos- ? phere by electrically charged particles and the energies of the bombarding particles. produces four major effects. One effect The North American Continent is an is characterized by very high speed par- area ideally situated to study the aurora ticles which produce cosmic rays. The ./ since it is possible to have access acros8 other three come from relatively low speed i the aurora1 zone and far to the north of F particles. Their manifestations are : (a) i it on continental land masses. There are / Magnetic storms, (b) ionospheric storms, already a number of stations in North and (c) the aurora, which is the luminous America working on aurora1 and airglow I trace of the charged particle8 in the atmos- problem8 that could be integrated with a phere. All three of these phenomena give few new stations into a very efficient net- UJ an insight into the effects of the bom- work to investigate these problems. In j bardment of the atmosphere by charged general, the network required for this

3 particlea. Comprehensive studies of these phase of the program will fit well into P rubjects not only tell us the nature of the stations required for other phases of the I upper atmosphere and the action of the IGY programs. The establishment of a

j r;

i: d FOURTH ANNUAI, REPORT 131

main base and two satellite bases on the netic field developed by the8e sheet cur- Antarctic continent will be a major step rent8 with the normal geomagnetic field toward the establishment of a reasonably produce8 the innumerable variation8 80 8+8factory network of stations in the pronounced at high latitudes. In addi- Southern Hemisphere. Two of the likely tion to current8 flowing around portion8 stations in the southern zone network are of the earth within ionic layers, a current of particular intereat. The first is Mac- is hypothesized which flows around the Quarie Island, between Australia and earth at a distance of about 20,000 miles. Antarctica, which is on the same geomag- The magnetic field of this ring current also netic field line a8 College, Alaska. A affects the local field and introduces fur- second is a point within a few hundred ther transients which also cause varia- kilometer8 of Little America that is paired tions in the geomagnetic field. Because similarly with Chesterfield, Baker Lake, of these effects, geomagnetic record8 dis- Canada. The establishment of aurora1 play complex fluctuations whose nature observations at both pair8 of stations is is incompletely understood. essential. Changes in the earth’s magnetic field The program, requiring an orderly and are closely linked to ionospheric and au- well placed network of cooperating sta- roral displays. A geomagnetic storm fre- tions, is concerned with large-scale air- quently occurs simultaneously with a glow and aurora1 phenomena. In this strong aurora and a radio blackout. To field there are four main problem8 : ( 1) gain better insight into the physical mech- Airglow latitude intensity profile, (2) anism which causes both the geomagnetic aurora latitude spectrum and frequency storminess and the ionospheric disturb- profile, (3) aurora1 longitude spectrum, ances, it is essential to obtain more infor- frequency, and continuity profile, and mation on the interdependence between (4) Northern-Southern Hemisphere corre- the two. More geomagnetic data must be lations. The program has 5 major as- collected, particularly at the higher lati- pects: Visual and special observations, tudes. In addition to its correlation with radar-type observations, spectrographic radio blackout8 in the auroral zone, the patrol, photometric observations, and geomagnetic field portray8 constant ir- data reduction8 and analysis. regular fluctuations. Some thought ha8 been given to the possibility that at least OEOMAONETISM some of these rapid fluctuations are Geomagetism ha8 various important caused by the penetration of meteors through the atmosphere. relation8 and implications cutting across almost all areas of study in the physic8 The primary objective of the geomag- netic program during IGY is to shed new of the atmosphere. In addition to its own light on the conditions responsible for specific uses in surveying, navigation (in- magnetic storms and other little-under- cluding missile guidance), and exploration stood transient effects. Almost all fea- for mineral8 and petroleum, geomagnet- tures of the proposed program are directed ism ha8 broad and basic implications in ta this end, the minor exception8 being the study of the ionosphere, radio wave (1) exploratory rocket observation8 at propagation, aurora, cosmic rays, a8 well great heights, (2) a station at Jarvis Island as other fields of science. to shed light on certain unexplained effect8 While the main portion of the earth’8 of possibly great importance in equatorial geomagnetic field originate8 in the solid regions, and (3) exploration of the prac- core of the earth, practically all the fluc- tically unknown field of high-frequency tuations and variations of the field origi- magnetic fluctuations. The proposed in- nate in electric current8 which flow in the vestigations bear upon the fundamental atmosphere. These current JystemJ flow problem8 of atmospheric physics. within the altitude range 50-240 miles, Two new temporary observatories will with especilly strong current over the be established in Alaska at Big Delta and polar caps. The interaction of the mag- McKinley Park, which together with the 132 NATIONAL SCIENCEFOUNDATION existing observatory at College will form activity, and the earth’s magnetic &Id and a tripartite array for the recording of magnetic storms also afkct mmnic rays. unique data bearing on the electric cur- The magnetic field of the earth is the rents characterirtic of the north polar chief instrument for analyzing the energy aurora1 zone. Two outpost station8 will of cosmic rays. The cosmic rays arc bent be established a few miles from the College in this field in such a way that the low- observatory for the recording and analysis energy ray8 cannot arrive at equatorial of magnetic field gradients at time8 of latitude8 but tend to come in. chiefly near magnetic disturbance. Special rapid-run the magnetic pole8 ; the highcnergy com- equipment will be installed and operated ponents arrive at all latitudes. To study at seven observatories. Two magnetic the high-energy portion, observations are observatories will be established and oper- made near the equator. To study the low- ated at Little America and at the impor- energy portion, observations should be tant, and unique South Pole site. A semi- made in the Arctic and Antarctic regions. automatic magnetic observatory at Jarvis The connection8 between 8olar effect8 and Island in the Pacific will be established cosmic ray8 are generally moat conepicuous and operated for the study of daily mag- for the low-energy cosmic rays; thus ob- netic changes peculiar to the equatorial servations in the Far North and Far region. Jarvis Island is near the junction South may unravel the fundamental facts of the magnetic and geographic . of the origin of cosmic rays. Another Special apparatua will be installed at four cosmic-ray phenomenon is the large de- high latitude observatories, including Col- crease in cosmic radiation often associated lege, for the 8tudy of magnetic oscillation8 with magnetic storms. It appear8 that in the range of l-10,000 cycles per second, these storms alter the magnetic conditions and visible-type magnetic recorder8 will be in the vicinity of the earth, and that these installed at six sites of ionospheric and changed condition8 may either deflect or auroral observations. decelerate cosmic radiation. This means that cosmic ray8 represent a powerful tool COSMIC RAYS with which to study magnetic phenomena The existence of cosmic rays has been many thousands of miles from the earth. known for 50 years, but our knowledge of Perhaps the most spectacular phenom- them is elementary. The problem is one ena observed in cosmic radiations have of major importance in understanding our been the rapid and very large increases universe, involved a8 it is in both astro- which sometime8 occur simultaneously physics and in understanding the structure with eruptions of gas on the solar disc. of the atomic nucleus. Implications of These coincide with disturbances in the the latter are highly practical matters, for ionosphere, which may be so severe a8 to cosmic ray energies are literally millions black out radio communications. Such of times greater than the energies which violent solar flares are generally followed the largest atomic accelerators can pro- by magnetic storms, which can be observed duce. by violent changes in the earth’s magnetic Cosmic ray8 are known to consist of field and which can adversely affect com- streams of electrically charged particles- munication circuits. Detailed knowledge mostly protons (the positive particles of of cosmic rays requires simultaneous in- atomic nuclei) but also the atomic nuclei vestigations of flares, sun spots, and chro- of heavy elements. These particles bom- mospheric eruptions. bard the earth all the time, and they come The question of the origin of cosmic from every direction. Their origin ap- rays remains the outstanding basic prob- pears to be interstellar space, but whether lem in this field. The particles are re- the source is the sun, the stara, or some lated to solar phenomena-in particular, phenomenon or process of interstellar to the large increase8 of radiation accom- apace is unknown. There are clear con- panying some solar outbreaks. Perhaps nections between cosmic rays and solar conditions at the surface of the sun and FOURTH ANN?JAIi REPORT 133 in the outer solar atmosphere may be such dy direct data in sdar studiu, mete- a8 to accelerate nuclear particles to cosmic urology, and cosmic rayr have been rc- my energies. In other word8, the sun btricted to the lower atmosphere. may well behave like a giant cyclotron, The development of rocket8 during and vastly more powerful than any man-made after World War II has provided a method reactor. The principles that nature u~lcs of penetrating many time8 higher into the in such an accelerator are unknown; the atmosphere. Rockoow, balloon-borne study of the‘origin of co8mic rays may give unall rocket8 that are fired once the bal- us the answer. Most’ of the basic dis- loon ha8 reached it8 maximum altitude, coveries of the short-lived meson8 and have a range of 60 miles. Aerobees or other energy particles have come from ground-launched rockets, have a range of studies of cosmic radiation. Such studies 144 miles. Somewhat comparable rock- have blazed the trail in our understanding ets have been developed by other nation8 of nuclear forces, furnishing the impetus and are to be used for similar purposes in to the construction of large accelerators the IGY program. which are now being used for more de- Both types of measurement, direct and tailed investigations in this low-energy indirect, are needed. Conventional meas- range. urements, which can be made readily, The program call8 for investigations of inexpensively and extensively, provide the three problems: ( 1) Exploration of the large bodies of “indirect” data upon which variations in mass and energy of primary ultimate solution8 of major geophysical co8mic radiation, (2) exploration of the problem8 depend. Rocket measurements, variations in cosmic radiation with both which are relatively costly and difficult, altitude and latitude, and (3) investiga- provide intensive sets of “direct” data for tions of the long-time fluctuations in the a short period of time, and this informa- neutron component of cosmic rays. These tion can be used ta “calibrate” indirect studies require simultaneous measurement8 data. This, in effect, permits the con- widely made over the earth, including the version of large bodies of indirect data Arctic and Antarctic region8 a8 well as the into direct data. At the same time, new temperate and equatorial zones; they also discoveries are possible by rocket tech- require parallel studies of solar activity, niques. geomagnetism, aurora, and ionospheric Some of the types of reaulta attained physic8 in view of the complex interrela- by rocket explorations are the following: tionships of events in these fields. ( 1) Solar radiation of the shorter wave lengths, which are absorbed in the upper ROCKETEXPLORATION OF THE UPPER atmosphere and hence never reach the ATMOSPHERE earth, has been successfully studied-for example, a rocket measurement led to the One of the principal problem8 in the discovery of X-rays in one of the iono- investigation of atmospheric phenomena spheric layers. (2) Solar ultraviolet light has been the general difficulty of obtain- measurements from rocket8 have estab- ing direct measurements. Until relatively lished the variation of the ozone with recent years the maximum height attain- heights up to an altitude of 42 miles. able by sounding balloon8 has been some (3) Electric charge densities in the iono- 10 to 15 miles; within the last few yearr sphere and collision frequencies of the air this range has increased to about 24 particles have been meaeured directly. miles. Studies in meteorology and cosmic (4) What are believed to be auroral par- rays have made extensive use of such bal- ticles have been detected in rocket-borne loons. However, the upper atmosphere Geiger counters. ha8 not been open to direct observation The program calls for the launching by these techniques, which has meant that of 37 rockoons and 36 Aerobees from sites no direct data have been available in in New Mexico, Greenland, Canada, and auroral or ionospheric physics, and the Alaska. United States firings will be co- 134 NATION& SCIENCE FOUNDATION ordinated with those of other nations, ultraviolet light and X-rays; auroral par- particularly at those crucial time8 of un- ticles ; ozone distribution; ionospheric usual solar activity. Each rocket will charge densi tie8 ; and cosmic radiation. carry instrumentation within the very The results of these investigations will be severe weight limitations, to measure sev- integrated with the results of simultane- eral quantities : atmospheric pres8ure, ous measurements made in each of the temperature and density; the earth’8 mag- major field8 of geophysics that represent netic field, especially during aurora1 dis- aspects of or directly involve the atmos- plays; night and day airglow; rolar and phere.