132 



flowing branch of the West Greenhmd Current is augmented by the 

 Baffin Land Current flowing southward across the western side of 

 Davis Strait Ridge. This is a verification of the scheme of circulation 

 in the Labrador Basin proposed by Smith, Soule, and Mosby in Bulle- 

 tin No. 19, part 2, of this series and indicates that water from the 

 upper faster-moving currents is contributed to the deep water circu- 

 lation, through mixing, cabbeling, and sinking along the boundaries 

 of the parent currents. 



With such an hypothesis in mind the explanation is at hand for 

 the lower mean temperature of the westward-flowing current inter- 

 secting the longitudinal section compared with the mean tempera- 

 ture of the West Greenland Current at Cape Farewell. Namely, 

 part of the water passing Cape Farewell sinks below the reference 

 level of the velocity profiles (1,500 decibars) and is replaced by colder 

 water of the Baffin Land Current as indicated by the surface map 

 (fig. 52). Further contributions to the deep water are made between 

 Davis Strait and South W^olf Island, not completely compensated 

 for by the addition of that part of the cold Baffin Land Current 

 which enters the Labrador Sea west of the longitudinal section. 



Only a very small amount of the West Greenland Current con- 

 tinued north across the Davis Strait section into Baffin Bay. This 

 small volume of flow of 0.12 million cubic meters per second had a 

 mean temperature of 2.79° C. compared with a previously measured 

 value of 1.2° C. It is probable that just north of Davis Strait Ridge 

 part of the Baffin Land Current crosses to the Greenland side and 

 joins the West Greenland Current on its way northward. If so it is 

 also probable that the earlier measurements included a part of this 

 cold cm-rent, increasing the volume figure and decreasing the mean 

 temperature figure, in which case the 1938 values would be more 

 nearly representative of the West Greenland Current which actually 

 crosses the ridge. That portion of the Baffin Land Current crossing 

 the Davis Strait section (east of station 2838) was found to have a 

 volume of flow of 0.53 million cubic meters per second and a mean 

 temperature of 1.72° C. As this represents by no means all of the 

 Baffin Land Current entering the Labrador Sea it is without sig- 

 nificance as far as that current is concerned. However, since this 

 water also crossed the longitudinal section at the northern end it 

 provides a means of correcting the apparent volume of flow of the 

 west-flowing branch of the West Greenland Current. Applying this 

 correction leaves as the true West Greenland Current a volume of 

 4.98 and a heat transfer of 20.6, which adjusted figures produce 

 a revised A^alue of the mean temperature of this branch of 4.13° C. 

 Even these adjusted values and the uncertain t}^ as to normal con- 

 ditions in this region leave as unescapable the conclusion that an 

 abnormally large proportion of the West Greenland Current branched 



