SUMMARY 



1. The circulation in the ice patrol area in the vicinity of the Grand 

 Banks during the 1948 season, as derived from three current surveys 

 and portrayed by as many dynamic topographic maps supported by sev- 

 eral vertical temperature sections, has been described. 



2. The temperature-salinity relationships of the different water 

 masses found in the vicinity of the Grand Banks in 1948 have been 

 compared with results obtained prior to 1941 and discussed in terms of 

 the mixing zones along the boundaries of the Labrador Current and the 

 Atlantic Current. 



3. The volume of flow and mean temperature of the Labrador Current 

 past three selected sections during the 1948 season have been com- 

 pared with the results of similar measurements made during the period 

 1934^1. 



4. Three sections, disposed in the shape of a triangle just north- 

 ward of the Grand Banks and including the area in which the Labrador 

 Current divides into the branches which flow along the Avalon Peninsula 

 and along the eastern slope of the Grand Banks, have been discussed 

 with regard to the volumes of flow in the two branches and the location 

 of their separation. 



5. The thermal conditions in the intermediate water of the Labrador 

 Sea found in 1948 have been compared with those found during the 

 period of earlier measurements ending in 1941. 



6. The results of a study of five sections across the major currents 

 in the Labrador Sea and Davis Strait, presented in the form of a balance 

 of volume of flow, indicate that in 1948 a deficiency in the Irminger 

 Current was partially compensated for by a direct contribution from the 

 North Atlantic eddy to the circulation of the Labrador Sea. 



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

 West Greenland Current past Cape Farewell and of the Labrador Cur- 

 rent past South Wolf Island have been compared with the results of 

 earlier occupations of these sections. 



8. The results of field tests of a new instrument, the von Arx geo- 

 magnetic electrokinetograph, operated over a distance of about 3,500 

 miles, have been summarized. 



The data collected during the 1948 season and post-season cruises 

 are tabulated below. The individual station headings give the station 

 number, date, geographic position, depth of water, and the dynamic 

 height of the sea surface used in the construction of the dynamic topo- 

 graphic charts shown in figures 17, 19, 2(5, and 27 for which the dynamic 

 heights have been referred to the 1,000-decibar surface, and for figure 

 31 for which the dynamic heights have been referred to the 1,500-decibar 

 surface. The depths of water are uncorrected sonic soundings based on 

 a sounding velocity of 800 fathoms per second. Where the depths of 

 the scaled values are enclosed in parentheses the data are based on 



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