The observations of the station "North Pole" confirmed by ideas about the presence of a belt 

 of water of relatively high salinity, embracing, at least in the European-Asiatic sector, the central 

 part of the Arctic Basin. Actually, the lowest salinity of arctic surface water appeared near the 

 North Pole and it increased toward the south. In addition, the salinity of arctic surface water in the 

 drift region of the station "North Pole" was less than the salinity at the northern observation points 

 of the Sadko in 1935. 



More striking is a comparison of salinities observed in Chuckchee Sea with salinities in the 

 Arctic Basin in the region to the north of Wrangel Island. In the whole of Chuckchee Sea, including 

 the Berii^ Strait, even in summer the 32 o/oo isohaline does not descend below 30 m. In addition, 

 from the Bering Straits to Wrangel Island there stretches a tongue of water of salinity over 33 o/oo. 

 But to the north of Wrangel Island the level of the 32 o/oo isohaline gradually descends. At 73°30' 

 north, 184°30' east it descends to 40 m and finally, at the oceanographical observation points be- 

 tween 78°27' and 81°32' north, 176''32' and igClC east, it descends to 60 m. 



There is now a complete basis for assuming that in the central part of the Arctic Basin the 

 surface water is not saltnified, but on the contrary is freshened. This remarkable and hitherto 

 unnoticed phenomenon may be explained only by the fact that the summer melting here exceeds the 

 winter freezing. 



For a definitive decision on this question, however, there is needed a more precise analysis 

 of existing observations than I have as yet made. In any case, the stability of the arctic surface 

 water is increased by this freshening thereby hindering the deep diffusion of vertical winter cir- 

 culation with the lower waters. 



How limited this exchange is may be judged by the following: In summer there are very many 

 diatoms in the ice of the Arctic Basin and in the surface water. However, in the bottom deposits of 

 the deep part of the Arctic Basin, according to T.I. Gorshkov, diatoms are not found. 

 LITERATURE: 47, 77, 112, 164, 165. 



Section 147. Atlantic Water 



Althov^h conjectures concerning the entry of Atlantic water into the Arctic Basin had been 

 expressed even before the Fran expedition, Nanson was the first explorer to find this water in the 

 arctic and explain its significance.* 



In the Arctic Basin and its surrounding seas we find water of various temperatures and vari- 

 ous salinities. We have seen that the water exchange of the Arctic Basin with the Pacific Ocean is 

 extremely limited. The water exchange with the Barents Sea is slightly greater, but the main ex- 

 change is with the Greenland Sea. In other words, the entire saline supply of the Arctic Basin is 

 of Atlantic origin. 



♦Refer to the well known report "On Through to the Pole" by Makorov which he wrote in 1897 

 before the publication of the results of Nansen's expedition. 



Having only the temperature observations of the Fram , and expressing regret that there had 

 not been published the specific gravities which would have made it possible to determine immedi- 

 ately the source of the warm stratum which was found, Makarov says: "We may say that the warm 

 water at 200 to 800 m should be more saline than the surface water or otherwise it would rise up- 

 wards and not remain below. Since there are in the Arctic Ocean many reasons for decrease of 

 salinity, it is therefore evident that the water which occurs at the 200 to 800 m layer comes from 

 the southern latitudes." 



410 



