DAVIS STRAIT AND LABRADOR SEA 



143 



ling the circulation, when, due to solar warming, the presence of the 

 Laorador Current is more or less screened from view. This condition 

 is accentuated in summer as still warmer surface water of the At- 

 lantic Current is spread in toward the Grand Banks' slopes by the 

 prevailing southwesterly winds. 



The seasonal range in minimum temperature of the Labrador Cur- 

 rent in the Grand Banks sector may be wide. Temperatures as low 

 as —1.6° C, have been recorded at a depth of 100 meters, and as 

 high as 2.9° C., at 150 meters along the east side of the Grand 

 Banks in the axis of the cold current. The seasonal range of the 

 temperature of the Labrador Current has been commented upon by 

 Smith (1924, pp. 160-165). 



The minimum wintertime temperatures over the Grand Banks, 

 surface and bottom, are approximately —0.3° C. and —0.8° C, re- 

 spectively. The Grand Banks column at the end of winter is usually 

 in thermal homogeneity except where the Labrador Current has in- 

 ,truded on the bottom. The maximum surface temperature recorded 

 by Smith (1924, p. 148) was 13.2° C., but a summer temperature 

 more commonly attained is 11.0° C. The maximum bottom tempera- 

 ture was approximately 2.0° C., but such relatively high temperatures 

 may often be displaced even during summer by negative-tempera- 

 tured water from the Labrador Current. 



The Grand Banks sector, embracing as it does the discharge of 

 the Labrador Current, subject to wide and rapid fluctuations, even 

 ceasing to flow at times, represents a verj^ poor field to determine 

 the question of an annual cycle. The quantitative data on the 

 Labrador Current, at least up to the present, fail to reveal any 

 annual cycle in its flow. If an annual cycle does exist, it is probably 

 relatively slight, being outweighed by shorter irregular pulsations. 



Volume of Labrador Current and Atla^itic Current in Grand Banks sector 

 Millions of cubic meters per second 



