whereby, during the periods characterized by the warming of sea and over cold currents, the air 

 temperature is somewhat higher. During periods characterized by cooling of the sea and over 

 warm currents the air temperature is somewhat below the temperature of sea surface. 



On the basis of 340 simultaneous observations of sea surface temperature and of air tem- 

 peratures (12 m above the sea level), which were carried out during the Sadko expedition in 1935 in 

 Greenland, Barents and Kara Seas, I plotted a graph (figure 7) on the horizontal axis of which are 

 laid off differences between the water and air temperatures, and on the vertical axis the number of 

 observations. In 193 cases the difference fluctuated from -2° to +2°. In 104 cases, the deviation 

 from 0° did not exceed 0.5°. 



too 



80 



< 

 u 



u. 



o 



Oi 

 lU 

 CO 



3 



60 



40- 



20 



r- 



-6 



■10 



-8 



-4-2 2 1 



WATER-AIR TEMP. DIFFERENCE 



10" 



Figure 7. Differences between the water and air temperatures in August and 

 September 1935 in the Barents, Greenland and Kara Seas. 



Cases when the air was considerably warmer than the water occurred when navigating along 



the coast during offshore winds. Thus, the difference t^ 



*a= -9° 



was observed 15 miles to the 



north of Nordkapp. Cases when the air was considerably colder than the water occurred when nav- 

 igating along the edge of concentrated ice during winds blowing from the direction of the ice . 



These examples characterize with sufficient clarity the effect exercised by the temperature 

 of sea surface on the temperature of the contiguous air strata, the effect being felt in brief inter- 

 vals and at small distances from areas where the temperature difference is great. This circum- 

 stance, as well as the fact that the sea temperature remains almost unchanged during these brief 

 time intervals (which is explained by a great difference between the heat capacity of the air and 

 that of the water) enables us, despite all the complicity of the problem, to arrive at approximate 

 solutions that characterize the gradual change of air temperature over the sea. 



Assume that the sea is warmer than the air and that the temperature of the sea surface changes 

 so little during a given time interval that it can, to a first approximation, be considered as constant. 



The quantity of heat transferred through area F in time dT by the sea to the atmosphere equals 



dQ=F{t^,—ta)kdT, 



(1) 



39 



