73 



tions were performed by the oceanographer's assistants, Bernard S. 

 Leobig, yeoman, first-class, and James F. Flannery, seaman, first-class. 



At the 201 stations occupied during the season, the extent and 

 nominal depths of the serial observations of temperature and salinity 

 where the same as during the season of 1936. On the post-season 

 cruise the observations were carried to as near bottom as was practical 

 at most of the stations in the region southwestward of Flemish Cap 

 and to 2,000 meters at the remaining stations. 



As a check on the functioning of the reversing thermometers, a 

 program of intercomparison through periodic shifts in thermometer 

 pairs was carried out as in 1936. A total of 1,378 individual compari- 

 sons were investigated. The probable differences between the 

 corrected readings of a pair of thermometers varied among the 

 different groups from 0.002° to 0.015° C. and the probable difference 

 for the entire 1,378 comparisons was 0.007° C. It is therefore con- 

 sidered that the observed temperatures are accurate to 0.01° C. 



The current maps prepared during the season w^ere made following 

 the procedure used in 1936, the season's maps being referred to the 

 1,000-decibar surface. The current map representing conditions 

 found on the post-season cruise is referred to the 2,000-decibar surface. 



In figure 34 is shown the current map resulting from the first sur- 

 vey, March 31 to April 10. This map shows a small part of the 

 Labrador Current rounding the Tail of the Grand Banks to the west- 

 rt^ard before curving south and east. A small pool of cold water is 

 jhown southwestward of the Banks and a larger pool southeastward 

 )f the Banks. This latter has an eastward extension which will be 

 -emarked upon later on. The maximum velocity of the Labrador 

 I!urrent is about normal, but the location, both of this maximum and 

 )f the westward intrusion of Atlantic Current water, is some 40 

 niles south of the usual location. The Grand Banks whorl was com- 

 paratively inactive, but, as the whorl is believed to be partly energized 

 )y the vernal warming over the southeastern shoal, its inactivity is 

 n accord with the early date of the observations. The edge of the 

 Atlantic Current is to be seen at the eastern border of the map. 



Figure 35 shows the current map made from data collected on the 

 second survey, April 27 to May 9. A notable feature of this map is 

 ihe amount of current commg off the Grand Banks northward of 

 atitude 44° N. A part of this is the Grand Banks whorl but it is 

 )elieved that considerable additions to the whorl from the western 

 )ranch of the Labrador Current are present in this survey. That the 

 vestern branch of the Labrador Current was flowing with abnormal 

 itrength is indicated by the unusual concentration of ice drifting 

 south along the Avalon Peninsula. This western branch spreads 

 an-like with rapidly diminishing velocities after reaching Cape Race. 



I 



