NO. 3 SOLAR RADIATION AND THE WEATHER — CLAYTON 4/ 



heated matter near the center would be less effective, because under 

 normal conditions the radiation from the lower heated matter near 

 the center of the sun is less intercepted and absorbed by the upper 

 layers. 



This view appears to be confirmed by the research of Henrik 

 Arctowski, who has found that the greatest magnetic disturbances at 

 Greenwich and rainfall at Batavia occur when the solar activity as 

 indicated by spottedness, is at a distance of a half-radius or more 

 from the center of the sun (Monthly Weather Review, Nov., 1917, 

 Vol. 45, pp. 538 to 539). 



Ellsworth Huntington also finds that the eft"ect of solar influence 

 on storminess in the North Atlantic is greatest when solar activity, 

 as indicated b)^ sun spots, is greatest on the edges of the sun east and 

 west of the center (Monthly Weather Review, March, April, and 

 June, 1918, Vol. 46, see especially figure 12, p. 174, April, 1918). 



If this view is true, it implies that outbreaks at solar latitudes 

 exceeding 30° would be more effective than between 30° latitude 

 ;md the equator. 



This condition appears to be indicated by the longer periods asso- 

 ciated with the greatest values of solar radiation, because longer 

 periods imply slower solar rotation such as is found in higher 

 latitudes. 



7. For nearly a year, numerical and graphical analyses like those 

 shown in figure 5 have been made of the solar variations and of the 

 variations of temperature at 20 selected stations well distributed over 

 Argentina, Chile, and Brazil. This analysis shows that each varia- 

 tion in solar radiation has been followed by sirnilar variations of tem- 

 perature in South America, with a few exceptions which may easily 

 have resulted from errors in the measurements of solar radiation. 

 These waves are in general most accentuated at the southern stations 

 and in Central Brazil; furthermore, their forms and intensities are 

 modified by local causes ; but the closeness of their connection with 

 the solar waves seems as evident at the other stations as at Buenos 

 Aires, except for different intensities and dift'erent intervals of lag, 

 the waves being in general somewhat later at the northern stations of 

 Argentina than at the southern. But in this respect there appears to be 

 a difference between the longer and the shorter waves. 



The research previously mentioned (Smithsonian Misc. Coll., Vol. 

 68, No. 3), in which were used the temperatures of 1913 for stations 

 scattered all over the world, indicates that this relation of tempera- 

 ture to solar radiation is generally true. At Buenos Aires, the ratio 



