NO. 3 EFFECT OF SOLAR RADIATION CLAYTON I3 



The areas of positive correlation are colored red, and the negative 

 white. These show very clearly the arrangement of the positive 

 tropical belt widening over the land, and contracting" over the ocean 

 (possibly disappearing), and the belt of negative correlation in the 

 temperate zone widening over the oceans and contracting over the 

 land. Beyond this is a belt of positive correlation near the Arctic 

 circle widening out near the east coast of the continent where the 

 distribution of pressure over the oceans gives rise to winds with a 

 component of motion from the equator. 



Next the pressure correlations were plotted for the third day 

 following- the solar changes (see chart 2). 



On this chart are plotted the belts of high and low pressure of the 

 earth as shown on the charts of Buchan for October, this month being 

 near the middle of the period covered by the observations. The 

 region where the mean pressure is below 760 mm. is colored white, 

 and that above is colored red. It is seen that in every case except one, 

 the correlation is negative in the belts of low pressure of the world. 

 In other words, the efifect of an increase of solar radiation is to 

 intensify these belts. It will be noted also how closely the belts of 

 positive and negative temperature correlations correspond in a re- 

 verse sense to that of pressure, indicating that the pressure changes 

 which have a smaller correlation factor are the result of the tempera- 

 ture changes induced in the air by variation of solar radiation. It 

 is known that the pressure belts vary with the seasons, and it is prob- 

 able that the efifect of solar changes dififers with the season in the 

 various parts of the earth. For example, in the central United States 

 the pressure is low in early summer with an excess of southerly winds, 

 while in winter it is high with an excess of northerly winds in the 

 same region. It is hence conceivable that the same change in solar 

 radiation might have an opposite efifect in the two seasons, showing 

 a positive correlation in the one and a negative in the other. 



COMPARISON OF INDIVIDUAL MAXIMA OF SOLAR RADIATION 

 WITH TEMPERATURE IN VARIOUS PARTS OF THE WORLD 



In studying the variations of temperature in detail as compared 

 with the variations of solar radiation, it becomes very apparent that 

 the efifect of the solar change does vary from negative to positive at 

 the same place, and while there may be a seasonal change there are 

 also changes which cannot be explained in this way, and the reason 

 for which remains yet to be found. 



