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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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Suggested Citation:"Special Research Program." National Research Council. 1965. Report on the U.S. Program for the International Geophysical Year: July 1, 1957 - December 31, 1958. Washington, DC: The National Academies Press. doi: 10.17226/26118.
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X V I I I SPECIAL RESEARCH PROGRAM S p e c i a l Research

SPECIAL RESEARCH PROGRAM Page A. Organization of Committee on S p e c i a l Research Grants 815 B. Summary of Committee Act i o n s 815 C. P r o j e c t O b j e c t i v e s and R e s u l t s 815 50.1 I n v e s t i g a t i o n s of S o l a r - T e r r e s t r i a l Problems 816 50.2 P r e l i m i n a r y A n a l y s i s of IGY Magnetic R e s u l t s from Alaska Observatories 818 50.3 IGY P i l o t Studies 819 50.4 Research on IGY Airglow, Ionosphere & S o l a r A c t i v i t y Data 821 50.5 Research on Problems of the S o l a r Atmosphere, Magnetic Storms and Cosmic Rays 822 50.6 Studies i n Ionospheric P h y s i c s and Airglow 823 50.7 Studies of E a r t h ' s G r a v i t y 824 50.8 Studies of A n t a r c t i c I c e S t r a t i g r a p h y 825 50.9 Geomagnetic I n v e s t i g a t i o n s of IGY Data 827 50.10 A n a l y s i s of IGY Seismic Data 828 50.11 Studies Based on Sea and E a r t h Tide Data 830 50.12 I n v e s t i g a t i o n s of S o l a r Radio Emissions 832 50.13 G l a c i o l o g i c a l Studies a t Wilkes S t a t i o n , Budd Coast, A n t a r c t i c a . . . 833 814

X V I I I . SPECIAL RESEARCH PROGRAM A. Organization of Committee on Special Research Grants 1. Establishment of Committee. As the IGY program got i n t o operation, the e a r l y r e - s u l t s made i t clear t h a t r a p i d analysis of data might prove useful i n guiding the course of observations, and might t u r n up unexpected r e l a t i o n s h i p s t h a t could be covered i n the observing program. The USNC was able to e n l i s t the assistance of the Ford Founda- tion,and then established a committee t o review suggestions f o r immediate data analysis. 2. Composition o f the Committee. ( A f f i l i a t i o n a t time of appointment.) a. Committee Members Joseph Kaplan Hugh Odishaw F.W. Reichelderfer A.H. Shapley, Chairman M.A. Tuve Uni v e r s i t y of C a l i f o r n i a National Academy of Sciences U.S. Weather Bureau Central Radio Propagation Lab., NBS Dept. T e r r e s t r i a l Magnetism, Carnegie I n s t i t u t i o n of Washington b. Secr e t a r i a t (IGY S t a f f ) . S. Ruttenberg ( t o June 1964) P.J. Hart (from June 1964) 3. Committee Meetings. There were two meetings of the committee. F i r s t Meeting Second Meeting January 20, 1958 June 20, 1960 Washington, D.C. Washington, D.C. Some of the review work was conducted by correspondence. B. Summary of Committee Actions U n s o l i c i t e d proposals were received by the committee i n q u i r i n g about the a v a i l a - b i l i t y of fimds f o r data an a l y s i s ; i n a d d i t i o n , several other areas i n which data ana- l y s i s might prove useful were in v e s t i g a t e d by the committee. I n reviewing proposals, i t was recognized a t the outset t h a t prompt funding of i n t e r d i s c i p l i n a r y studies would be most promising. A f t e r the f i r s t few pr o j e c t s had been i n i t i a t e d , the USNC, working w i t h the National Science Foundation, was able to secure federal funds f o r i n t e r d i s c i p - l i n a r y research. The committee therefore decided t h a t the remaining Ford Foundation funds should be used f o r worthwhile p r o j e c t s t h a t might be d i f f i c u l t , f o r any reason, to fund through normal government channels, or f o r programs whose objectives could not be defined r i g o r o u s l y but whose p r i n c i p a l i n v e s t i g a t o r was s u f f i c i e n t l y reputable as to be considered a good r i s k f o r a modest p r o j e c t . I n t h i s way, the committee was able to b r i n g to the United States several well-respected s c i e n t i s t s from abroad to work a t U.S. i n s t i t u t i o n s on analysis of IGY data, thus not only c o n t r i b u t i n g to the output of the IGY but enhancing cooperation between s c i e n t i s t s i n t h i s country and t h e i r c o l l e a - gues abroad, C. Project Objectives and Results The objectives and r e s u l t s of the Special Research p r o j e c t s are described i n the f o l l o w i n g pages. The pro j e c t s are arranged i n numerical order t o correspond w i t h the o r i g i n a l formulation of the program. 815

SPECIAL RESEARCH Project 50.1 - Inv e s t i g a t i o n s of S o l a r - T e r r e s t r i a l Problems 1. Objectives. This work, under the supervision of Dr. John A. Simpson, Enrico Fermi I n s t i t u t e f o r Nuclear Studies, was d i r e c t e d to analysis of IGY data bearing on solar phenomena and r e s u l t i n g t e r r e s t r i a l e f f e c t s . 2. Operations and Results. Distinguished s c i e n t i s t s from the U.S. and other countries v i s i t e d the Un i v e r s i t y and p a r t i c i p a t e d m the program. These include Dr. Reimar Lust, Max Plank I n s t i t u t fuer Physik, Munich, Dr. H. G h i e l m e t t i , National Research Council of Argentina, who worked more than a year on analysis of the great solar p a r t i c l e events of July 1959, and Dr. I . Escobar, D i r e c t o r , Chacaltaya Laboratory, B o l i v i a , who worked w i t h the group to e s t a b l i s h a new cosmic ray neutron monitor at Chacaltaya and also on the analysis of the July 1959 events. Dr. Scott Forbush (Carnegie I n s t i t u t i o n of Washington) came to Chicago so that the use of t e r r e s t r i a l magnetic data i n analysing Explorer VI data i n the period 7 August - 6 October 1959 could be explored. Dr. A. Dessler (Lockheed - Palo A l t o ) spent a period of time w i t h the group to consider the evidence f o r the neutron decay hypothesis f o r the o r i g i n of the outer e l e c t r o n r a d i a t i o n b e l t s . Other work c a r r i e d out included: a. A search f o r small bursts of cosmic r a d i a t i o n f o l l o w i n g solar f l a r e s . During 1951 and 1952 there was evidence that small i n t e n s i t y increases occurred i n association w i t h solar f l a r e s . Using neutron i n t e n s i t y monitor data during the f i r s t phases of the new solar cycle, however, preliminary analysis by us a t t h i s labor- a t o r y , and very r e c e n t l y reported by Lockwood at New Hampshire, indicates that t h i s does not seem to be the case a t present. Therefore, the use of IGY data on a g l o b a l scale has been undertaken to s e t t l e t h i s question. I t i s possible t h a t these bursts are dependent upon the "age" of the solar cycle. b. Studies were undertaken to a s c e r t a i n the r e l a t i o n s h i p s between solar plasma bursts and consequent sharp decreases observed i n cosmic ray i n t e n s i t y . The program was designed to determine how l o c a l the electromagnetic phenomena c r e a t i n g the sharp decreases are i n space. c. Changes i n the primary spectrum of cosmic rays over a solar cycle have been proved by experiments we have undertaken since 1949, and more r e c e n t l y have been v e r i f i e d and extended by experiments a t Minnesota and elsewhere. Studies were under- taken to provide a general d e s c r i p t i o n f o r the changes i n spectrum over the solar cycle, and a d e f i n i t i o n of the d e t a i l s of the cosmic ray modulation mechanism. d. I n a d d i t i o n to the research studies begun under t h i s grant, some e f f o r t has been put i n t o learning how to analyze data w i t h the aid of IBM computer equipment and learning how to handle data processing. 3. Bibliography. C. Y. Fan, P. Meyer and J. A. Simpson- "Trapped and Cosmic Radiation Measure- ments from Explorer V I . " Space Research, Ed. by H. Kallmann, No. Holland Pub. Co., Amsterdam, pp. 951-966, 1960. C Y. Fan, P. Meyer and J. A. Simpson "Cosmic Radiation I n t e n s i t y Decreases Observed at the Earth and i n the Nearby Planetary Medium." Phys. Rev. L e t t e r s , Vol 4, pp. 421-423, 1960. 816

SPECIAL RESEARCH C. Y. Fan, P. Meyer and J. A. Simpson- "Rapid Reduction of Cosmic- Radiation I n t e n s i t y Measured i n I n t e r p l a n e t a r y Space." Phys. Rev. L e t t e r s , Vol. 5, p. 269, 1960. C. Y. Fan, P. Meyer and J. A. Simpson "Experiments on the Eleven-Year Changes of Cosmic-Ray I n t e n s i t y Using a Space Probe." Phys. Rev. L e t t e r s , Vol. 5, p. 272, 1960 817

SPECIAL RESEARCH Project 50.2 - Preliminary Analysis of IGY Magnetic Results from Alaska Observatories 1. Objectives. This p r o j e c t under the supervision of Dr. Joseph C. Cain, Geo- physical I n s t i t u t e , U n i v e r s i t y of Alaska, was established to undertake the f o l l o w i n g studies. a. Analysis of the records obtained by the IGY d i f f e r e n t i a l magnetometer at College, Alaska. b. I n v e s t i g a t i o n of a u r o r a l e l e c t r o j e t s by means of magnetic records obtained from the Alaska network of observatories. 2. Operations and Results. Dr. Cam reported on e a r l y r e s u l t s of t h i s work a t the F o r t i e t h Annual Meeting of the American Geophysical Union, 8 A p r i l 1959, Washington, D. C, and a te c h n i c a l report i s i n preparation. Professor S. Chapman and Mr. Syun Akasofu c o l l e c t e d extensive data from around the world on the s o l a r - t e r r e s t r i a l events of July 1959. 3. Bibliography. a. Papers presented at the X I I General Assembly of the I n t e r n a t i o n a l Union of Geodesy and Geophysics, H e l s i n k i , 1960 "General Magnetic A c t i v i t y i n the Period July 11-18, 1959" S. Chapman and S. Akasofu. "On the Large Negative Impulse A f t e r the Sudden Commencement of the Magnetic Storm on July 15, 1959." S. Akasofu and S. Chapman. "Analysis of the Magnetic Storm on July 15, 1959." M. Sugiura, S. Akasofu and J. A. Dawson. 818

.SPECIAL RESEARCH Project 50.3 - IGY P i l o t Studies 1. Objectives. The purpose of t h i s p r o j e c t a t the High A l t i t u d e Observatory was to conduct several exploratory studies using the new solar and geophysical data of the IGY. The i n v e s t i g a t i o n s were not intended to be necessarily exhaustive, but rather a searching f o r the p o t e n t i a l usefulness of the data f o r l a t e r research. I n t h i s way, i t was hoped to be able to improve c e r t a i n phases of data-taking programs during the IGY. 2. Operations and Results. The work f e l l p r i n c i p a l l y i n t o two categories, a.) geomagnetic or ionospheric research by Sadami Matsushita, and b.) solar work of Donald B i l l i n g s . Dr. Matsushita and h i s associates studied the geomagnetic and ionospheric e f f e c t s of the nuclear explosions i n the P a c i f i c of August 1958. Strong counter- clockwise c i r c u l a r e l e c t r i c a l currents were formed i n the v i c i n i t y of Johnston Is l a n d at 80-100 km a l t i t u d e . These currents caused the immediate occurrence of magnetic storms i n the c e n t r a l P a c i f i c . High energy p a r t i c l e s moving along magnetic l i n e s of force caused auroras, and X-rays from the explosion caused an increase of D-region absorption as observed i n the Hawaiian Islands. I r r e g u l a r F-region e l e c t r o n density was also observed and a t t r i b u t e d to a pressure wave. Matsushita also analysed data from seven geomagnetic s t a t i o n s i n the U. S. From the behavior of the sudden commencement ( h o r i z o n t a l component) of magnetic storms, behavior of the ionospheric e l e c t r i c current system responsible f o r the storm was estimated. Be- havior of the v e r t i c a l component showed that the f i e l d i s anomalous i n c e n t r a l U. S. F i n a l l y , an analysis was made of the great solar-geophysical coupling r e s u l t i n g i n the events of February 10/11, 1958. E l e c t r i c current systems were estimated from magnetograms and the increase of i o n i z a t i o n calculated from lonograms. The physical behavior of the ionosphere during the storm, p a r t i c u l a r l y from 6:00 to 7.00 UT on February 11, was constructed. Dr. B i l l i n g s and h i s associates have c a r r i e d out a number of studies designated b e t t e r to organize information on various solar phenomena. For example, a study was made of the o p t i c a l depth, as a f u n c t i o n of wavelength, i n the p r o f i l e of the hydrogen alpha emission from small f l a r e s . The basic idea was to compare the p r o f i l e of f l a r e s seen against the solar disc w i t h those seen against a less b r i l l i a n t back- ground, as sunspots, or the sky i n the case of limb f l a r e s . I t was found that f l a r e s seen against sunspots d i f f e r m apparent p r o f i l e from those seen against the undisturbed photosphere. An e m p i r i c a l computation of f l a r e opacity as a f u n c t i o n of wavelength was made. I t was also found t h a t a f l a r e has the same shape and p r o f i l e against the photosphere and chromosphere but t h a t there i s a sudden change m pro- f i l e at the point where the f l a r e protrudes above the chromosphere. Another study involved an analysis of average i n t e n s i t y height gradients i n the corona, the average being c a r r i e d out over whole coronal regions. Spectrograms were catalogued and t h i s work proved u s e f u l to personnel using spectrograms f o r research on solar phenomena. A study was c a r r i e d out of the r e l a t i o n between features seen i n H-alpha spectrograms a t the solar limb and the subsequent flare-producing tendencies of the region e x h i b i t i n g these features. The limb c h a r a c t e r i s t i c s of the solar plage was studied, using the d a i l y H-alpha photographs supplied by various observatories to the IGY World Data Center-Solar A c t i v i t y , located a t HAG. From an examination of the geometry of the l o c a t i o n of height features i n the spectra of red and green coronal l i n e s . Dr. B i l l i n g s derived a t e n t a t i v e hypothesis of thermal s t r u c t u r e i n the corona: there are comparatively dense filaments of coronal gas w i t h cross sections of about one degree, w i t h temperatures i n the range 2.0 to 2.6 m i l l i o n degrees K, larger filaments or loops are more l i k e l y to have complex i n t e r n a l temperature s t r u c t u r e s . The study of a flare-surge that occurred on September 7, 1958, provided a comprehensive documentation of t h i s solar process. I n a study leading to a master's t h e s i s , one of B i l l i n g s ' students found, from examination of IGY data on the green coronal l i n e of Fe XIV, an enhancement of s t a t i s t i c a l importance 20-24 hours before an appearance of surges. 819

SPECIAL RESEARCH 3. Bibliography. Matsushita, Sadami. "Geomagnetic and Ionospheric Phenomena Associated w i t h Nuclear Explosions." Nature, Vol. 184 (September 5, 1959), pp. 33-34. Matsushita, Sadami- "IGY P i l o t Studies f o r Geomagnetic Data Made at a Closely Spaced Net of Seven Stations i n the United States." High A l t i t u d e Observatory Solar Research Memorandum No. 119, 24 November 1958. Matsushita, Sadami- "On A r t i f i c i a l Geomagnetic and Ionospheric Storms Associated w i t h H i g h - A l t i t u d e Explosions." Journal of Geophs. Res., Vol. 64, p. 9, September 1959. Matsushita, Sadami- "On the Association Between the Ionosphere and a Severe Magnetic Storm of February 10-11, 1958." Paper presented to Washington meeting of U.R.S.I., May 1959. Matsushita, Sadami: "Physical Behavior of the Atmosphere Near the 100 Km Level Deduced from Geomagnetic V a r i a t i o n s . " Paper presented to the F i r s t National Conference on the High Atmosphere, E l Paso, Texas, October 1958. Alam, Mohammed- "Association of the Green Coronal Line w i t h Surges." 10 August 1959. (Thesis submitted as p a r t i a l requirements f o r M. S., Astrogeophysics), U n i v e r s i t y of Colorado. Available a t the U n i v e r s i t y of Colorado L i b r a r y . Alam, Mohammed and Donald B i l l i n g s "Protrusion of H-alpha Plage a t the Limb of the Sun." High A l t i t u d e Observatory Solar Research Memorandum No. 116, 10 September 1958. B i l l i n g s , Donald "Relation of B r i g h t Features m X5303 and X6374 on Sacramento Peak Spectrograms." High A l t i t u d e Observatory Solar Research Memorandum No. 117, 5 November 1958. Cooper, Robert. "Coronal Emission I n t e n s i t y Gradients." High A l t i t u d e Observatory Solar Research Memorandum No. 105, 7 May 1958. Robb, James "Solar Flare C l a s s i f i c a t i o n . " High A l t i t u d e Observatory Solar Research Memorandum No. 113, 11 August 1958. Z i r i n , Mary: "Recent Climax Spectrograms, 15 August 1955-31 December 1957." High A l t i t u d e Observatory Solar Research Memorandum No. 103, 17 A p r i l 1958. 820

SPECIAL RESEARCH Project 50.4 - Research on IGY Airglow, Ionosphere and Solar A c t i v i t y Data 1. Ob.iectives. The purpose of t h i s p r o j e c t , a t the High A l t i t u d e Observatory, was to conduct studies of the ionosphere using the IGY airglow, ionosphere and solar a c t i v i t y data. 2. Operations and Results. G. A. M. King, Geophysical Observatory, Christchurch, New Zealand, spent a year at Boulder working w i t h his colleagues at High A l t i t u d e Observatory and the Central Radio Propagation Laboratory, National Bureau of Standards, on IGY data. Mr. King worked on a computer program to convert lonogram traces to give true height data using a logarithmic sampling of the frequency scale. Instead of the equal frequency i n t e r v a l method commonly used. The logarithmic program i s more f l e x i b l e , gives promise of greater accuracy, and can also be applied to the extraordinary lonogram trace. Associated w i t h his work, Mr. King was connected w i t h a program of low frequency soundings, which also gave information on nighttime i o n i z a t i o n i n the E-region I t appears that t h i s i o n i z a t i o n i s r e l a t e d to the behavior of ionospheric storms. Another part of the work was devoted to studies of photochemical processes i n the ionosphere. One aspect of t h i s a c t i v i t y was the study of a p a r t i c u l a r kind of a u r o r a l arc which emits only the oxygen red l i n e . These arcs have been i d e n t i f i e d w i t h c h a r a c t e r i s t i c traces on lonograms which enabled the development of a theory of the emission based on e l e c t r o n recombination. The success of t h i s theory has led to clearer ideas on the r o l e of molecular n i t r o g e n i n the upper atmosphere and on the heating and mixing of the atmosphere near an a l t i t u d e of 100 km during an a c t i v e a u r o r a l d i s p l a y . Other photochemical studies were concerned w i t h e l e c t r o n recombi- nation under qui e t conditions and gave information on the d i f f u s i v e separation of atomic and molecular constituents of the atmosphere. 3. Bibliography. G. A. M. King: "Use of Logarithmic Frequency Spacing i n lonogram Analysis," J. of Res., Nat. Bur. Standards, Vol. 64D, No. 5, pp. 501-4. G. A. M. King, F. E. Roach. "Relationship Between Red Auroral Arcs and Ionospheric Recombination," J. of Res., Nat. Bur. Standards, Vol. 65D, No. 2, pp. 129-35. 821

SPECIAL RESEARCH Project 50.5 - Research on Problems of the Solar Atmosphere, Magnetic Storms and Cosmic Rays 1. Objectives. The purpose of t h i s p r o j e c t , at the High A l t i t u d e Observatory, was to conduct research using IGY geophysical data on solar and s o l a r - t e r r e s t r i a l problems. 2. Operations and Results. Mr. Kin-Aki Kawabata, Tokyo Astronomical Observatory, Un i v e r s i t y of Tokyo, spent a year at HAO working w i t h colleagues on solar and solar- t e r r e s t r i a l problems. He concluded a t h e o r e t i c a l study of the coronal condensation, based on s t a t i s t i c a l i n v e s t i g a t i o n s of the slowly varying component of the solar radio emission, the temperature and o p t i c a l depth of the coronal condensation associated w i t h intense calcium plages were obtained. He also studied t r a n s i e n t e f f e c t s i n the solar microwave spectrum i n which he considered solar X-ray emission associated w i t h radio observations and t e r r e s t r i a l ionospheric e f f e c t s f o r a p a r t i c u l a r event. Kawabata concluded t h a t a high temperature region, 2 x 10^ degrees K, may produce the observed X rays of wavelength greater than 2 A as w e l l as the observed radio emission. This thermal model, however, cannot account f o r X rays below 0.6A, which apparently are bremsstrahlung by superthermal electrons of energy greater than 20 kev. 3. Bibliography. K-A Kawabata: "A thermal O r i g i n of the Post-Burst Increases of Solar Microwave Radiation," unpublished manuscript, H. A. 0., Boulder, Colorado, ca. 1960. K-A Kawabata: "A Model of the Coronal Condensation," unpublished manuscript, H. A. 0., Boulder, Colorado, ca. 1960. 822

SPECIAL RESEARCH Project 50.6 - Studies i n Ionospheric Physics and Airglow 1. Objectives. The purpose of t h i s p r o j e c t at the High A l t i t u d e Observatory was to conduct research on the ionosphere m polar regions, using IGY geophysical data. 2. Operations and Results. Mr. R. A. Duncan, Upper Atmosphere' Section, Common- wealth S c i e n t i f i c and I n d u s t r i a l Research Organization of A u s t r a l i a , spent a year as a v i s i t i n g worker at HAO working w i t h colleagues there and at the Central Radio Propagation Laboratory of the National Bureau of Standards on analysis of IGY data. He completed a study of the a r c t i c and a n t a r c t i c ionosphere, during which he studied the behavior of the F-region near the pole w i t h the hope of explaining the main- tenance of t h i s region during the long winter n i g h t , and the marked d i u r n a l v a r i a t i o n m t h i s region i n the absence of a d i u r n a l v a r i a t i o n of solar z e n i t h angle. The analysis of the lonosonde data revealed that polar F-region e l e c t r o n d e n s i t i e s are c o n t r o l l e d by u n i v e r s a l time. This i s p a r t i c u l a r l y marked i n the A n t a r c t i c , there i n summer uni v e r s a l time c o n t r o l extends as f a r n o r t h as a l a t i t u d e of 43°. In t h i s context u n i v e r s a l time c o n t r o l indicates simply that although there i s a v a r i a t i o n m the ionosphere w i t h a 24 hour period, i t takes place simultaneously throughout the polar cap, independent of longitude. Electron d e n s i t i e s increase almost simultaneously, a c t u a l l y a l i t t l e e a r l i e r at the pole than i n the surrounding areas, and t h e r e f o r e , i t seems u n l i k e l y t h a t d r i f t from surrounding s u n l i t areas i s a major source of i o n i z a t i o n . Duncan compared the month-to-month v a r i a t i o n s of F-region e l e c t r o n d e n s i t i e s at magnetically conjugate s t a t i o n s near the north and south poles. This comparison, however, gives l i t t l e support to the idea of " d i s t i l l a t i o n " of ions from the summer to the winter poles along geomagnetic f i e l d l i n e s . Furthermore, the nature of the d i u r n a l v a r i a t i o n and other q u a n t i t a t i v e considerations tend to discount the idea that i o n i z a t i o n may be produced by s u n l i g h t at great a l t i t u d e s and subsequently d i f f u s e down to F-region heights. Thus an explanation f o r the universal-time c o n t r o l of the polar winter ionosphere i s yet to be found. Duncan also collaborated w i t h F. E. Roach and D. Barbier i n the analysis of a red a u r oral arc of great extent that was observed i n France, the United States, and A u s t r a l i a . 3. Bibliography. R. A. Duncan "Universal-Time Control of the A r c t i c and A n t a r c t i c F-Region," JGR, Vol. 67, No. 5, pp. 1823-30, May 1962. F. E. Roach, D Barbier, R. A. Duncan "Observation of a 6300A Arc i n France, The United States and A u s t r a l i a . " Ann de. Geophys. Vol. 18, No. 4, Dec. 1962, pp. 390-91. 823

SPECIAL RESEARCH Project 50.7 - Studies of Earth's Gravity 1. Objectives. This p r o j e c t , under George P. Woollard, U n i v e r s i t y of Wisconsin, was an e f f o r t to c a p i t a l i z e on IGY experience, to r e c t i f y points of weakness m procedure such as repeating a l l observations on the North American l i n e i n ladder sequence, i . e . A-B-C-D-D-C-B-A, t o obtain closures on each s i t e , upgrading equipment to obtain higher p r e c i s i o n and pic k i n g up loose ends such as repeating poor con- nections, t y i n g out points of doubtful r e l i a b i l i t y and at the same time expanding e x i s t i n g coverage and t y i n g i n areas where there were e x i s t i n g data which might be released i n the f u t u r e . 2. Operations and Results. The Point Barrow-Mexico City l i n e of g r a v i t y standard- i z a t i o n measurements w i t h both the Gulf pendulums and gravimeters was repeated a f t e r the pendulum recorder and c r y s t a l clock were r e b u i l t i n order to improve the q u a l i t y of the pendulum data. Extensive laboratory t e s t s were c a r r i e d out on the e f f e c t of pressure and temperature on the response of the gravimeters, i n p a r t i c u l a r the time required to reach reading s t a b i l i t y a f t e r having been i n a low pressure environment such as i s encountered when using plane t r a n s p o r t . A d e t a i l e d weight c a l i b r a t i o n t e s t was made for both gravimeters to t r y to determine evidence of e r r a t i c response and to i d e n t i f y those parts of the scale that were a f f e c t e d . Both programs i n instrument improvement contr i b u t e d to improved r e s u l t s on the standardization range. 3. Bibliography. George P. Woollard, R. L. Longfield and B. A. Carlson "Gravity Standard- i z a t i o n Studies." W. H. 0. I . Rep. 62-63, 114 pp., 1962. George P. Woollard "An Evaluation of the Potsdam Datum." Hawaii I n s t i t u t e of Geophysics, 52 pp., 1963. G. P. Woollard and J. C. Rose. " I n t e r n a t i o n a l Gravity Measurements." Soc. Expl. Geophys., 518 pp., 1963. 824

SPECIAL RESEARCH Project 50 8 - Studies of A n t a r c t i c Ice Stratigraphy 1. Objectives. The purpose of t h i s p r o j e c t at the I n s t i t u t e of Polar Studies, Ohio State U n i v e r s i t y , was to conduct studies of the glaciology data obtained during the IGY i n A n t a r c t i c a . 2. Operations and Results. Dr. Kenj i Kojima, I n s t i t u t e of Low Temperature Science, Hokkaido U n i v e r s i t y , Sapporo, Japan, worked for a year w i t h Dr. R. P. Goldthwait, I n s t i t u t e of Polar Studies, studying the data from snow and ice p i t measurements obtained during the IGY i n A n t a r c t i c a . Dr. Kojima i s a recognized s p e c i a l i s t i n t h i s f i e l d of work and has published many papers on ice physics i n the Japanese l i t e r a t u r e . The analysis of the mass of IGY data i s an important s c i e n t i f i c under- taking and, i n a d d i t i o n , provides c r u c i a l information i n planning f u t u r e observations i n A n t a r c t i c a . Dr. Kojima analyzed snow density data from observations made at many st a t i o n s during U. S. A n t a r c t i c traverses during and a f t e r IGY, and made a t h e o r e t i c a l study of the density p r o f i l e s from the surface to a depth of 10 meters. The r e s u l t s were published i n the AGU A n t a r c t i c Research Series. I n t h i s r e p o r t , the r e l a t i o n between compactive v i s c o s i t y f a c t o r (v) and density ( r ) i s derived from the observed density p r o f i l e s and the accumulation r a t e . I t i s found t h a t log V increases i n proportion to density i n the middle range of den s i t i e s usually observed at traverse s t a t i o n s . Such a l i n e a r r e l a t i o n between log V and density i s expressed V = Cexp ( k r ) where C and k are constants independent of density. A l l the st a t i o n s or s t a t i o n groups can be divided i n t o two main groups. The value of k averages 24 cm^/g f o r one group and 20 cm^/g f o r the other. C depends mainly on temperature. C should also depend on average g r a i n s i z e , but the observed data on g r a i n size do not pro- vide a clear r e l a t i o n s h i p . T h e o r e t i c a l depth-density curves were considered i n d e t a i l , i n c l u d i n g various modifications to take i n t o account the departures of the observed values from the predicted. Ten-meter density i s e s p e c i a l l y high at the sta t i o n s northwest of the H o r l i c k Mountains and a t Wilkes s t a t i o n but i s qu i t e low at South Pole, V i c t o r i a Land plateau, and Ross ice s h e l f . Most of these values, except f o r Ross ice s h e l f , can be explained t h e o r e t i c a l l y w i t h some re-estimated values of the accumulation rate (Figure 1). Byrd s t a t i o n and i t s v i c i n i t y are pe c u l i a r , as there i s low density i n the upper layers above 5 meters. 3. Bibliography. Kenji Kojima " D e n s i f i c a t i o n of Snow i n A n t a r c t i c a . " AGU A n t a r c t i c Research Series, No. 2, pp. 157-215, 1964. 825

SPECIAL RESEARCH 0 70 BH4I4 BH747 D 0 6 0 2 0 55 O OBSERVED VALUES ISM-DENSITY 01 • 9 S P / > « 10 M-DENSITY X B 5 7 • N V 5 9 <D BH5B A RS57 Z O i O • Bsg e s s -BYRo S T A T I O N S E I S M I C A R E A . 1958 O EH 60 B , - — B Y R O , 1 9 5 7 e W — W I L K E S e B , — B Y R O , I960 9 M—MAUOHEIM E L — E L L S W O R T H e .SP " S O U T H POLE ISM AND 10 M DENSITY VS ANNUAL AVERAGE SNOW TEMPERATURE THEORETICAL RELATIONS) CURVES I S M - D E N S I T Y * ' 10 M - DENSITY f I'j j ! ' /V03e ^OAO GM'CM-* 0 4 5 -10 - 2 0 - 3 0 - 4 0 ANNUAL AVERAGE SNOW T E M P E R A T U R E IN " C -SO -60 Figure 1. Theoretical and observed v a r i a t i o n of 15- and 10-meter density according to various average snow temperatures. T h e o r e t i c a l curves are shown f o r d i f f e r e n t accumulation rates and two d i f f e r e n t i n i t i a l d e n s i t i e s are described i n the f i g u r e . Observed d e n s i t i e s at the depths of 10 and 15 meters are p l o t t e d against 10-meter snow temperature. The number attached to a p l o t t e d p o i n t i s the group number or the s t a t i o n number of the traverse. 826

SPECIAL RESEARCH Project 50.9 - Geomagnetic I n v e s t i g a t i o n s of IGY Data 1. Objectives. The purpose of t h i s p r o j e c t was to conduct studies of the IGY geomagnetic data to determine geomagnetic v a r i a t i o n s . 2. Operations and Results. Dr. A. T. Price, Department of Mathematics, U n i v e r s i t y of Exeter, England, spent a year i n the United States working w i t h IGY geomagnetic data m cooperation w i t h colleagues a t the U. S. Coast and Geodetic Survey. Dr. Price undertook, f o r planning purposes i n connection w i t h the IQSY program, a study of desirable s t a t i o n d i s t r i b u t i o n f o r determining the geomagnetic q u i e t day (Sq) v a r i a t i o n i n the P a c i f i c area. He worked on analysis of d a i l y magnetic v a r i a t i o n s during IGY and non-cyclic v a r i a t i o n s during q u i e t days of the IGY. The l a t t e r study showed that the Sq f i e l d i s mainly zonal about the geomagnetic axis but w i t h s i g n i f i c a n t departures from a x i a l symmetry. The zonal part corresponds clos e l y to a uniform f i e l d plus a dipole f i e l d along the geomagnetic a x i s . I n association w i t h Dr. L. R. Alldredge, he studied observations of d a i l y magnetic v a r i a t i o n s a t sea, e s p e c i a l l y i n the P a c i f i c area. Dr. Price published a t h e o r e t i c a l study of magnetotelluric methods w i t h a p p l i c a t i o n to measurements at sea and to determination of c o n d u c t i v i t y a t great depths. 3. Bibliography. A. T. Price. "The Theory of Magnetotelluric Methods when the Source F i e l d i s Considered," JGR, Vol 67, No. 5, pp. 1907-18, May 1962. A. T. Price "The Noncyclic V a r i a t i o n during Quiet Days," JGR, Vol. 68, No. 24, pp. 6383-89, Dec. 15, 1963. 827

SPECIAL RESEARCH Project 50.10 - Analysis of IGY Seismic Data 1. Objectives. The purpose of t h i s p r o j e c t was to conduct studies of after-shock sequences using IGY seismic data. 2. Operations and Results. Dr. T o k u j i Utsu, Seismological Section, Japan Meteoro- l o g i c a l Agency, Tokyo, was i n v i t e d to spend a year i n the United States working w i t h his colleagues on studies based on the IGY data. He was recommended by Professor Tsuboi, Tokyo U n i v e r s i t y , one of the foremost geophysicists i n Japan. Dr. Utsu spent h i s time a t the U. S. Coast and Geodetic Survey, p r i m a r i l y to make a study of after-shock sequences. He was able to make considerable use of World Data Center A i n connection w i t h h i s major study, an evaluation of the nature of after-shock sequences which occurred during the IGY. These sequences followed three large Alaskan earthquakes. 9 March 1957, Aleutians near Adak, magnitude 8.3, 7 A p r i l 1958, west c e n t r a l Alaska near Seward Peninsula, magnitude 7.3, 10 July 1958, southeast Alaska (Glacier Bay), magnitude 7.9. Utsu studied the d i s t r i b u t i o n of after-shocks w i t h respect to frequency and time. I t had been shown by Utsu that f o r after-shock sequences m Japan, frequency of after-shocks w i t h magnitude greater than a f i x e d value decreases w i t h time according to the equation n ( t ) A/ ( t + c)P i n which n ( t ) d t denotes the frequency of a f t e r - shocks occurring between time t and ( t + d t ) , w i t h t measured from the time of the main shock. A, c and £ are p o s i t i v e constants. I t was shown that the Alaskan sequences f o l l o w i n g the same equation, that the magnitude-frequency r e l a t i o n i s independent of time, the time-frequency r e l a t i o n independent of magnitude. The p l o t s of these two r e l a t i o n s are reproduced f o r the c e n t r a l Alaskan earthquakes (see f i g u r e 1 and 2 ) . The f l u c t u a t i o n of frequency i n time frequency d i s t r i b u t i o n I S nearly that which i s to be expected i n random sampling from a population whose frequency d i s t r i b u t i o n i s exactly expressed by the equation above. The r e g i o n a l v a r i a t i o n i n the mode of after-shock occurrence m t h i s area seems to be d i f f e r e n t from sequence to sequence and no general laws are obtainable. For example, f o r the A l e u t i a n after-shock sequence the c e n t r a l p art of the after-shock area i s characterized by a comparatively small energy release and a small value of c i n the equation, f o r the southeastern Alaska after-shock sequence the greatest a c t i v i t y i s concentrated near the epicenter of the main shock and no geographical v a r i a t i o n i n magnitude and time-frequency d i s t r i b u t i o n i s ind i c a t e d . 3. Bibliography. T o k u j i Utsu- "On the Nature of Three Alaskan After-Shock Sequences of 1957 and 1958," B u l l . Seis. Soc. Amer., Vol. 52, No. 2, pp. 279-297, 1962. T o k u j i Utsu: "A S t a t i s t i c a l Study on the Occurrence of After-shocks," Geophys. Mag., Vol. 30, No. 4, 521-605, 1961, Tokyo. 828

SPECIAL RESEARCH 1000 100 10 A •> Apr 8 B - Apr. 8 - 9 C» Apr 8 - 1 2 I D- Apr 8 - 2 0 E " Apr. 8 - J u n e 8 - - A V \ \ \ \ - M Figure 2. Cumulative frequency d i s t r i b u t i o n of magnitude f o r the c e n t r a l Alaska aftershock sequence. n(t) 10 1 1 1 1 B \ _C >^ - - A = M ^ 3 5 I B = M ^ 3 9 ^ C = M > 4 3 \/\ \ /W \ - 1 1 1 1 ' '0 t lOOdoyt Figure 3. Decrease i n frequency of the c e n t r a l Alaska aftershocks w i t h time. 829

SPECIAL RESEARCH Project 50.11 - Studies Based on Sea and Earth Tide Data 1. Objectives. The purpose of t h i s p r o j e c t a t the I n s t i t u t e of Geophysics, Un i v e r s i t y of C a l i f o r n i a at Los Angeles, was to conduct studies of long period earth waves and e l a s t i c phenomena using IGY data on e a r t h t i d e s and r e l a t e d phenomena. 2. Operations and Results. Drs. Georges and N e l l i e Jobert, I n s t i t u t e de Physique du Globe de Pans, were i n v i t e d to work w i t h t h e i r colleagues a t the U n i v e r s i t y of C a l i f o r n i a , making use of the IGY data on e a r t h tides and r e l a t e d phenomena. Dr. G. Jobert, has worked on t h e o r e t i c a l problems of long period earth waves and e l a s t i c phenomena, and Dr. N. Jobert i s an a u t h o r i t y on e l a s t i c and dynamic t e r - r e s t r i a l phenomena, in c l u d i n g the free mode v i b r a t i o n of the earth. The r e s u l t s of the studies c a r r i e d out by the Joberts were published i n four papers. The authors' summaries f o l l o w a. By f o l l o w i n g the e v o l u t i o n of the stresses i n a g r a v i t a t i n g homogeneous planet during i t s a c c r e t i o n , i t was possible to evaluate the d i f f e r e n t i a l stress i n I t s i n t e r i o r i f the c o m p r e s s i b i l i t y and the r i g i d i t y of the substance are known functions of the density. The s u p e r f i c i a l layers were assumed to be i n h y d r o s t a t i c e q u i l i b r i u m . The r a d i a l pressure everywhere exceeded the h o r i z o n t a l pressures. The stress d i f f e r e n c e was n u l l at the center of the planet, reaching i t s maximum at a depth of about one-third of the e x t e r n a l radius. This value i s roughly pro- p o r t i o n a l to the f o u r t h power of the e x t e r n a l radius and inversely p r o p o r t i o n a l to the s u p e r f i c i a l r i g i d i t y . b. Using Birch's formulae f o r the density and the e l a s t i c parameters i n terms of the compression, and the equation f o r the h y d r o s t a t i c a l e q u i l i b r i u m , they obtained by numerical i n t e g r a t i o n s the values of these parameters i n the i n t e r i o r of a g r a v i t a t i n g , homogeneous isothermal planet. D i s c o n t i n u i t i e s a t various depths were also introduced. The method was also applied to the Moon and to the t e r - r e s t r i a l planets. The Moon and Mars seemed to be homogeneous. Mercury and Venus have probably a m e t a l l i c core. I f the density of the matter under zero pressure i s 3.3 g/cm? f o r the mantle, 7.87 f o r the core, the f o l l o w i n g r a t i o s of the core's radius to e x t e r n a l radius have been found Mercury, 0.715--0.730, Venus, 0.465-- 0 517, Mars, 0.465--0.489. The case of the Earth shows that the value of the density chosen f o r the core i s probably too high, the radius found f o r the t e r - r e s t r i a l core I S nevertheless near the known value of 3470 km. c. The great Chilean earthquake of May 22, 1960, has been recorded by three f u s e d - s i l i c a t i l t m e t e r s f o r earth tid e s at the I n s t i t u t de Physique du Globe de Pans. A s p e c t r a l analysis using a Fourier transform has been performed on the records. I n the spectrum obtained, the peaks of the free o s c i l l a t i o n s of the Earth appear from order n = 4 up to 40 f o r spheroidal o s c i l l a t i o n s , and from n = 4 up to 35 f o r t o r s i o n a l o s c i l l a t i o n s . The observed periods are m good agreement w i t h r e s u l t s i n other s t a t i o n s , and w i t h t h e o r e t i c a l r e s u l t s f o r B. Gutenberg's model. d. The purpose of the study was to c a l c u l a t e the displacement due to t o r s i o n a l o s c i l l a t i o n s , a t a point of the t e r r e s t r i a l surface, the i n i t i a l motion a t the focus was schematized by a sudden r o t a t i o n ( u n i t - s t e p f u n c t i o n ) of a very small sphere w i t h a v e r t i c a l r o t a t i o n a x i s , f o r a more general i n i t i a l motion, the displacement calculated could be used w i t h an i n t e g r a t i o n . 830

SPECIAL RESEARCH I n the f i r s t p a r t the t h e o r e t i c a l expression of the displacement was c a l - c u l a t e d , and given as a series of s p h e r i c a l f u n c t i o n s , each term of which represents a standing o s c i l l a t i o n of order n. An a p p l i c a t i o n was made to the Gutenberg con- t i n e n t a l model, and to an oceanic model not very d i f f e r e n t from Dorman's 8099. V a r i a t i o n of the amplitude of each o s c i l l a t i o n w i t h i t s order, was given i n the second p a r t , f o r 4 f o c a l depths. With the method used here one obtains r e s u l t s f o r orders n up to 350. I n case of a source near the surface, the s p e c t r a l amplitude decreases toward short periods, more s t r o n g l y f o r the oceanic model than f o r the c o n t i n e n t a l one. I n the t h i r d p a rt a few synthetic seismograms were calculated i n a s p e c t r a l range such t h a t the o s c i l l a t i o n s appeared clustered, as separated t r a v e l i n g Love- waves. The oceanic model was not s a t i s f a c t o r y , owing to p e c u l a r i t i e s of the dispersion curve, b e t t e r r e s u l t s were obtained using the experimental dispersion of G waves. 3. Bibliography. Georges Jobert: "Nonhydrostatical Stresses i n a G r a v i t a t i n g Planet." Journal of Geophysical Research Vol. 67, No. 4, pp. 1579-1585, A p r i l 1962. Georges Jobert: "Modeles de R e p a r t i t i o n des Densites Dans Les Planetes Terrestres," E x t r a i t des Annales de Geophysique, Vol. 18, No. 2, pp. 133-149, April-June, 1962. J. Connes, P. A. Blum, G. Jobert and N. Jobert- "Observation des O s c i l l a t i o n s Propres de l a Terre," E x t r a i t des Annales de Geophysique, Vol. 18, No. 3, pp. 260-268, July-September, 1962. N. Jobert: " E x c i t a t i o n des O s c i l l a t i o n s Propres de Torsion de l a Terre," Vol. 18, No. 4, pp. 372-384, October-December 1962. 831

SPECIAL RESEARCH Project 50.12 - I n v e s t i g a t i o n s of Solar Radio Emissions 1. Objectives. The purpose of t h i s p r o j e c t a t the High A l t i t u d e Observatory was to conduct studies of solar radio emissions using IGY data. 2. Operations and Results. Dr. S. F. Smerd, CSIRO of A u s t r a l i a , spent one year at HAO studying the IGY solar radio data and working w i t h colleagues on systematizing and analysing the data. Nine large s o l a r - t e r r e s t r i a l disturbances were analysed w i t h respect to r e l a t i o n s h i p s between solar events, o p t i c a l and r a d i o , and ensuing t e r r e s t r i a l disturbances. I n d i v i d u a l s o l a r - r a d i o aspects were also i n v e s t i g a t e d , such as emission from the q u i e t sun (during maximum of the solar a c t i v i t y c y c l e ) , slowly varying component, burst a c t i v i t y , and other solar phenomena. 3. Bibliography. S. F. Smerd. "Solar Radio Emission during the IGY," unpublished manuscript, HAO, ca. 1962. S, F. Smerd: "Solar Radio Emissions," Research i n Geophysics, Vol. 1, Sun, Upper Atmosphere and Space, pp. 65-97, MIT Press, 1964. 832

SPECIAL RESEARCH Project 50.13 - G l a c i o l o g i c a l Studies a t Wilkes S t a t i o n , Budd Coast, A n t a r c t i c a 1. Objectives. The purpose of t h i s p r o j e c t at the I n s t i t u t e of Polar Studies, Ohio State U n i v e r s i t y , was to complete and present the r e s u l t s of gl a c i o l o g y i n v e s t i g a t i o n s m the v i c i n i t y of Wilkes S t a t i o n during the ICY. 2. Operations and Results. G l a c i o l o g i c a l studies were conducted at and i n the v i c i n i t y of Wilkes s t a t i o n as part of the US-IGY program i n A n t a r c t i c a ; data reduction was c a r r i e d out at Ohio State U n i v e r s i t y as part of the IGY data reduction program--IGY Project 4.10. The reduced data were published under p r o j e c t 4.10 as Ohio State U n i v e r s i t y Research Foundation, Report 825-1 Part I I I . Under t h i s pro- j e c t . Dr. Cameron was enabled to present the r e s u l t s i n the form of a d i s s e r t a t i o n i n p a r t i a l f u l f i l l m e n t of the requirements f o r the Ph.D. degree a t Ohio State U n i v e r s i t y . The degree was awarded i n 1963. The f o l l o w i n g i s an abstract of his r e s u l t s . G l a c i o l o g i c a l studies were conducted i n the v i c i n i t y of Wilkes s t a t i o n , on the Windmill Islands, Budd Coast, East A n t a r c t i c a , from February 1957 to January 1958. The main aim of t h i s work was to determine the mass balance of the margin of the ice sheet, because the state of t h i s ice r e f l e c t s the c o n d i t i o n of the e n t i r e ice sheet. The environment of the marginal ice was determined u t i l i z i n g three meteorological s t a t i o n s : a main base at sea l e v e l ; S-1, 5 kilometers i n l a n d , a t 262-meter e l e v a t i o n , and S-2, 80 kilometers i n l a n d , a t 1166-meter e l e v a t i o n . The ice sheet inland of Wilkes s t a t i o n receives l i t t l e p r e c i p i t a t i o n from cyclones, and there i s l i t t l e snow accumulation. Stake and sha l l o w - p i t studies of snow accumulation give values ranging from 7.9 to 15.9 g cm"^ per year. Studies i n a deep p i t at S-2 give an annual mean accumulation of 13.3 g cm"^ f o r the l a s t 174 years. Between S-1 and S-2 there i s no pronounced v a r i a t i o n i n accumulation due to e l e v a t i o n or distance from the coast. Studies of lO-meter temperature from the coast to 96 kilometers inland give a lapse rate of 1.02°C per lOO-meter e l e v a t i o n . From 10- to 62-meter depth a t S-2 there i s no d i s c e r n i b l e temperature gradient. Temperature gradients i n the 10- to 28-meter depth i n t e r v a l from S-2 to S-1 are p o s i t i v e and reach +2.8°C per 100 meters a t S-1. Temperature studies a t S-1 give the f o l l o w i n g values of thermal d i f f u s i v i t y and thermal c o n d u c t i v i t y f o r ice of density o f 0.78 g cm"-̂ a (15.38 + 0.9) X 10"^ cm^sec-l K (6.56 + 0.4) X 10-3 c a l sec"! cm"'- "C^^ These values are considerably higher than those f o r pure ice of density of 0.917 g cm"-̂ , but t h i s d i f f e r e n c e I s not as yet explained. The Vanderford Glacier, south of the Windmill Islands, i s moving 2.1 meters per day and I s discharging 3.86 km3 of ice per year. T o t a l ice discharge along 167 km of Budd Coast i s 5.43 km^ of ice per year, equivalent to 4.9 km^ of water. S t r a i n studies of the ice-sheet surface at S-2 give a compressive s t r a i n rate downslope of -24 X 10"^ year-1 and an extensive s t r a i n perpendicular to the slope of +35 X 10"5 year"-'-. Ca l c u l a t i o n of the regime of the ice-sheet margin, an area of 9400 km^, indicates an excess of a b l a t i o n over accumulation of 0.16 km^ of water per year. The ice sheet i n the Budd Coast area i s t h i n n i n g , a c o n d i t i o n consistent w i t h g l a c i a l geology observations on the Windmill Islands. The g l a c i o l o g i c a l r e s u l t s were published i n the AGU A n t a r c t i c Research Series, No. 2; geological r e s u l t s w i l l be published m a subsequent number. 833

SPECIAL RESEARCH 3. Bibliography. Richard L. Cameron: " G l a c i o l o g i c a l Studies a t Wilkes S t a t i o n , Budd Coast, A n t a r c t i c a . " Ph.D. D i s s e r t a t i o n , Ohio State U n i v e r s i t y , 222 pp., 1963. Richard L. Cameron- " G l a c i o l o g i c a l Studies a t Wilkes S t a t i o n , Budd Coast, A n t a r c t i c a . " AGU A n t a r c t i c Research Series, No. 2, pp. 1-36, 1964. 834

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