NO. 7 THE ATMOSPHERE AND THE SUN CLAYTON 7 



no values of solar radiation were available, only sun-spot numbers 

 were used and an equivalent value of solar radiation was derived 

 from Abbot's ' plots of equivalent values and placed in parentheses. 



Since both sun-spot numbers and increased solar radiation are 

 considered in forming this table, the results derived from a compari- 

 son of the data in the table with meteorological conditions rest on 



Table 2. — Relative Sun-spot Numbers and A^'erage lvalues of Solar Radiation 



Used in Study 



High solar values Low solar values 



Date Sun-spot Solar Date Sun-spot Solar 



summer number radiation summer number radiation 



Apr. 1916 72 (1.952) Apr. 1912 4 (1.928) 



" I9I8 81 1.953 " I9I3 I (1.925) 



May 1917 114 1-956 May 1910 22 1.916 



" 1920 34 1.953 " 1913 (1.923) 



June 1905 49 1.968 June 1909 23 1.930 



" 1919 Ill 1-955 " 1912 4 1.930 



July 1906 103 1.962 July 1910 14 1. 913 



■' 1917 120 1.989 •' 1911 3 1.917 



.A.ug. 1917 154 1.956 Aug. 1909 23 1.926 



" 1918 102 1.954 " 1910 II 1.912 



Sept. 1917 129 1.948 .Sept. 1909 39 1.908 



" 1918 80 1.944 " 1910 26 1.915 



Mean 95.7 1.958 Mean 8.3 1.917 



Winter Winter 



Oct. 1917 72 1.952 Oct. 191 1 3 1.915 



" 1918 85 1.939 " 1913 3 1.866 



Nov. 1917 96 (1.954) Nov. 1911 4 1.903 



" 1919 42 (1.953) " 1913 I 1.866 



Dec. 1917 129 (1.957) Dec. 1911 2 (1.926) 



" 1920 40 1.955 " 1913 4 (1.928) 



Jan. 1918 96 (1.954) Jan. 191X 3 (1.927) 



" 1920 59 1.964 " 1913 2 (1.925) 



Feb. 1918 65 (1.951) Feb. 1912 o (1.923) 



" 1920 51 1.956 " 1913 3 (1.927) 



Mar. 1917 95 (1.954) Mar. 1912 5 (1.929) 



" 1920 72 1.945 " 1913 o (1.923) 



Mean 75.2 1.955 Mean 2.^ 1.913 



\'alues in parentheses are derived from sun-spot data and are taken from Abbot's curve 

 of equivalent values, Smithsonian Misc. Coll., Vol. 80, No. 2. 



increased solar activity, whether measured by sun spots, faculae and 

 flocculi, or by an increase in solar radiation reaching the earth. 

 Solar radiation values are missing for a number of the spring and 

 winter months because no observations were made during these 

 months in the earlier years. These months are included because it 



' A group of solar changes, Smithsonian. Misc. Coll.. \^ol. 80, No. 2, p. 8. 1927. 



