3. Rise in temperature of Atlantic water which enters the Arctic Basin. This rise is most 

 clearly seen in existent systematic observations along the meridian of Kola (33°30' east). Taking 

 the average temperatures of this section at depths of to 200 m from 69°30' north to 72°20' north, 

 and dividing existing observations into two periods, cold (1900 to 1906) and warm (starting with 

 1921), I have obtained a rise of average temperatures for May and August of about 0.7°. From this 

 it follows that on the average a column of water of the Norwegian current 1 square cm in section 

 and 200 m high has 14,000 g-cal more heat supply at the present time than at the start of the 

 present century. 



The warming of Atlantic water in the arctic is likewise seen in the following condition: in the 

 regions adjacent to Spitzbergen and Franz Joseph Land there has recently been observed a rise of 

 the lower boundary of the cold Intermediate water layer from a depth of 150 to 200 m, as observed 

 at the start of the present century, to a depth of 75 to 100 m in the present period. 



The warming of Atlantic water is still more sharply seen by comparing temperature obser- 

 vations at the deep water observation stations which the Fram and Sedou made at almost the same 

 geographical points. Figure 195 shows the vertical distribution of temperatures at two of such 

 points from which may be seen the extent of the warming of Atlantic water during the past 40 years. 

 At none of the observation stations of the Fram in the Arctic basin did the temperatures of deep 

 Atlantic water exceed 1.13°. On the Sadko in 1935 we observed a temperature of Atlantic water of 

 2.68°, while according to observations of the Sedou in 1938, temperatures of Atlantic water even 

 in regions North and east of the Fram drift (i.e. , where it should have colder) were up to 1.8°. 



Table 120, borrowed from Shokalski, shows the average yearly temperatures of surface water 

 in the Florida current (in the region bounded by 25° to 30° north and 79° to 80° west) in Yucatan 

 Strait (in the region bounded by 21° to 23° north and 84° to 87° west) and in the Gulf of Mexico (in 

 the region bounded by 21° to 25° north and 90° to 94° west). 



From the table it may be seen that the temperature of surface water and of Gulf Stream water 

 has steadily risen starting with the first decade of the present century. 



A rise in temperature of surface water has likewise been noted in other ocean regions which 

 are under the influence of the Gulf Stream and the North Atlantic Drift, as may be seen from table 

 121 (likewise taken from Shokalski). 



4. Decrease in ice abundance. We may judge about the decrease in ice abundance in the 

 Greenland and Barents Seas from the ice maps of the Danish Meteorological Institute. According to 

 Karelin's reckoning, the ice area in the Greenland Sea in April to August for the period 1921 to 

 1938 is 15 to 20 per cent less than for the period 1898 to 1920. From my calculations, the ice 

 abundance in the Barents Sea for the same months from 1920 to 1933 was 12 per cent less than for 

 the period 1900 to 1919. 



It must be remembered that the ice in the Barents Sea is mainly of local origin. A decrease 

 in its quantity is connected with a rise of temperature and speed of the Norwegian current. 



Vize shows that the southern part of the Kara Sea (south of the parallel of Matochkin Shar), 

 from the year 1929 has been free of ice in September of every year while for the period 1869 to 1928 

 the probability of finding ice in this part of the sea in the first half of September was about 30 per 

 cent. 



472 



