the mean temperature remained constant. At South Wolf Island the 

 Labrador Current had a volume of flow nearly 50 percent greater than 

 average, continuing the large values of volume transport which have 

 been found there each year since and including 1949. The mean 

 temperature at this section has been warmer than average and con- 

 stant at 2.63° during each of the last 3 years. This would seem to 

 give some weight to the speculation that more of the waters of the 

 Labrador Sea recently have been brought into the closed circulation 

 around its margins. 



Considering the volumes of flow past the three sections of the Bona- 

 vista triangle, if there is no significant vertical motion across the 

 reference surface the sum of the volume transports entering the triangLe 

 should equal the sum of the transports leaving the triangle. The 

 figures for the April occupation showed a discrepancy of about a 

 half-million cubic meters per second and it is presumed that some 

 change occured during the period covered by the observations in spite 

 of the good agreement between the two occupations of the station at 

 the northeastern corner made at the beginning and end of the 3-day 

 period of observations. The discrepancy was again about a half- 

 million cubic meters per second for the figures obtained from the July 

 occupation. In each case practically all of the current was following 

 the eastern branch. For each occupation the dynamic topography 

 at 100 decibars showed a pattern sunilar to that at the sea surface. 

 Figure 11 shows the dynamic topography of the sea surface in the 

 Bonavista triangle found during the postseason cruise. 



In the Grand Banks region Labrador Current water and Atlantic 

 Current water are present as water masses having characteristic 

 temperature-salinity relationships. Usually, in addition, the mixed 

 water formed from those water masses has a sufficiently uniform pro- 

 portion of each to be considered as a virtual water mass. The T-S 

 relationships found for these three water masses during the second 

 and third surveys of 1952 have been examined and curves representing 

 them are shown as solid lines in figure 12. The curves shown as 

 broken lines give the relationships representing the means for the 

 8-year period 1934-41. The two sets of curves are of much the same 

 shape for the Labrador Current water and the mixed water. There 

 is a notable difference, however, between the 1952 conditions and the 

 8 -year mean in the Atlantic Current water. Level for level the 

 Atlantic Current water was lighter in 1952 than the mean, and the 

 salinity minimum which occurs at a temperature of about 6° C in 

 the mean curve was absent in 1952 and was only hmted at by a bulge 

 occurring at a temperature of about 5° C. Although the 1952 curves 

 for the mixed water and the Labrador Current water are similar in 

 shape to the mean curves, the former at all levels and the latter at 

 the deeper levels show lighter than mean densities because of de- 

 creases in salinity. 



42 



