254 



[chap. 4 



In the regions of the warm waters of the Gulf Stream and Kuroshio, evapora- 

 tion is as high as in the tropics and sensible heat fiux becomes the dominant 

 term in the energy budget of both sea and air ! Here the ocean gives back the 

 warmth it has acquired under tropical and summer suns to wintry air-masses 

 pouring over it off frozen ground. As implied, these fluxes are by no means 

 steady, but occur spasmodically when the large-scale flow pattern is such that 

 strong northwesterly winds bring the cold dry air rapidly over the warm coastal 

 waters, usually in the outbursts following cold front passage. Manabe (1957) 

 has studied the fluxes in a strong outbreak over the Japan Sea and contrasted 

 it with the average situation there in winter. 



a. A cold-air outbreak over the Japan Sea during the winter monsoon 



Manabe selected for study a particularly intense cold air outbreak which 

 occurred between 20 December, 1954, and 3 January, 1955. During this time, 

 the average sea-air temperature difference exceeded 10 C, so that it will be 

 especially interesting to contrast the energy budgets and exchange relation- 

 ships with the tropical situations described earlier, particularly as the methods 

 of investigation are very similar. Fig. 72 shows that, like the Caribbean ellipse, 



130° 



140° 



-40° 



Fig. 72. Framework for budget study of Japan Sea region, showing meteorological observa- 

 tion stations. Superposed are the mean streamlines of air arriving at Wajima (Jaj)an) 

 at each standard level up to 700 mb for period studied, namely 20 December, 1954, to 

 3 January, 1955. (After Manabe, 1957, Fig. 1.) 



