45 



course of the zero anomaly line. This is the heavy line in figure 30. 

 Thus it will be seen that in 1936 the April survey showed greater than 

 normal intrusion of Atlantic Current water, with May and Jane not 

 much different than normal. It is also possible that the early season 

 departure from normal was the result of the above-mentioned pre- 

 ponderance of the West Greenland Current component in the make-up 

 of the Labrador Current through alteration of the Baffin Land Current 

 character. 



The usefulness of such a method of comparing the results of any 

 survey with average conditions is not impaired by any doubt as to the 

 validity of the T-S relationship used as a reference. Such a doubt 

 does exist and possibly the resulting anomaly maximum is more ap- 

 parent then real. The T-S relation used as a reference below 4° C. 

 has in it a hump of lower saUnity centered at about 3° to 4° C. A 

 smoother curve would require a maximum increase of about 0.02%o 

 saUnity at about 3.5° C. Such an amount would reduce but not 

 erase the anomaly maximum referred to above. This anomaly maxi- 

 mum, coming as it does in depths of about 800 meters, falls within the 

 temperature range of about 3° to 4° C. 



In the area from which the T-S relationship in question was derived, 

 namely from Chesapeake Bay to Bermuda, the temperature range of 

 3° to 4° C. is at a depth of about 1,600 to 3,000 meters. The sugges- 

 tion is that this water has, as one of its components, water from some 

 region where a less positive (or more negative) salinity anomaly is 

 characteristic such as the bottom water of the Labrador Sea. The 

 drainage of such water out of the Labrador Sea into the Western 

 Atlantic Basin is discussed farther on under the heading "Bottom 



temperature." 



POST-SEASON CRUISE, 1935 



As described in United States Coast Guard Bulletin No. 25, a post- 

 season cruise was made in 1935 to the region of the Labrador Sea from 

 about the fiftieth parallel to a Une between Cape Farewell, Greenland, 

 and South Wolf Island, Labrador. The station table data, the result- 

 ing dynamic topographic map of the surface with respect to the 1,500 

 decibar surface, and a bathymetric map of the area covered have 

 already been published in that bulletin. Parts of the data have been 

 drawn upon in the preparation of Bulletin No. 19, Part 2. Some 

 phases of the survey, however, have been mentioned but briefly and 

 will be taken up here. 



Horizontal distribution of temperature and salinity. — The horizontal 

 distribution of temperatm'e and salinity in the upper layers has been 

 illustrated by composite maps of those variables at 100 meters, pub- 

 lished as figures 127 and 128 of Bulletin No. 19, Part 2. At this level 

 both temperature and salinity show the presence of the major surface 

 streams, the Irminger and Atlantic Currents being characterized by 



