OCEAN CURRENTS 



173 



which runs from Scotland to the Faroes and thence to Iceland 

 and Greenland. The iso- 

 thermsof 5°, 10°, 15°, and 

 20° show a downward 

 curve between 25° and 35° 

 north and south latitudes, 

 whereas in the equatorial 

 régions they lie quite near 

 the surface. To account 

 for the température distri- 

 bution warm and cold ver- 

 tical currents are shown 

 in the diagram, upwardly- 

 directed cold currents in 

 the equatorial région, 

 and downwardly-directed 

 warm currents in the 

 temperate régions. 



The régions in which 

 the isothermal lines bend 

 upwards towards the sur- 

 face are precisely the 

 central régions of the 

 great circular currents — 

 e.g., between 25° and 35° 

 N. Lat. 



The influence of den- 

 sity on vertical circulation 

 is naturally most im- 

 portant. 



As an example of the 

 drif t of water due to différ- 

 ences in salinity let us take 

 the outflow of Mediter- 

 ranean water into the 

 North Atlantic. At depths of 1,000 mètres (547 fathoms) 



FiG. 33. — Température 

 THE Atlantic along 

 (G. Schott.) 



Section* of 

 0° W. Long. 



