170 MARION AND GENERAL GREENE EXPEDITIONS 



Atlantic Current ma}' be contributed directly to the offshore borders 

 of the West Greenland Current. 



Figure 126 is a composite dynamic topographic map of the entire 

 region from Smith Sound southward to the Tail of the Grand Banks. 

 The Baffin Bay part is based on the observations of the Godthaah 

 made in 1928. From DaA'is Strait to the line between Cape Farewell 

 and Newfoundland the map is based upon the 1928 Marion observa- 

 tions. From this line southeastward to Flemish Cap the observa- 

 tions of the General Greene taken on the 1935 post-season cruise 

 have been used and that part of the map in the vicinity of the 

 Grand Banks is based upon observations taken during May 1935 by 

 the General Greene. Blank strips separate the various areas de- 

 scribed above. The common reference level is the 1,500-decibar sur- 

 face. It must be remembered that figure 126 is a composite combin- 

 ing observations from different seasons and different years, not strictly 

 comparable but with this reservation in mind it is useful in gaining 

 a more complete picture of the current system as a whole and 

 of the interrelation of the component parts of that system. Figures 

 127 and 128 are similarly constructed composite horizontal sections 

 of temperature and salinity at a depth of 100 meters in summertime. 



The subsurface circulation obtaining in 1928 is illustrated in 

 figures 129 and 130, which are dynamic topographic maps of the 

 600- and 1,000-decibar surfaces, respectively, referred to the 1,500- 

 decibar surface. The major patterns of the surface circulation seen 

 in figure 122 are reflected in the course of the dynamic isobaths at 

 the 600-decibar surface. Most notable, perhaps, in figure 129 is the 

 illustration of the contribution of the West Greenland Current to 

 Baffin Bay over Davis Strait Ridge. Figure 130 demonstrates the 

 weak but cyclonic character of the circulation in the intermediate 

 water, with the center of the basin in less active circulation than 

 the borders. 



SUMMARY OF SURFACE CIRCULATION 



The surface circulation of the Labrador Sea is summarized as fol- 

 lows : The East Greenland Arctic Current and a western branch of the 

 Irminger Current on rounding Cape Farewell are renamed the West 

 Greenland Current which flows northwestward. The West Greenland 

 Current branches, part crossing Davis Strait Ridge into Baffin Bay 

 and a part flowing westward south of the Davis Strait Ridge and 

 joining Arctic water flowing southward out of Baffin Bay to produce 

 the Labrador Current. The Labrador Current, composed of about 

 three parts west Greenland water to two parts of Baffin Bay water, 

 flows soutlierly along Labrador and Newfoundland and the eastern 

 edge of the Grand Banks, eventually turning in a general northeast- 

 erly direction along the northwestern borders of the Atlantic Cur- 

 rent. From the northern edge of the Grand Banks to the Tail of the 

 Banks parts of the Labrador Current are turned back to the north- 

 ward. The northernmost of these returned branches forms a closed 

 whorl between the trunk of the Labrador Current, Flemish Cap, and 

 mixed waters of the borders of the Atlantic Current which water 

 flows northward and eastward extendins: as far as 55° north. 



