to 300 meters it was more saline and of greater density. More 

 stations in the third sm-vey than the first survey were considered 

 atypical and thus were excluded from the averaging process. The 

 Labrador Current through 150 meters was colder and fresher on the 

 third survey (May) than on the first survey (April) ; conversely for 

 the same two surveys the Atlantic Current at all depths examined was 

 warmer and generally saltier on the third survey. 



As operational requirements have permitted, dynamic topographic 

 surveys have been adjusted to include the reoccupation of certain 

 sections across the Labrador Current from South Wolf Island, 

 Labrador, to the southern slope of the Grand Banks. For each such 

 occupation the temperature and velocity structure of the Labrador 

 Current have been examined and the volume transport, mean tem- 

 perature, heat transport and minimum observed temperature have 

 been recorded. As these data have accumulated, estimates of 

 tentative normal seasonal variation relationships have been made 

 and published from time to time. The location of these sections, 

 their designations and the most recently published tentative normals 

 are as follows: South Wolf Island, extending 045° T from South Wolf 

 Island, Labrador (normals published in Bulletin No. 44 of this series) ; 

 sections NW., SW., and SE., forming the northwestern, southwestern, 

 and southeastern sides of the Bonavista triangle having corners at 

 Cape Bonavista, 50° N., 49° W., and 47°24' N., 50° W. (new normals 

 shown in figure 25 of this bulletin) ; section H, parallel to and about 

 40 miles southeasterly of section SE. (normals shown in fig. 26 of this 

 bulletin); section G, extending northeasterly from about 47°10' N., 

 48°40 W. (new normals shown in fig. 26 of this bulletin); section F2, 

 an east-west section between the Grand Banks and Flemish Cap along 

 the parallel of 47°15' N. (normals shown in fig. 27 of this bulletin); 

 section F, similar to section F2 but about 30 miles farther south (new 

 normals shown in fig. 27 of this bulletin) ; section T, extending 

 southeasterly from about 46°20' IS., 49°00' W. ; section U, extending 

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

 southerly from the Grand Banks at about 50°15' W. (normals for 

 sections T, U, and W published in Bulletin No. 46 of this series). 



The normals shown in figures 25, 26, and 27 were derived by taking 

 an average value (in which each year represented was given equal 

 weight) plotted against its mean date as one point on the normal curve 

 which was drawn as a straight line whose slope was taken as the 

 average slope derived from years having two or more occupations 

 of the particular section. Individual occupations are identified by 

 the last two digits of the year of the observations and are shown to 

 indicate the variation from year to year. 



It should be explained that the term "heat transport," as used here 

 and in previous bulletins of this series, is the simple product of in-situ 

 temperature and volume transport obtained from the summation 



43 



