NO. 7 THE ATMOSPHERE AND THE SUN CLAYTON 9 



land stations, a further selection was made by grouping the stations 

 into areas of 20° of longitude and 10° of latitude and taking means 

 for each group. Finally, the means for the different groups were 

 obtained for each 10° of latitude. The average departures of the 



Table 4. — Mean Departures of Pressure from Normal in Millibars zvith Loiv 



Solar Actiznty 



Winter Half- Year 



Summer Half- Year 



Year 



Values in parentheses arc interpolated from a synoptic chart (polar projection). 



pressure from normal, in millil)ars, with high solar activity are shown 

 in table 3, and the average departures from normal with low solar 

 activity are shown in table 4. 



The means in the last columns of these two tables show clearly 

 that with high solar radiation there is a defect of pressure in the 

 equatorial belt from the Equator to 30° N. latitude, an excess of pres- 



