Grand Banks at about latitude 44° N., and reducing the amount of 

 Labrador Current water south of that latitude. The Grand Banks 

 eddy was present in this survey. The Labrador Current entered the 

 northern part of the survej^cd area in greater quantity than in the 

 first two surveys and a major portion of it was diverted eastward 

 north of about the 44th parallel. Probably the southward progress 

 of the Labrador Current was even more completely blocked in the 

 vicinity of 44° N., 49° W., than has been shown in figure 18. It is 

 also probable that the dynamic topography is not as simple as that 

 indicated and that a closed eddy existed in the vicinity of 45° N., 

 47° W., with the bulk of the Labrador Current water moving more 

 directly eastward south of the eddy. The clue to these surmises is 

 held in the characteristics of the subsurface water in this area where 

 cold water with temperatures as low as — L5° C was found at the 

 unusually far eastward location of station 4225. 



Section W, the north-south section near the 50th meridian, was 

 extended south to the 38th parallel to get additional data on the 

 complete Atlantic Current in this sector of the North Atlantic eddy. 

 While it is kno\vn that the 1,000-decibar surface is not sufficiently 

 deep for use as a motionless surface beneath the Atlantic Current, 

 the dynamic heights of the surface at the stations comprising section 

 W are referred to the 1,000-decibar surface here in order that the 

 pattern of the general circulation in this part of the survey may be 

 presented in the same illustration with the rest of the survey. Section 

 W will be treated in greater detail in a later part of the discussion. 



Li earlier bulletins of this series the volume of flow, mean tempera- 

 ture and minimum observed temperature of the Labrador Current 

 passing certain sections in the Grand Banks region have been reported 

 upon. The location of these sections, T, U, and W are as follows: 

 section T extending southeasterly from about 46°20' N., 49°00' W.; 

 section U extending eastward across the eastern edge of the Grand 

 Banks at about the 45th parallel; and section W extending southward 

 across southern edge of the Grand Banks at about the 50th meridian. 



Section T usually gives the total Labrador Current entering the 

 area east of the Grand Banks and south of the 47tli parallel and car- 

 rying all of the bergs which may endanger shipping following routes 

 southward of and including track E. Section U usually gives this 

 total Labrador Current plus a large part of the Grand Banks eddy 

 minus any of the Labrador Current which has recurved northeastward 

 between sections T and U. The loss of Labrador Current water re- 

 curving between these sections is ordinarily small so that the volume 

 at section U is usually larger than that at section T. wSection W is not 

 as definitely characterized as the other sections since there is ordi- 

 narily a major loss of Labrador Current water through recurving and 



67 



