14 BJØRN HELLAND-HANSEN AND FRIDTJOF NANSEN. M.-N. Kl. 



Capt. Isachsen's Spitsbergen Expedition of 1910 gives for the first 

 time a series of vertical sections across the Spitsbergen Atlantic Current, 

 by which the vertical and horizontal distribution of the salinity, determined 

 by modern accurate methods, as also the distribution of temperature, can 

 be studied in detail. 



Our sections I — VIII (Pis. IV to VI) give therefore a very good repre- 

 sentation of the course and extent of this current from the sea northwest 

 of Bear Island, northward along the west coast of Spitsbergen. 



The Salinity of the Spitsbergen Atlantic Current. 



Our sections demonstrate the decrease in the volume of the Atlantic 

 water with salinities above 35.0 '^'00 during its northward course. In Sect. I 

 and II this water has a fairly wide distribution. It is apparently much 

 wider in Sect. I than in Sect. II, but it should be observed that the former 

 section runs obliquely to the direction of the current. In Sect. IV, which 

 runs parallel to Sect. II, the area of the water with salinity above 35.0 ^'qq 

 is smaller, and in Sect. VI onl}' a small volume is left; in the latter section 

 there may have been rather more near the continental slope, as in Sect. MI; 

 but in Sect. VIII there are only some few traces of it. 



It is evident that during its northward course this Atlantic water 

 is being intermixed with less saline water from the sides. Between the 

 Atlantic water and the Spitsbergen coast in Sect. Ill there is a consider- 

 able volume of water with salinities below 35.0 ^ 00 and even below 

 34.9 0/00, and with comparatively low temperatures. This is evidently 

 coast water and to a great extent polar water which has come from 

 the east round South Cape of Spitsbergen with the Spitsbergen Polar 

 Current. This water is probably being gradually intermixed with the Atlantic 

 water on its way northwards along the coast. The effect of this inter- 

 mixture ma}' perhaps be traced in the Sections III, IV, and VI, the volume 

 ot water with salinity less than 34.9 %o gradually decreasing northwards, 

 while the volume of the water with salinity between 35.0 and 34.9 " 00 is 

 on the whole increasing. 



A similar intermixture with less saline water also takes place on the 

 outer side of the Atlantic Current, and on its under side with the under- 

 lying colder water. The precipitation during the whole year naturally 

 produces an appreciable reduction of the salinity of the sea-water in this 

 region where the evaporation from the surface is so small. The 

 vertical circulation created by the cooling of the sea surface during the 

 winter, helps the vertical intermixture of the strata to a great extent. The 

 melting of ice during the summer naturally lowers the salinity of the 



