SECT. 2] 



laiu:e-scale interactions 



119 



in some areas of higher latitudes where tlie sea is still free of ice. Under these 

 conditions, turbulent heat Hux can exceed 50 kg cal/cni^ year (or 137 cal/cm^ 

 per day). Fig. 8 suggests that the other warm currents, except the Gulf Stream, 

 exert a relatively minor influence on Qs. 



The cold currents, which lower the sea-water temperature, diminish the 

 turbulent streams of heat from the ocean surface into the atmosphere and 

 reinforce streams of opposite flow. As a result, in some regions affected by cold 

 currents, Qs though small is negative (Canary, California, Benguela Currents). 

 More complicated are the causes for the appearance of areas of negative Qs in 

 the southern portions of the Atlantic and Indian Ocean (at 50°S). In this 

 case, the turbulent flux is apparently affected by the advection of warm air 

 masses over a cold ocean surface. 



Again the main difference between the pattern in Fig. 8 and the similar 

 figure by Jacobs is the relative reduction here in the longitudinal anomalies 

 due to ocean currents, particularly in the Kuroshio, which scarcely shows up in 

 Fig. 8 (see Table IV). The Gulf Stream peak is also reduced, as is that of the 

 Canary current off Africa, where Jacobs shows an isopleth of — 30 cal/cm^ day 

 ( — 10 kg cal/cm2 year) which is absent on Fig. 8. 



B. Mean Annual Distribution of the Remaining Components of Ocean 

 Surface Heat Balance 



The mean annual distribution of total incoming short-wave radiation im- 

 pinging upon the ocean surface, {Q + q) in equation (2), is reproduced from the 

 Atlas of the Heat Balance in Fig. 9. The radiation balance, R, of the ocean 

 surface, arrived at by correcting for albedo and by subtracting back radiation, 

 is shown in Fig. 10 (for details of the formulas and methods, see Budyko, 1956). 



Fig. 9. Mean annual distribution of total radiation {Q + q) impinging on the ocean surface, 

 in kg cal cm~2 per year. (After Budyko, 1956, Fig. 16.) 



