1912. Xo. 12. 



THE SEA WEST OF SPITSBERGEN. 



19 



The precipitation has naturally a considerable reducing effect upon 

 the salinity of the surface-layers in these northern regions, as already 

 mentioned. This reduction becomes less conspicuous in the winter, when 

 the vertical circulation helps to intermix the surface-layers with the under- 

 lying strata, a process which goes on far less actively in the summer, when 

 the heating of the sea-surface prevents it. 



Annua/ J\inatious in the Salinity. 



Although there are evidently great variations in the temperature of 

 the Spitsbergen Atlantic Current from one year to another, as will be 

 mentioned later, we have not been able to find an}- similar variations in 

 the salinity of the current, in those few years, from which there are 

 trustworthy determinations of salinity. It has been already mentioned 

 that the salinities of Isachsen's Section I of June, 1910, bear a great 

 resemblance to those of Hjort's Section westward from Bear Island, of 

 September, 1900. The lower salinities of Isachsen's Section I, may be 

 due to the more northerly situation of the section, and do not indicate 

 any appreciable difference in the salinity of the current in the two years, 

 although the dift'erence in temperature was considerable (see later). If the 

 salinity had varied as the temperature, one might have expected higJier 

 salinities in 1910 than in 1900. 



In 1901 Dr. Hjort made a cruise with the Michael Sars to Spitsbergen 

 and took the followinsr vertical series of observations : 



