SECT. 3] 



EASTERN BOUNDARY CURRENTS 



269 



most intense up welling, surface temperatures will be lower than normal for 

 that latitude. At the same time the annual variation of net incoming solar 

 energy increases from the equator toward higher latitudes (Haurwitz and 

 Austin, 1944). Thus, at mid-latitudes a summer maximum of upwelling will 



160° 140° 120 



160° 140° 120° 100' 



Fig. 13. Average yearly variations of surface 

 temperature (°C). (Pacific adapted from 

 Schott, 1935, and Meteorological Office, 

 1956; Atlantic adapted from Bohnecke, 

 1936.) 



20° 0° 20° 40° 60' 



tend to suppress the annual range of surface temperature, whereas a winter 

 maximum will tend to increase this range, relative to comparable latitudes 

 farther offshore. At low latitudes a pronounced seasonal change in the intensity 

 of upwelling will tend to increase an otherwise small annual range of surface 

 temperature. 



In examination of the annual range of surface temperature the following 

 sources were inspected: Atlantic Ocean, Bohnecke (1936); Pacific Ocean, 

 Meteorological Office (1956) and Reid, Roden and Wyllie (1958); Indian 

 Ocean, Koninklijk Nederlands Meteorologisch Instituut (1952) and Schott 

 (1935). The important features are summarized in Fig. 13 and Table II. It is 



