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SIXTEEN-DAY WEATHER FORECASTS FROM 

 SATELLITE OBSERVATIONS 



By C. G. ABBOT 

 Research Associate, Smithsonian Institution 



Measures of the solar constant of radiation are possible from satel- 

 lites. Coursing above the obstructing atmosphere, a suitable pyrheli- 

 ometer could measure the intensity of solar radiation directly, without 

 spectrum observations. Many measurements could be made daily and 

 no days omitted. Though they might not be individually as precise as 

 those of the Smithsonian observers in the years 1924 to 1952, the 

 mean value of a day from satellite measurements would be more pre- 

 cise than they were. It could readily be reduced at the ground from 

 radio-transmission reports. 



Twenty-five years ago I showed that upward and downward trends 

 in solar radiation were followed, for at least 16 days, by trends in 

 terrestrial temperature which were opposite, like the right and left 

 hands. 1 Using identical dates of starting of solar trends, I found that 

 Washington, St. Louis, Helena, Potsdam in Germany, and Ebro in 

 Spain all presented opposite trends of temperature for rising and fall- 

 ing solar changes. Large solar changes produced large temperature 

 variations and vice versa. Thus one perfect set of solar-constant 

 measurements would suffice for 16-day temperature predictions world- 

 wide. Dr. R. A. Millikan, supported by Dr. I. Bowman, Dr. K. T. 

 Compton, and the then Chief of the U. S. Weather Bureau, prepared 

 a recommendation whose text is printed in Smithsonian Publication 

 3397. It suggested that an appropriation of $300,000 be made to en- 

 able the Smithsonian Institution to set up several solar-constant sta- 

 tions at the best sites. These would be additional to the three stations 

 then operative. It was hoped thus to get from their mean results high- 

 grade solar-constant values daily. 



This recommendation was approved by President Roosevelt and the 

 Director of the Bureau of Budget. The appropriation passed the 



1 Smithsonian Misc. Coll., vol. 95, No. 12, Publ. 3392, and vol. 95, No. IS, 

 Publ. 3397. 1936. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 143, NO. 2 



