DAVIS STRAIT AND LABRADOR SEA 69 



dynamic topograi^hic map of Baffin Bay (fig. 126, p. 170) indicates 

 that many of the Disko Bay icebergs are carried northward with the 

 current through the Vaigat. Once outside the coastal estuaries and 

 headlands, as indicated by the slope currents (fig. 126), the icebergs 

 follow a generally cyclonic circuit of Baffin Bay. There is no evi- 

 dence from the dynamic topographic maps that icebergs in the south- 

 ern part of Baffin Bay drift directly across to the Baffin Land Cur- 

 rent, The Marion on her track between Disko Island and Cape Dier 

 sighted no icebergs out in the central part of Davis Strait. 



CROSS SECTIONS OF THE CURRENTS 



The stations shown on figure 38 have been grouped into a total 

 of five cross sections of the currents in the Davis Strait sector as 

 shown on figure 40. All of the velocity profiles with little exception 

 emphasize the main features of the circulation described in the 

 horizontal projections. The Baffin Land Current with velocity lines 

 ranging from 5 to 20 centimeters per second in the heart of the 

 current appears on all the profiles, filling the western half of Davis 

 Strait. The West Greenland Current, much weaker, with velocity 

 lines varying from 1 to 5 centimeters per second, prevailed in the 

 eastern half of the strait. A band of northbound Greenland coastal 

 current is also to be noted in each one of the profiles. The southerly 

 current, which appears at stations 161 to 159 on profile 4, and sta- 

 tions 1014 to 1013, profile 5 (fig. 40), refers to the discharge from 

 Disko Bay which the plane of the section intersected at an acute 

 angle. The successive areas of alternate northerly and southerly 

 current recorded on the right side of profile 5 (fig. 40) probably 

 refer to a single band of winding current which followed the ti-end 

 of Disko Island Bank. 



The dynamic gradient resulting from the warmer and fresher 

 waters in over the Greenland banks accounts for the northerly 

 movement of the surface layers * on the east side of Davis Strait. 

 It is quite certain after studying the distribution of temperature 

 and salinity across Davis Strait (see fig. 44) that the same dynamic 

 factors extend down over the edge of the Greenland slope and re- 

 sult in northerly motion of the deeper water there. The higher 

 temperature and salinity of the band of current centered at 500 

 meters on the Greenland slope (see fig. 40, profiles 1, 2, and 5) has 

 already been identified as Irminger-Atlantic portions of the West 

 Greenland Current. Previous published statements have pointed out 

 that this warm water is forced up over the Davis Strait Ridge as 

 an undercurrent to Baffin Bay. The impression of an undercurrent 

 has probably been much accentuated by the behavior of the Baffin 

 Land Current, which, being the more vigorous and lighter, often 

 floods eastward in the surface layers, overriding the West Green- 

 land Current. This appears to be the most logical explanation at 

 present for the position of the currents depicted in profile 1 (fig. 40), 

 and also for the notion that Atlantic water penetrates northward 

 into Baffin Bay as an undercurrent only. 



* Nielsen (1928) identified surface water in Disko Bay which had been encountered 

 earlier in a wide area over Great Hellefiske Bank more than a hundred miles south- 

 ward. 



