Chapter Twelve 



CONCLUDING REMARKS 



The central North Atlantic Ocean is covered to a depth of about 700 m. 

 with a layer of warm water, slowly drifting toward the southwest under the 

 combined influence of the stress of the wind and the earth's rotation. This 

 central body of warm water, called the Sargasso Sea, does not reach the 

 western coasts of the Atlantic Ocean (the eastern coast of North America), 

 but is bounded some distance offshore by the Gulf Stream — a narrow, 

 intense, northeastward-flowing current which returns to the north again 

 the southward-driven Sargasso Sea water that has passed through the 

 Caribbean and has turned through the Florida Straits. 



The Gulf Stream flows along the western boundary of the warm Sargasso 

 Sea surface water. As the Stream turns toward the east, off the Grand 

 Banks, it acts as a kind of djniamic barrier, or dam, which, by virtue of 

 Coriolis forces, restrains the warm Sargasso water from overflowing the 

 colder northern water of the North Atlantic. The water in the Stream is 

 not significantly different in temperature from the large mass of warm 

 water which Ues to the right of its direction of motion. The Gulf Stream is 

 not an ocean river of hot water. The intensity of flow of the Stream, the 

 Stream's direction, and its temperature are not primary chmatic factors in 

 determining the cUmate of Europe ; but the role which it plays in deter- 

 mining the northern boundaries and average temperature structure of the 

 Sargasso Sea must be of critical chmatic importance. However, we do not 

 yet know how this role is physically connected with such observables as 

 total transport. 



Certain remarks concerning the very nature of oceanographic research 

 itself are made in a later section of this final chapter. 



