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MONTEZUMA SOLAR-CONSTANT VALUES AND 

 THEIR PERIODIC SOLAR VARIATIONS 



By C. G. abbot 

 Research Associate, Smithsonian Institution 



We are convinced that solar-constant values from the Mount 

 Montezuma, Chile, station are more accurate than those of any other 

 Smithsonian station. This results from the meteorological superiority 

 of the location. In three recent papers ^ (treating respectively of the 

 6.6456-day period in the solar radiation and in w^eather, of the trig- 

 ger action of depressions of solar radiation to set off West Indian 

 hurricanes, and of the effect of ionic bombardment of the earth to 

 diminish solar radiation received here at times of great sunspot ac- 

 tivity) I used the daily solar-constant values of Montezuma exclu- 

 sively. The inclusion with them of less accurate data from our other 

 stations would have been injurious in these studies of very small 

 solar changes. 



In volumes 5 and 6 of Annals of the Smithsonian Astrophysical 

 Observatory, and in my paper "A Revised Analysis of Solar Con- 

 stant Values" ^ the lo-day and monthly mean solar-constant values 

 from several Smithsonian stations were combined in researches on 

 long periods in solar variation. It seemed advisable to me to make 

 a new search for long solar periodicities, using Montezuma data 

 alone. I wished especially to test my former conclusion that all the 

 periodic variations are integral submultiples of 273 months. 



I have prepared a table of lo-day and monthly mean solar-constant 

 values for Montezuma alone, from September 1923 to December 

 1947. They are given in table i. 



In table i the year and month are given in column i. In column 2 

 appear the lo-day and monthly mean values of the solar constant, 

 from Montezuma observations alone. Column 3 gives the number 

 of days entering into these mean values. Readers should note that 

 values in column 2 are to be understood as prefixed by the figures 1.9 



Smithsonian Misc. Coll, vol. 107, No. 4, 1947; vol. no, Nos. i and 6, 1948. 

 Smithsonian Misc. Coll., vol. 107, No. 10, 1947- 



SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. Ill, NO. 7 



