survey was made in 1955 it is not possible to judge whether the time 

 lag of 11/2 months, which has been found in the post-war years, was 

 still effective or whether the prewar lag of 13}^ months should have 

 been used. 



For a number of years the cii-culation in the upper layers of the 

 waters in the vicinity of the Grand Banks has been studied in some 

 detail through examination of the distribution of velocity and temper- 

 ature in selected vertical sections across the Labrador C-urrent. The 

 values of volume transport, mean temperature, minimum observed 

 temperature and heat transport so derived from observations made 

 in 1955 are given in table 1. In this table and in the discussion 

 volume transport is in millions of cubic meters per second, heat 

 transport is in millions of cubic meter degrees Centigrade per second 

 and mean temperature and minimum observed temperature are in 

 degrees Centigrade. Sections T, U, and W are located as follows: 

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

 extending easterly from the Grand Banks at about 45° N.; and W 

 extending southerly from the Grand Banks at about 50° W. Sections 

 NW, SW and SE are the sides of a triangle the corners of which are 

 located near Cape Bonavista, Newfoundland, about 50° N., 49° W., 

 and about 47°20' N., 50° W. Section F extends easterly from the 

 Grand Banks to Flemish Cap and sections G, H and HN radiate 

 seaward from the northeastern shoulder of the Grand Banks succes- 

 sively northward between section F and the Bonavista triangle. 

 The South Wolf Island section extends northeasterly from South 

 Wolf Island, Labrador. Rough approximations to seasonal normal 

 variations have been developed and published for sections T, U and W 

 in bulletin number 36 of this series and for sections NW, SW and SE 

 in bulletin number 39 Such seasonal normal values have been given 

 in table 1 . The several occupations of the South Wolf Island section 

 have all taken place at about the same time of year and average 

 values are given for this section in lieu of normals. Sections F, G, 

 H and HN have not been occupied a sufficient number of times to 

 provide either seasonal normals or useful average values. 



In the first survey the volume transport of the Labrador Current 

 decreased southward from sections F to T to U as portions recurved 

 northeastward. At section W the increase over section U is con- 

 sidered to be the effect of a recirculatory closed eddy between the 

 supply from the north and the off-lying Atlantic Current. The mean 

 temperature at section T was below normal, at section U about normal 

 and at section W above normal. Wliile at section T the minimum 

 observed temperatm-e was about a quarter of a degree above normal, 

 at sections U and W it was about a half degree warmer than normal. 

 These temperature variations are interpreted as indicating that an 

 increase in flow of colder water from the north was taking place at 

 about the time of the survey. 



.381.304 — 5€ 



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