observed temperatures and salinities. Values of o-„ were determined^ 

 from an open curve representing the equation 



cr„ = -0.0934 +0.81487S -0.0004825S2 +0.00000677S3 

 Approximate values of at were obtained by applying a difference D to 

 (To (where at — (To — D) where D was taken from a plot of tempera- 

 ture against D for o-,, = 26.000. A final correction to these approximate 

 values of at for the departure of ao from 26.000, was taken from a 

 curve in which the change of D per unit change in (r„ was plotted 

 against temperature. Three decimal places in a-< were carried in the 

 computations in order that the accuracy of the results should be limited 

 by the errors of observation rather than by errors of computational 

 method. These departures from usual practice were followed in order 

 to mitigate the magnifying effect of the short horizontal distances on 

 apparent variations in dynamic height from station to station where 

 these variations are only the result of methods of computation. The 

 iceberg maps are referred to the 140-decibar surface, the season's maps 

 to the 1,000-decibar surface, and the post-season map to the 2000- 

 decibar surface. 



Figure 2 shows the current map resulting from the first survey. 

 Although the observations made during this survey were not as nearly 

 s>noptic as usual, they have been incorporated in a single map. This 

 map shows the Labrador Current to have been flowing with normal 

 surface velocities, and in the southeastern part of the area the Atlantic 

 Current was flowing with considerable vigor. A slight complication in 

 the current pattern was present immediately south of Flemish Cap, 

 with the circulation around the Cap in a clockwise direction. A slow 

 clockwise whorl was also present on the edge of the Grand Banks at about 

 latitude 46° N. It is considered that such a whorl may develop during 

 a period when the volume of flow is decreasing from causes upstream 

 or when the volume of flow is increasing with respect to conditions 

 downstream. The former situation is probable in this case. The Grand 

 Banks whorl, centered near the shoalest part of the Banks, was unusually 

 strongly developed for the time of year and indicated an abnormally 

 advanced season. This was borne out, especially in the southern part 

 of the area, by surface temperatures. In the southwestern part of the 

 area, the Labrador Current was found to extend farther west than 

 usual, but the current pattern was not favorable to extreme south- 

 easterly berg drifts. The intrusion of Atlantic Current water toward 

 the (jrand Banks, which characteristically occurs at about latitude 

 45° N., was present during this survey at about latitude 44° N. 



The results of the second survey are shown in figure 3. The lower 

 surface velocities of the Labrador Current in the northern part of the 

 map confirm the cause assigned above for the clockwise whorl appearing 

 in that part of figure 2. Farther south, however, at about latitude 44° N., 



' See Soule, Floyd M. Oceanographic conditions in the Grand Banks region and the Laborador Sea in 

 1939. International Ice Observation and Ice Patrol Service-in the North Atlantic Ocean — Seasonof L939. 

 U. S. Coast Guard Bulletin No. 29. pp. 96-97 (1940) Washington. • • • ' ■■ 



