Chapter Ten 



FLUCTUATIONS IN THE 

 CURRENTS 



Many catastrophes of an economic kind, such as the failure of the rice crop 

 in Japan, or of a certain fishery, or years of unusual numbers of icebergs in 

 shipping lanes, are attributed to fluctuations in ocean currents. Very httle 

 is really known about such fluctuations. It takes years of careful and 

 expensive observation to produce even a very crude description of them. 

 The scientific programs of our oceanographic institutions are not geared to 

 long-term problems of this kind ; there is much pressure for novelty, much 

 temptation to foUow the latest fad, and a persistent though erroneous 

 notion that all worth-whfle problems Avill eventually be solved by some 

 simple, ingenious idea or clever gadget. A weU-planned long-term survey 

 designed to reveal fiuctuations in ocean currents would be expensive and 

 time-consuming. It might even fail, because of inadequacies of the tools 

 we have at hand. But until this burdensome and not immediately reward- 

 ing task is undertaken, our information about the fluctuations of ocean 

 currents will always be fragmentary. 



THE DYNAMICS OF THE FLORIDA CURRENT 



Numerous studies of tide-gauge data have been made (Hela, 1952; Mont- 

 gomery, 19386), to obtain information about seasonal fluctuations in the 

 cross-stream slope of the sea surface ; and then, by the geostrophic equa- 

 tion, to compute seasonal fluctuations of the mean surface velocity of the 

 Florida Current. In addition to the tide-gauge data already published 



