All stations occupied during; the tiiree 1941 sur\e>s of the (".rand 

 liaiiks re.uion ha\e been examined for their teniper.iture-sahnitx rela- 

 tionship and mean T-S curves have been drawn for Labrador (\irrent 

 water, mixed water, and water in the border of the Atlantic (\irrent. 

 These curves are shown in figure 11 along with similar curves repre- 

 senting the mean of all observations made during the 8-year period. 

 1934-41. In this figure, the temperature-salinit>' correlations for 1941 

 are shown as solid lines and those for the 8-year period are shown as 

 broken lines. An approximate depth scale in meters is shown on each 

 of the curves. As was the case in 1940, in 1941 both the Labrador Cur- 

 rent water and the mixed water w^ere warmer than normal in the 

 upper levels where the salinity was below 34.9°/oo, and at the deeper 

 levels all three types of water were fresher than normal. 



It will be noticed that shifts in depth are not consistent at all levels 

 and to facilitate examination of the results for indications of long-range 

 trends, figure 12 has been prepared. In this figure the average tem- 

 perature of the Labrador Current in the Grand Banks region has been 

 plotted against its average salinity for each of the years 1934-41 for 

 each of eight levels distributed from the surface to 1,000 meters. At 

 depths of 100 and 200 meters there seems to have been a long-range 

 trend away from Labrador Current characteristics toward Atlantic 

 water characteristics; that is, becoming warmer and saltier. This trend 

 is barely evident at 50 meters and is not discernible at the surface or 

 at depths of 400 meters and deeper. The trend, therefore, seems to be 

 divorced from possible local effects and vertical mixing to which it might 

 be attributed if it had its greatest amplitude at the surface. Instead, it 

 appears to be greatest at about the same depth as the core of mini- 

 mum temperature. Possible causes of such a trend are: (1) A greater 

 admixture of Atlantic Current water or mixed water in the Grand 

 Banks region; (2) an increasing West Greenland Current component 

 crossing the Labrador Sea south of Davis Strait ridge; (3) a change in 

 the heat balance in the Labrador Sea or Baf^n Bay; and (4) a decrease 

 in the circulation in Bafiin Ba\-. 



Considering possible causes (1) and (2), it might be expected that 

 the efTect would extend to deeper levels. Also if possible cause (2) were 

 operative it might be expected that the West Greenland Current passing 

 the Cape Farewell section might show^ a trend toward increasing volume 

 of flow. This, indeed, seems to be borne out by the measurements at that 

 section over the period from 1928 to 1941, although for the 8-year period 

 involved in figure 12 such a trend is not apparent. It is difficult to test 

 whether or not possible cause (3) has been operative. However, the 

 fact that for the last 2 years the intermediate water of the Labrador 

 Sea has been warmer than usual during the summer season, coupled 

 with less pronounced temperature inversion, make possible cause (3) 

 more probable than (1) and (2). The temperature inversion found in 

 the intermediate water of the Labrador Sea in summer has been con- 



13 



