AVERAGE iVo STRUCTURE 



113 



Figure 4.17. Diurnal, seasonal, and vertical variation of No/or Oakland, Calif. (OAK). 



The interplay of polar and maritime air masses along the middle east 

 coast of the United States is reflected in the strong seasonal range of 50 A^^ 

 units at Washington, D.C. (DCA), figure 4.21. The summertime diurnal 

 range of 15 A" units reflects the moderating influence of maritime air so 

 common along the central east coast in the summer. 



The latitudinally controlled lower mean temperatures of the northeast 

 coastal regions are reflected in the generally lower values of A'^o plus 



