302 



the accelerating pace of technological achievement was generating a 

 need for more frequent international efforts. By 1950, at least three 

 compelling reasons for reducing the time interval between "polar 

 years" had evolved: (1) existing basic scientific data in the earth 

 sciences had been largely exploited, making desirable the accumulation 

 of new data; (2) the need for new information regarding the earth, 

 the oceans, and the upper atmosphere was becoming critical with the 

 development of supersonic aircraft and new communications systems; 

 and (3) a period of unusual solar activity was predicted for 1957- 

 58, thereby offering an unparalleled opportunity for observing solar 

 phenomena. 



IMPETUS FOB A THIRD INTERNATIONAL POLAR TEAR 



It was therefore suggested by Berkner that a Third International 

 Polar Year (TPY) be held during 1957-1958, only 25 years after the 

 SPY, rather than the anticipated 50 years. The suggestion, which was 

 made at a small gathering of scientists at the home of Dr. James A. 

 Van Allen, was enthusiastically welcomed by Van Allen and his guests, 

 who suggested that Berkner should present his idea at the next meet- 

 ing of the Joint Commission on the Ionosphere (MCI). 23 Following 

 this suggestion, the basic concept of the TPY was presented to a num- 

 ber of international scientific organizations which readily supported 

 and promoted the idea. A schematic representation of the progress 

 of the concept through the world scientific community is given in 

 figure 1. Initially, as suggested at the Van Allen meeting, Berkner 

 and Dr. Sydney Chapman, who later was to serve as president of the 

 governing IGY committee, presented the concept at the Brussels 

 meeting of the MCI in July 1950. The MCI endorsed the proposal, 

 amplified the suggested program somewhat, and recommended the 

 proiect to the International Council of Scientific Unions (ICSU), 

 and the three groups comprising ICSU: the International Union of 

 Scientific Radio (URSI), 23 the International Union of Geodesy and 

 Geophysics (IUGG), and the International Astronomical Union 

 (IA U) . The URSI and IAU officially endorsed the plan in September 



1950, and the IUGG followed with its endorsement in August 1951. 

 The ICSU Bureau, the executive body responsible for operations of 

 IC^U^approved the plan in January 1951 and recommended it to 

 the ICSU executive board, which granted its approval in October 



1951. On May 16, 1952, the ICSU established a committee to take 

 •charge of the program, which was still being considered primarily 

 as a Third Polar Year. 



M 8ometlmes referred to as the Mixed Commission on the Ionosphere. 



* The Initials are derived from the French version of its name: the Union Radlo-Scientiflque Internation- 

 ale. 



