55 



seem that the region of Davis Strait is an important one in its effects 

 on the annual berg crop and the characteristics of the Labrador 

 Current. However, Httle can be done in a quantitative way at the 

 present time in the absence of any meteorological data from the Baffin 

 Land side of Davis Strait. 



SUMMARY 



1. The four surveys resulting in five maps of the Ice Patrol area in 

 the vicinity of the Grand Banks, made during the 1940 season, have 

 been described. 



2. The seasonal variation of the Labrador Current in the Grand 

 Banks region during 1940 has been compared with other variations 

 found during the previous six ice seasons on the basis of minimum 

 observed temperature, mean temperature, and volume of flow com- 

 puted for each occupation of each of three sections. 



3. Temperature-salinity correlations for the three types of water 

 found in the Ice Patrol area, Labrador Current water, mixed water, 

 and Atlantic Current water, have been investigated for each survey 

 of the region made during the 7-year period 1934-40, and mean curves 

 have been presented comparing conditions in 1940 with the 7-year 

 means. 



4. A new criterion of the boundary between the Atlantic Current 

 water and mixed water or Labrador Current water has been selected 

 and the boundary delineated for each survey made during the 7-year 

 period 1934-40. Fluctuations m the position of their boundary east 

 of the Grand Banks have been considered by studying the fluctuations 

 in an area enclosed by arbitrarily fixed lines on three sides and the 

 current boundary on the fourth side. A mechanism has been set up 

 for quantitatively separating the boundary fluctuations caused by the 

 Labrador Current from those arising from causes affecting the Gulf 

 Stream system. 



5. An apparent relationship, found between fluctuations in the dif- 

 ference in sea level, Bermuda-Charleston, and the vohnne of flow of 

 the West Greenland Current at Cape Farewell, Greenland, 1 year 

 later, has been described and two possible explanations offered. 



6. Abnormal thermal conditions found in the intermediate water 

 between southern Labrador and southern Greenland on the 1940 post- 

 season cruise substantiate the picture of the formation of deep and 

 bottom water in the Labrador Sea described in part 2 of Bulletin 19 

 of this series and are discussed in the light of that hypothesis. 



7. The volume of flow, mean temperature and heat transfer of the 

 Labrador Current at South Wolf Island have been computed from 

 measurements made during 1940 and compared with the results of 

 eight previous occupations of this section. Attention has been called 

 to the connection between low values of mean temperature and heat 



