The Tropospheric Circulation 



613 



Equatorial Current, together with that carried by the Guiana Current and passing 

 between the Lesser Antilles will be about the same as the total transport of the Gulf 

 Stream through a cross-section off Cape Hatteras. From this it follows that the part 

 of the Gulf Stream that passes through the Florida Strait makes up only about a 

 third of the total transport. According to WiJST the Antilles Current carries 12 million 

 mVsec and the Florida Current about 37 million m^/sec. From here the current enters 

 regions with larger depth and there occurs a rapid increase in the water transport 

 because the current absorbs water masses with a temperature of less than 8 ° C from 

 the lower layers of the south-western Sargasso Sea. Further along to the north and 

 north-east the Gulf Stream is subject to a velocity decrease and an increase in width, 

 but the water transport remains nearly constant. However, it becomes more and more 

 difficult to distinguish its limits from the surrounding sea. Iselin has attempted to 

 divide up the Gulf Stream velocity profile at Chesapeake Bay (Fig. 284) into individual 

 inflow components (Fig. 285). The area A contains water warmer than 20° C and the 



c 



200 

 400 

 600 

 800 

 1000 

 1200 

 1400 

 1600 

 1800 



^ 







Fig. 285. Subdivisions of the velocity profile across the Gulf Stream off Chesapeake Bay, 



20-22 April 1932. The figures give the transport (in mill, m^ sec"^) for the different parts of 



the current (according to Iselin). 



velocity of this gives a transport of 10-6 million m^sec. The same layer in the Florida 

 current according to the WUst profile corresponds to 13-1 million m^sec and in the 

 Antilles Current to 4 million m^sec. The sum of these two is greater but no more so 

 than could be due to differences in the homogenity of the material. The area B contains 

 only water colder than 8° C, most of which was absorbed by the Gulf Stream in the 

 section with a larger depth. According to the velocity profile tliis area corresponds to 

 12-7 million m^/sec and only a very small part of it can possibly be assumed to have its 

 origin in the Florida Strait. Water is also drawn into the main current along both 

 edges by friction and mixing. If these areas in the profile are limited by the isoline of 

 20 cm/sec, these areas C and D will correspond to a transport of 0-7 and 12T million 

 m^sec respectively. These figures indicate that water is drawn into the current on the 

 right-hand side much more strongly than along the more sharply defined left-hand 

 boundary. The remaining area E corresponds to 46-1 million m^/sec. In the Wiist 

 profile for the Florida Current and the Antilles Current this area corresponds to 



