the drag of the water. Then the ship loses quite a bit of speed. Thus, the velocity of the Fram, 

 which entered the region of dead water off the Taimyr Peninsula on 29 August 1893, dropped from 

 4.5 to 1 knot. 



The concept of mire was established in connection with the development of submarine naviga- 

 tion. Submarines, in regions where a sharp density discontinuity layer is observed, on submerging, 

 balance their bouyancy in such a manner that they sink in the upper layer and ascend in the lower 

 layer. In such a case, the boat may lie on a discontinuity layer without moving as if on a real 

 bottom. 



LITERATURE: 62, 103. 



Section 35. The Distance Transfer of Temperature 

 Anomalies of the Ocean 



As soon as the surface temperature of a certain ocean region deviates from the norm for 

 some reason or another, this anomaly is immediately transferred to the bottom (by mixing) and 

 horizontally (by currents). 



Let us assume that a temperature anomaly is created in the center of a rectangular canal 

 throughout whose cross section there flows a current caused by some force or another. This anom- 

 aly is immediately reflected in the slope of the longitudinal level of the canal. It can be easily seen 

 that with a negative anomaly in the upstream part of the canal the current velocity increases, while 

 in the downstream part of the canal, it decreases. Conversely, with a positive anomaly, the veloc- 

 ity of the current upstream decreases, and the downstream increases. 



Thus, any temperature anomaly inevitably creates an anomaly of the velocity of the current, 

 whereupon if the temperature at any place upstream anomalously Increases, this causes an in- 

 crease in the downstream velocity, and vice versa. 



Let us further assume that we are dealing with a warm current, i.e. , viath one for which the 

 temperature dropped downstream, (e.g. , the Nordkapp, Spitsbergen, and deep Arctic currents) and 

 that for some reason or another the velocity of the current increased in a certain part of it. If we 

 assume that in the time it takes to run from this region to another, the current is cooled propor- 

 tionally to the time of this run, it appears that the temperature downstream should increase even 

 when the temperature does not change upstream. It is evident that for a cold current (the Green- 

 land current) with an increase in the velocity upstream, the temperature of the current downstream 

 drops correspondingly. Thus, temperature changes result in velocity changes, and vice versa. 

 For a warm current, temperature and velocity changes are unidirectional. In first approximation, 

 we may consider that an increase In the temperature of such currents is proportional to an increase 

 in their velocities, and vice versa. The reverse phenomena should be observed in cold currents. 



Let us now assume that in a certain time interval the temperature increases upstream. 

 Accepting the fact that here the current velocity does not change throughout its entire length, as is 

 the case wtih conditions of heat exchange with the atmosphere and the contiguous waters, we find 

 that the temperature increase noted anywhere upstream will consequently be noted in ranges lo- 

 cated further downstream. Thus the propagation rate of a temperature anomaly will be determined 

 by the velocity of the current itself, and sometimes may serve as a reliable means for actually 

 judging the mean velocity of this current. 



84 



