The international geophysical year 1957-58 and ... - ACS Publications

Ionosphere (MCI), (b) International Union for Scien- tific Radio (URSI), (c) the International Astronomical. Union (IAU), and (d) the International Un...
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THE INTERNATIONAL GEOPHYSICAL YEAR 1957-58 AND CHEMISTRY LEWIS E. MILLER Geophysics Research Directorate, Air Force Cambridge Research Center, Air Research and Development Command, L. G. Hanscom Field, Bedford, Massachusetts

Tm planning for the International Geophysical Year (IGY) 1957-58 has heen in operation since April, 1950 ( 1 ) . The present IGY is a lineal successor of the International Polar Years 1882-83 and 1932-33. The ICY of 1957-58 originated from the suggestion of Dr. L. V. Berkner before a small group of geophysicists meeting a t the former home of Dr. J. A. Van Allen, Silver Springs, Maryland. The proposal was formally hrought before the International Council of Scientific Unions (ICSU) through the recommendations of four international scientific bodies, (a) The Mixed Commission on the Ionosphere (MCI), (b) International Union for Scientific Radio (URSI), (c) the International Astronomical Union (IAU), and (d) the International Union of Geodesy and Geophysics (UGGI). After the decision that a third Polar Year should he organized, the International Council of Scientific Unions wisely midened the scope to cover the entire globe and designated it the International Geophysical Year. World-wide puhlicity has been given to this extensive international enterprise. The worcis, "International Geophysical Pear" and "Operation Deepfreeze," are heard almost daily over the radio. I t is the purpose of this paper to present a brief account of the IGY program, particularly those portions of interest to chemists. Although the fields of science which are cooperating are principally those related to geophysical phenomena, there are many phases of the plans in which chemistry is involved either directly or indirectly. HISTORICAL

The first International Polar Year 1882-83 originated through the efforts of Lieutenant Karl Weyprecht, a well-known Austro-Hungarian polar explorer. After returning from his polar expedition of 1874, Weyprecht suggested a t the 48th Meet,ing of the Association of German naturalists and physicists on September 18, 1875, a t Gratz, Germany, that instead of isolated voyages into the polar regions, expeditions should he organized on an international basis and should have for their primary objectives t,o make simultaneous physical ohservations a t several different points about the Piorth Pole. Previously polar voyages had been made principally for geographic discovery, while scientific investigations were considered of minor and of secondary importance. Briefly the plans were to send out small expeditions whose tasks would be to conduct strictly simultaneous

ohservations with like iustruments and. following like instructions. Weyprecht who did not live to see his dreams mat,erializecommunicated his proposition to his noble friend, Count Hans Wilczek, and wrote to Australia, Brazil: Germany, Denmark, France, Holland, Russia, Sweden, and the United States. He succeeded in obtaining active cooperation from interested scholars and government support in all the countries. In 1877-78 the Russian-Turkish War temporarily delayed the preparations. After three International Polar Conferences (the first, October 1-5, 1879, in Hamburg; the second, August 7, 1880, in B e n ; and the third a t St. Petershurg, August 1, 1881) the First International Polar Year became a reality. Nine countries set up 12 arctic and 2 antarctic stations, while 14 countries took part in 34 permanent stations. The United States occupied sites at Point Barrow, Alaska and Fort Conger, Lady Franklin Bay. Interesting accounts of these explorations and investigations are given in Science (9) and Nature (8). The observations of phenomena relating to meteorology and terrestrial magnetism were given top priority. In addition there were investigations on the aurorae and ast.ronomical phenomena. It may be stated that enough data were secured during this first cooperative enterprise t o provide a better understanding of the earth's magnetic field and of the distribution of the aurorae. Fifty years later the jubilee of the First Polar Year was organized. The stations for the Second International Polar Year 1932-33 corresponded with those of the First Polar Year as nearly as possible. During these intervening years (1882-1932) notable scientific and geographical discoveries had heen made. Both the north and south geographic poles had been reached, and t,he north and south magnetic poles were located. The ionosphere, a region in the upper atmosphere, was discovered. Weather balloons had been more highly developed. For example in 1932 Science Service reported that a stratosphere balloon ascent would aim for a 12-mile height, an altitude hitherto unknown. Although no outstanding achievementswere reported for the Second Polar Year, there was greater coordination of geophysical knowledge and a better understanding of mutual international organization for obtaining gew physical data. The information obtained during the Second Polar Year from ionospheric studies contributed greatly to advancement in the field of radio communication. JOURNAL OF CHEMICAL EDUCATION

THE ORGANIZATION OF THE IGY 1957-58

The International Council of Scientific Unions is the official sponsor of the International Geophysical Year 1957-58. The council appointed a special committee, CSAGI (ComitB Special de 1'AnnBe GBophysique Internationale (Special Committee for the International Geophysical Year)). The chairman of this international committee is Professor Sydney Chapman, new consultant a t the Geophysical Institute, College, Alaska, and formerly before his retirement professor of physics at Queen's College, Oxford, England. The purpose of this committee is to provide the central organization and to coordinate the activities of the participating nations. At the present time some 50 countries have indicated their willingness to participate in the IGY ahvities. Never before in the history of science have so many nations and scientists united in search for truth. All of the cooperating nations were invited to form their own national committees to organize their participation. In the United States the National Academy of SciencesXational Research Council is the parent organization. The Academy organized the U. S. Xational Committee for the International Geophysical Year (USNC-IGY) of which Dr. ,Joseph Kaplan, University of California, Los Angeles, is the chairman. The purpose of this committee is to direct and execute the U. S. IGY program. The U. S. National IGY Committee enlisted the aid of various scientists from uuiversities and research institutions. Formal Technical Panels have been formed in each of the geophysical fields, and together with subcommittees have been assisting in the technical direction of the U. S. program.

Figure 1.

The outline of the U. S. Organization for IGY is shown in Table 1. Other participating nations that have national academies of science have similar organizations. TABLE 1 The Organization of the IGY 1957-58 ICSU (Internstianal Council of Soientific Unions)

1

CSACI (ComitB Special de'lAnn6e Geophysique Internationale) NATIONAL ACADEMY SCIENCES!X~TIONAL RESEARCH COUNCIL I

USNGIGY (U. S. Kat,ional Committee for the International Geophysical Year) I

TECHNIC^ PANELS

(by scientific disciplines) ~OMMITPEES REOIONAL (Arctic, Antrarotio, Continental, Equetorial]

In order to obtain the necessary fiscal support,, t,he U. S. Nat,ional Committee made its request for funds to Congress t,hrough the Natioual Science Foundation. The ICY program in the United States will cost, including the Satellite project, the logist,ic support of the military departments, and university contributions, a sum variously estimated at from 200 million to 600 millioo dollars. I t should be emphasized that through the National Science Foundation Congress has appropriated directly only about 40 million dollars for the IGY program. The Department of Defense (the Air Force, Army, and Kavy) has agreed to cooperate and

The Chemistry and Geomorpholosv of the Upper Atrnosphoro

VOLUME 34, NO. 9, SEPTEMBER, 1957

V E R T I C A L DISTRIBUTION OF ATMOSPHERIC CONSTITUENTS

Fipun 2.

T h e ARDC Model Atm-phem

(9

The so-called "maleoular weizht" of air at high altitude* can be computed far cbtaining t h e real kinetic temperature aa a function of altitdde. The notation "number density-m-8." in&cated as n( ), denotes the number of molecules or atoms of the partioular stmospheric constituent present in a cubic centimeter at the temperature and pressure existing at any eorrewonding altitude.

assist in every way possible in keeping with it,s normal activities. Again it should be pointed out that United States government laboratories have for many years been conducting geophysical programs in cooperation mit,h several foreign countries and research inst,itutions of the United States. These normal cooperative programs are expected to continue and will utilize the dat,a provided by existing geophysical stations and networks. The IGY has provided the rare opportunity to establish new observation stations, to re-evaluate critically our current geophysical knowledge, and to exploit the potentialities of nelv scientific tools. THE PURPOSE AND SCOPE

Extensive scientific investigat,ions are planned for the International Geophysical Year 1957-58 (which began July 1 , 1957, and continues through December 31, 1958) for the purpose of formulating and testing theories on many geophysical problems. I t is difficult to find ally law and order to geophysical phenomena; t,he weather is as unpredictable as the occurrence of the aurora borealis, the magnetic field of the earth and its variations. The mere enumeration of the fields of geophysical disciplines to be investigated is evidence of the gigantic and comprehensive nature of the program. A partial list of the problems to be investigated is: The a.irglow and zodiacal light, the aurorae, cosmic rays, geomagnetism, glaciology, gravity, ionospheric physics, latitude and longitude, meterology, oceanography, rocket explorat,ion of the upper atmosphere, seismology, and solar activity. "World Days" on the average of five per month which will include some special world-wide "Alert Days" will be observed. From a network of observation stations scattered from the arctic to the antarctic regions scientists will make simultaneous observations. "Alerts" mill be observed for such geophysical phenomzena as magnetic and ionospheric storms, and aurom e which depend upon solar flares. These events cannot be predicted with certainty more than a few days prior to their occurrence. The National Bureau of Standards radio forecasting station a t Fort Belvoir, Virginia, has been designated the IGY World Warning Agency for issuing "Alerts."

India will have a network of eight cooperating stations. Kodiakanal will receive notices of "Alerts" and will transmit them by broadcast to New Delhi. ICodiakanal will also issue its own "Alerts." India has an excellent ionospheric laboratory (Institute of Radiophysics and Electronics) at the University of Calcutta. The following eight Indian stations will make observations: Delhi, Bombay, Madras, Tiruchirapally and Trivandram, Haringhatta, Ahmedabad, and Kodiakanal. It is expected that round-the-clock observations will be undertaken. The whole of the research facilities and personnel of the physics department, University College, Ibadan, Nigeria will cooperate. The college has set aside several thousand pounds for the IGY. The Nigerian College of Arts, Sciences and Technology, which has branches a t Zaria (Northern Nigeria) and Enugu (Eastern Province) as well as Ibadau, will participate. These few illustrations indicate the international cooperation which is most heartening in a time of worldwide dissensions. THE MORPHOLOGY O f THE UPPER ATMOSPHERE

A review of the main features of the morphology of the earth's atmosphere is shown in Figure 1. Note that there are several changes in the present day conception of upper atmospheric properties since the publication of a similar chart in 1954 (4). The regions of the atmosphere are better defined, e.g., the ionosphere (a special region) is now considered to be a continuous region of distribution of electrons instead of occurring in layers as formerly believed. More information has been obtained upon atmospheric composition, pressure, density, and temperature. There is evidence that the gravitational separation of atmospheric components as found by Paneth and reported in the above reference to begin a t about 70 kilometers is doubtful, except in an atmosphere in the absence of winds and other movements in the upper atmosphere. Complete mixing is now assumed up to 180 kilometers, or probably higher altitudes, from rocket experiments. From the use of known atmospheric densities, and molecular oxygen concentrations from rocket experiments which are fairly reliable up to about 130 to 140 JOURNAL OF CHEMICAL EDUCATION

Figure 3. The Spaculstive ARDC Model Atmosphere to High Altitvdos (5)

his indicates that even at extreme altitudes the earth's atmosphere is esseotially an oxygennitrogen atmosphere, the arysen and nitrogen being in their atomic states.

LOG NUMBER

kilometers, it is possible through c~rtainr2asonable assumptions to determine the vertical distribution of the atmospheric constituents (5). These distributions are shown in Figures 2 and 3.'

TABLE 2 Components of the Airglows

The mysterious upper atmospheric phenomenon known as the airglow is global. On a clear moonless night if all the stars were removed the night light would he diminished only about one seventh which hardly would be noticed. The airglow is enhanced at twilight. There is a diurnal and seasonal intensity variation. There are also irregular variations, or "patchiness," over the sky which vary during the night. The generally accepted theory is that it results from photochemical reactions occurring in the upper atmosphere caused by absorption of solar energy during the day and slowly emitted during the night. The strong components of the air gloy are the green and red oxygen lines (5577A and 6300 A); the sodium doublet D line (5893 A); the OH bands of the hvdroxvl molecule in the infrared; 1 The notation, LOG NUMBER DENLYITY-CM-~, is employed to denote the logarithm of the number of molecules or atoms of the particular atmospheric constituent present in a cubic centimeter at the temperature and pressure existing at any corresponding altitude. The use of the term, number density, in upper atmospheric research may he understood through the following relationships. The mass density, p, is defined by

in which n is the total number density, i.e., the number of particles present in one cubic centimeter; and m is the mean mass of an average air particle. The general gas equation is (2)

whew k and ' l ' h m t r , rrspertivrl~,the l%oltzrnannv o m t ~ u 3rd t d e w I i l v i . The iuwlsmrvrnl rquntion nbtinp, the prrsPWV, I ) . :wd the den~it\.,P , at 3ny ?Ititud~, ;, i* ~ i w I>\. n -dp

=

pgdz

(3)

where p is the density of the gas, g is the acceleration of gravity, and the minus sign is used since the pressure of the emth's atmosphere decreases with increasing altitude, z. Equation (3) is the familiar hydrostatic or barometrio formula. For an ideal gas

VOLUME 34, NO. 9, SEPTEMBER, 1957

CM-'

and possibly nitrogen bands (Table 2). The height, vertical distribution, distribution of intensity are among the synopt,ic studies to be undertaken.

THE AIRGLOW AND AURORA

p = nkT

DENSITY-

Comfit-

Svs1e.s

wnl

----

I'ran9ilion

[OI] 1011 ~a 0% 0,

Green line, 5577 A IS ID Red lines. 6300.6364 ID aP D lines, 5893 8; *P 2S Herzberg bands A%: X34 Kanlan-Meinel atmos- biz.' Xaz;

OH

8645 A Meinel hmds

x

Enerw ev.

4.17 1.96 2.10 4.47 1.63

Vibration23.25, rotation