The great difference in the salinities determined by Weyprecht and those determined by 

 Malmgren is only partially explained by the fact that Weyprecht's sample was formed in more sa- 

 line water and at a much lower air temperature. The main reason is that Weyprecht investigated 

 his ice floe only 60 hours after it started to form, while Malmgren made his investigations in 

 April on ice which had begun to form in November. 



As Libin informed me, according to the investigations of the expedition, by airplane N-169, 

 of an ice field (79°54' north, 140° east on 28 April 1941) 210 cm thick, which was one and a half 

 years old, the layer salinity (computed with respect from the chlorine content) was as follows 

 (table 32): 



TABLE 32. THE VERTICAL DISTRIBUTION OF SALINITY IN OLD ICE 

 The layer from the surface of the field in cm . . 20 40 60 80 100 



The salinity in o/oo 0.19 0.21 0.28 0.46 0.88 0.99 



From these data, it can be seen how extensively the upper ice layers are desalted in the 

 course of time. 



5. The height of the ice above sea level. The higher the ice rises above the sea surface, 

 the fresher it becomes, which is explained by brine seepage. Therefore, the upper part of the 

 ropaki and the hummocks are almost always fresh, and, in addition, they are desalted extremely 

 rapidly, especially during the summer.* 



During recent years, many determinations of the salinity of fast ice were made at Soviet 

 polar stations. Chernigovskii presents the following interesting data: The salinity of the upper 1.5 

 cm of ice which had formed on 30 December 1931, in Matochkin Shar when the temperature was 

 39.9° below zero, was 24. 1 o/oo. The maximum salinity of young ice observed in 1934 - 35 on 

 Franz Joseph Land was 25.02 o/oo. 



The changes of salinity at all ice levels is not great during the winter at the Kara Sea 

 stations. By the end of April, a decrease in the salinity of the upper ice layers begins. This de- 

 crease becomes especially great when there is an increase in solar radiation and when the air 

 temperatures are positive. During this, ice desalting takes place from the ice surface down to 

 100 cm. However, at the 120 to 160 cm level, at the same time, the salinity also increases 

 somewhat. 



LITERATURE: 52, 62, 104, 166, 177. 



Section 56. Surface Brine and Salt Cell Brine 



It has already been pointed out that the salinity of sea ice is determined by surface brine and 

 the brine in salt cells. 



Surface brine is formed from frozen sea water which is left on the ice formations that have 

 floated up to the sea surface, and from the brine which is forced out of salt cells and upward when 

 their temperature decreases and the corresponding formation of ice layers in them. 



♦During the F. F. Bellingshausen Antarctic Expedition on the ships Vostok and Mirny i 

 (1818 to 1821), chunks of sea ice were hoisted on deck to obtain fresh water. The ice somewhat 

 melts, sea water runs off, and the ice becomes fresh. 



141 



