the year, since December is precisely the time when the north winds along the east coast of Green- 

 land are noted for their special force and constancy. Thus, the annual outflow of ice from the 

 Arctic Basin into Greenland Sea can hardly exceed 2,500 cubic km per year. 



UTERATURE: 16, 62, 71, 77, 112, 118. 



Section 145. Coastal Siberian Waters 



Coastal Siberian waters is the term conventionally employed for the waters of low salinity 

 formed mainly by the mixing of the coastal drainage water of Siberia with the water of oceanic ori- 

 gin which enters the Siberian coastal seas from the adjacent parts of the World Ocean. 



In order to define the limits of this water we must first of all establish the upper limit of its 

 salinity. Obviously, any limitation will be more or less arbitrary. I am personally inclined to 

 accept a salinity of 25 o/oo for this limit. There is some basis for such a choice in the fact that, 

 as we have seen, the freezing point of water of salinity less than 24. 7 o/oo (as with fresh water) 

 is lower than the temperature of greatest density. 



The distribution of the coastal Siberian waters is extremely typical. If we exclude the lower 

 end of Baidaratskaya Bay and the delta areas of the small rivers which empty into the Kara Sea, 

 where extremely low salinities may be found, then the main region of the coastal Siberial waters in 

 the Kara Sea is the region bordered (in the summer) by approximately the 76th parallel on the north 

 and the 73rd on the south. Its western boundary is the east coast of the northern island of Novaya 

 Zemlya, the eastern boundaiy is the mainland coast from Yamal to the 95th meridian. The total 

 area of this water is about 250,000 square km and the thickness of the layer, as a rule, is not over 

 15 m. The annual river drainage into this area covers it with a layer about 6.3 m deep. 



In the Laptev and East Siberian Seas the 25 o/oo isohallne stretches from the east coast of 

 the Tamiyr Peninsula to the east approximately along the 76th parallel, goes around the New 

 Siberian Islands on the north and then descends towards Chaunskaya Bay, thus embracing an area 

 of approximately 650,000 square km. Here also, as a rule, a salinity of 25 o/oo is not found 

 deeper than 15 m. The annual river drainage onto this area covers it with a layer about 1.5 m 

 deep. 



In the Chuckchee Sea a salinity of less than 25 o/oo may be found only near the shore and, 

 therefore, the coastal Siberian waters do not play a large role. 



Thus, the coastal Siberian waters are mainly concentrated in two regions — the Kara Sea and 

 New Siberian Islands regions, although they move to a considerable distance (200 to 300 km) from 

 the main areas of their creation (mouths of the Ob , Yenisei and Lena Rivers) . They flow out in a 

 sort of thin layer along the sea's surface. In shallow depths they extend down to the sea bottom. 

 Over great depths, at their lower surface there is created a sharply defined layer of change of 

 salinity, which in the summer season delimits the depth of dispersion of wind-caused mixing and in 

 winter the depth of dispersion of vertical winter circulation. In connection with all the above-noted 

 facts, the coastal Siberian waters display curious peculiarities in their thermal and saline 

 conditions . 



We have seen that the main heat-containing water masses of coastal drainage of the Siberian 

 rivers empty into the sea during the shore polar summer. This facilitates the break-up and de- 

 struction of the ice cover in the delta regions and the formation of the delta polynyas. The con- 

 stantly observed Ob-Yenisei polynya, for example, is of such origin. The water of these polynyas 



403 



