1 36 The Three-dimensional Temperature Distribution and its Variation in Time 



The cold intermediate layer is particularly pronounced and lasts longest at the 

 edge of pack ice and polar ice. Table 60 presents several examples. Figure 58 shows the 

 temperature along a longitudinal cross-section through the northern Barents Sea 

 74°-77° N., ]9°-38° E.) along the pack ice Hmit in August 1927 according to series 

 observations made by the "Poseideon" (Schulz and Wulf, 1929). From west to east 

 exists a layer of increasing thickness of cold winter water at a depth between 20- 

 1 00 m, while above this there is a layer heated by solar radiation, partly also melt 

 water. With distance from the ice limit this cold intermediate layer weakens and is 

 gradually eliminated by mixing. This cold intermediate layer forms the core of the 

 cold ice carrying currents around Greenland, in Baffin Bay and in the Labrador cur- 

 rent (Defant, 1936). 



200 



240 



St90 



74°0'N 



I9°0'E 



St 15 St8283 St52 53 St50 49 



75°I3'NI 76°I5'N 76°32'N 77°I6'N 

 26°0'E 30°0'E 33°30'E 38°0' E 



Fig. 



58. Longitudinal temperature section in the northern Barents Sea 

 19°-38' E.) along the drift-ice limit (August 1927). 



(74°-77° N. 



The thermal structure of the Polar Sea in the layer beneath the top layer, in con- 

 trast to the cold intermediate layer, is determined by the deep circulation of the polar 

 water. In the European North Polar Basin between 250 m and 750 m underneath the 

 cold top layer, a relatively warm intermediate layer of water of Atlantic origin is 

 introduced with a temperature of about 0-5 °C (maximum of 2-0°C). Its salinity, 

 34-94-34-96%o, shows its Atlantic origin clearly. Underneath this layer spreads cold 

 deep and bottom water that reaches its lowest temperature of — 0-83°C to — 0-87°C 

 between 2000 m and 3000 m (WiJST, 1941, 1942). In high latitudes of the Southern 

 Hemisphere there is generally a similar vertical temperature distribution in all the 

 oceans as shown in Table 61. 



Some numerical values were given previously for the annual heat exchange in ad- 

 jacent seas and in more or less enclosed parts of the ocean (see p. 116). The method 

 used for this can also be applied, as mentioned on p. 98, to the special case of the 



