560 



Basic Principles of the General Oceanic Circulation 



100° 



30 



20 - 



100 



30 



20 - 



!00 



Fig. 256. Schematic picture of the sea surface currents in the Gulf of Mexico (according 



to Schumacher). 



The current then enters the Gulf of Mexico through the Yucatan Channel with veloci- 

 ties of up to 3-7 knots at the current core. The currents of this mediterranean sea are 

 shown in Fig. 256 (Schumacher, 1940). The major part of the stream lines leaving the 

 Yucatan Strait tend to circle or cross the Gulf clockwise following the shelf line. The 

 branch that flows directly to the Florida Straits is stronger and is steady only during 

 the winter months. 



The eastern branch of the Yucatan Current forms the Florida Current the water 

 transport of which is the main source of the Gulf Stream. No other ocean current has 

 been so intensively investigated as this. An enormous amount of literature has been 

 accumulated on the subject that is impossible to cite here in detail. The water piled 

 up in the Gulf of Mexico flows out through the Florida Straits towards the north as a 

 gradient current (Florida Current) against the prevailing winds. This current becomes 

 stronger where the channel narrows off Bimini and may have a velocity of over 60 



