264 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1932 



repeat these sections quarterly. They should provide information 

 concerning fluctuations in velocity and in volume of the Gulf 

 Stream. They should show whether or not its path varies with the 

 season and from year to year. Since on these sections the stations 

 have been spaced at from 15 to 25 mile intervals, they should give 

 reliable data on the internal arrangement of the water layers in 

 what is perhaps a purely convectional current. The cruise from 

 Nova Scotia to Bermuda and back to Chesapeake Bay can usually 

 be made in under two weeks, so that the sections come very close 

 to satisfying the ideal of giving an instantaneous picture. 



Although this work is perhaps mainly of interest because it will 

 supply detailed information on the Gulf Stream, the greater part 

 of the sections lie in the relatively motionless mass of the central 

 North Atlantic water. In this region between the Gulf Stream and 

 Bermuda the stations will be most helpful in the study of such 

 questions as internal boundary waves, the mixing action of storm 

 waves, and other questions important over the whole ocean rather 

 than applying to currents. Between the Gulf Stream and the edge 

 of the continental shelf there is also another interesting band of 

 water which is relatively cold at all depths when compared to the 

 water just to the south and eastward. Yet it is not at all certain 

 that this strip of water, which can be thought of as keeping the 

 Gulf Stream away from northern Atlantic coasts, has a northern 

 origin. 



Besides these Bermuda sections the Atlantis has run two long 

 north and south profiles in mid-Atlantic. The more northerly line 

 of stations follows longitude 30° W. and crosses the North Atlantic 

 Drift, as the continuation of the Gulf Stream is sometimes called. 

 Before this section was run (July, 1931) there was evidence that the 

 Gulf Stream split into at least three branches after leaving the 

 region of the Grand Banks and that the prevailing westerly winds 

 in this part of the ocean played an important part in the easterly 

 movement of the surface waters. The Atlantis section of closely 

 spaced stations should furnish important data concerning the water 

 movements in this part of the ocean and at the same time definitely 

 establish the branching nature of the continuation of the Gulf 

 Stream. 



The southern of these two profiles (February, 1932) follows lon- 

 gitude 42° W. and extends from the horse latitudes to the Equator. 

 It therefore crosses the northern equatorial, or trade-wind, current. 

 In theory, this section should show up the nature of a pure wind 

 current besides giving the volume and velocity of the westerly drift 

 across the southern part of the North Atlantic. It was hoped that 

 the arrangement of the water layers in this type of current would 



