10° 30° 



40° 50 



1B° 80° 



100° 110° 



120° 00° 



Figure 152. Depths and Oceanographic Section in the Arctic Basin 

 along the drift track of the Sedov. 



given off by the sea to the atmosphere in the Arctic Basin is made up not only of the heat which is 

 lost by the warm layer. During the course of the summer the ocean here stores up a considerable 

 quantity of heat as a result of the rise in temperature of the ice, melting of a part of its thickness, 

 and some heating of the water between floes and under them. During winter, the heat which has 

 accumulated in the summer returns to the atmosphere. 



Finally, we must recall that huge masses of ice are carried out of the Arctic Basin every 

 year into the more southerly latitudes and mainly into the Greenland Sea. Ice in the sea is actually 

 concentrated cold which has accumulated during the winter. Every gram of ice represents 80 

 calories. If we accept very cautiously the fact that every year there is carried out of the Arctic 

 Basin an area of only one tenth of its whole ice cover, of thickness about 300 cm, or in other words, 

 about 30 cm of ice from the whole area of the Basin, then this likewise amounts to about 3 kg-cal 

 per square cm. 



More remarkable with respect to the warm layer is the fact that in the central part of the 

 basin the temperature of the layer steadily decreases in a northern and eastern direction, but the 

 depth of the maximum remains practically unchanged. Observations made up to this time show the 

 occurrence of such a maximum at a depth of about 400 m. 



If the vertical coefficient of mixing were the same in both the upper and the lower layers, then, 

 since the temperature gradient is greater in the upper layers than in the lower, the depth of the 

 temperature maximum would of course descend with the passage of time. The fact that this maxi- 

 mum remains at approximately the same depth despite the lowering of the temperature of this 

 maximum over the course of time, proves that here an equilibrium is comparatively quickly reached; 

 i.e., the flow of heat directed upwards from the warm layer is equal to the flow of heat directed 

 downwards from this layer. This may be explained only by the fact that, despite the observed 

 difference of temperature gradients, and despite the fact that the gradients of horizontal speed are 



415 



