It is evident that if the heat transfer by the sea to the atmosphere occurs with wind, not only 

 will convective but also frictional intermixing take place. This fact makes it possible to enlarge 

 the application of formula (5) also to the case when the sea is colder than the air. Indeed, in this 

 case the heat transfer is materialized by frictional intermixing, though convection is absent. 



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Figure 8 . The change of temperature of the active layer of the atmosphere 

 with the wind moving toward the warmer or the colder sea. 



The curves in figure 8 demonstrate a gradual approach of air temperature to the temperature 

 of the sea surface. The rate of this approach increases with a decrease in the height of the active 

 layer of the atmosphere and with increase in the wind speed. The rate of this approach is greater 

 for a cold wind than for a warm wind. 



For utilization of formulae (4) and (5), it is necessary to know the wind speed, the temper- 

 atures of sea surface and air at the initial point, and coefficient .4 . In order to determine this 

 coefficient, it is necessary to know, (in addition to the temperature of the sea surface and the air 

 at the initial point, and wind speed and direction), the air temperature at at least one point upwind 

 from the initial point. On the basis of formula (4) we have: 



d iu 



-ta 



ia. 



(6) 



where d = the distance to the point, at which the air temperature equals ta, from the point at 

 which the initial temperatures of the sea surface and the air are measured, 



w = wind speed. 



It should be underlined that on the basis of the meaning of the derivation of formula (6) one 

 must assume that temperatures t^ ,tQ and t^j are the mean temperatures of the active layers of 

 the sea and atmosphere. For the use of temperatures of sea surface and the air at the height of the 

 observer, one must assume that the latter temperatures are proportional to the mean temperatures 

 of the active layers. 



In table 14 are shown, for the sake of illustration, the computed results of some of the obser- 

 vations carried out in the White Sea. 



41 



