and was 86 percent at the time of the postseason cruise instead of the 

 supposed normal of 81 percent. As figure 20 indicates, there also was 

 some northward-flowing water inside the offshore corner of the Bona- 

 vista triangle during the postseason cruise. The volume transport 

 of the Labrador Current past the triangle was therefore somewhat 

 larger than tabulated for the postseason cruise, but the difference 

 was much smaller than for the fourth survey. It has been neglected 

 here and is not of the same order of magnitude as the difference 

 between the volume transport at the triangle and that of the Labrador 

 Current oft' South Wolf Island only 3 daj^s later. 



The circulation deduced from table 1 has been shown schematically 

 in figure 21. In this figure the volume transports have been rounded 

 off and adjusted in the Bonavista and Greenland triangles on the 

 assumption that there was no appreciable vertical transport past the 

 reference surfaces. Further reference will be made to this figure 

 after consideration of the sections occupied in the Greenland area 

 during the postseason cruise. 



It was pointed out in bulletin No. 39 of this series that more often 

 than not the minimum observed temperature was colder at the 

 Bonavista triangle than at the South Wolf Island section. This was 

 true again in 1954 when the minimum observed temperature at the 

 triangle was —1.67° C with a corresponding salinity of 33.15°/oo, 

 whereas the minimum observed temperature off South Wolf Island 

 was —1.58° C with a corresponding salinity of 32.85°/oo. Com- 

 parable average values for the 7 years during which observations have 

 been made are -1.65° C, 33.14°/oo, -1.53° C, and 32.8r/oo. 

 Since 1949 the volume transport of the Labrador Current at the South 

 Wolf Island section has been greater than average with the transport 

 in 1954 exceeding any of the other 16 years. Since 1950 its mean 

 temperature has been consistently above average until 1954, when it 

 dropped to 0.1° below average. The heat transport in 1954 is conse- 

 quently a high value, exceeded only by that in 1933, when a large 

 volume transport was accompanied by a high mean temperature. 



Labrador Current water and Atlantic Current water present in the 

 Grand Banks region have been found to have characteristic tempera- 

 ture-salinity relationships identifying them as water masses. Usually 

 also the mixed water formed from these parent water masses has a 

 sufficiently uniform proportion of the parent water masses so that it 

 can be regarded as a virtual water mass. The first three surveys of 

 the 1954 season were examined for T-S relationships. The fourth 

 survey was omitted as being located outside the area which has been 

 the source of the T-S data considered in the past. Figure 22 shows 

 the relationships found in 1954, as solid lines, in comparison with the 

 averages for the 8-year period 1934-41, shown in broken lines. In 

 general, all three water masses were lighter than the prewar average. 

 The differences were least in the Labrador Current water and here 



93 



