32 



retention of the coastal ice for which that coast is notorious. None 

 of the so-called middle ice usually present in the central portion of 

 Baffin Bay was encountered by the Northland, although the slower 

 and countercurrents found at the deep ends of both sections would 

 favor its retention in the basin. 



Referring again to the velocity profiles for sections A and B the 

 Baffin Land Current is seen as strong in the upper levels with velocities 

 up to 50 centimeters per second (approximately 1 knot) . Its magai- 

 tude diminishes rapidly with increasing depth and does not exceed 1 

 centimeter per second at depths of or exceeding 500 or 600 meters. 

 Strong currents would not be expected at greater depths as free inter- 

 change of deep water with that of other bodies is prevented by the 

 shallow thresholds of the various entrances to Baffin Bay. The deep- 

 est is probably that of 675 meters of the Davis Strait ridge. The 

 offshore ends of both sections show, however, a slow countercurrent 

 setting north, extending to a considerable depth and overrun along 

 its inner edge by the Baffin Land Current. Smith, Soule, and Mosby 

 (loc. cit.) have pointed out that water of relatively high salinity enters 

 Baffin Bay from the Labrador Sea via the West Greenland Current 

 a portion of which crosses the Davis Strait ridge off the Greenland 

 coast. As this water cools in moving north through the basin it would 

 undergo some mixing and cabbeling, eventually sinking to contribute 

 to the deep water and deep water circulation of the basin. This north 

 setting water is characterized by higher temperatures and higher 

 salinities than that of the Baffin Land Current. 



The volume of the West Greenland Current entering Baffin Bay in 

 1928 was 1 million cubic meters per second, but is variable. Soule 

 (Bulletin 28, tliis series) reports 0.12 million cubic meters per second 

 for 1938, and gives 1.13 million cubic meters per second as an average 

 value. Subtracting this latter value from the flow of the Baffin Land 

 Current the net transfer south across the Davis Strait ridge is of the 

 order of 1 million cubic meters per second, which volume must be 

 contributed largely by additions through Smith, Jones, and Lan- 

 caster Sounds in the northern part of the bay. Much of this water 

 contributed from the north, as well as coastal water, both of relatively 

 low temperatures and salinities evidently flows south in the Baffin 

 Land Current and empties across Davis Strait into the Labrador Sea 

 suffering but little mixing en route. 



Figure 21 shows the vertical profiles of temperature and salinity at 

 sections A and B. A thin superfically warmed layer of low salinity 

 water is evident at both sections. The slopes of the curves for the 

 upper levels show the generally lower temperatures and salinities of 

 the inshore Baffin Land Current water as compared to offshore water. 

 The penetration of a core of relatively warm water from the center 

 of the basin occurs in both sections at a depth of about 500 meters. 



