N = heat carried out of a given basin by sea currents (- pertains to case when the tempera- 

 ture of outgoing waters is higher than the mean temperature of the basin), 



R = the "cold" taken out of a given basin together with ice, 



Q = the "cold" brought into a given basin together with ice. 



It stands to reason that, for individual areas, not all of the terms of the equation of heat balance are 

 of the same order. 



So for instance, in basins with limited water and ice exchange with neighboring basins, the 

 magnitudes M, N , P and Q may be of such small significance that they can be neglected in the first 

 approximation. The White Sea, for instance, is one such basin. In the Chuckchee Sea we can dis- 

 pense with the continental runoff. In the central arctic basin, where the sea is covered by contin- 

 uous ice, the effect of solar radiation, owing to the great albedo of ice, becomes small in compar- 

 ison with other components, etc. 



The equation of heat balance is applicable not only to the year but also to individual seasons . 

 Thus, for the arctic night the equation will assume the following form: 



— r— £+ C + M — N-irP — Q =K, 

 where K = the variation of heat reserves in the basin during the given time interval. 



In the latter equation the solar radiation for winter equals 0, but the heat amount brought in 

 by the continental rimoff in the winter, as we saw, is so insignificant that it can be neglected in the 

 first approximation. 



At the present time, only the first attempts at calculating the heat balance have been made, 

 and they are restricted to individual seas. However, even after the methods of calculating the heat 

 balance have been developed and the pertinent data obtained, the veritication of the calculations will 

 be necessary. 



Assume that hydrological observations are carried out from time to time and stations occu- 

 pied sufficiently often in a given area to arrive at the mean temperature of the basin. 



It is obvious that on the basis of comparisons between the mean temperature values obtained 

 in such a way one can draw conclusions about the variation in the heat content of a given water basin 

 from one time moment to another, which result from the cumulative action of the components of the 

 heat balance . 



K the basin is large and the employment of a dense network of hydrological stations requires 

 too much effort, observations are conducted in directions that are more typical of the basin — i.e. , 

 in the standard oceanological cross sections. 



One of such standard cross sections — along the Kola longitude in the Barents Sea — intersects 

 the Nordkapp current. By measuring the water temperature along the Kola longitude at the same 

 geographical coordinates, we are in fact measuring the temperature of various water masses. 



58 



