surface near the middle of the water column, rather than 

 at the sea surface, where the effects of wind stress may 

 be important. It seems likely that the capabilities of 

 the satellite altimeter program can be used much better 

 in ways other than solving the level-of- no-motion problem. 



Position of boundary currents and meanders . For many 

 years it has been known that the Gulf Stream follows a 

 complex, twisted path. Figure 3, from Gorton (1970) shows 

 the positions of the inshore edge of the Gulf Stream as 

 determined by an infra-red thermometer flown in an airplane. 

 The inshore edge is the region of strong horizontal temperature 

 gradient which shows up so well by this technique. The 

 instantaneous Gulf Stream is approximately 100 km wide. The 

 meanders generally seem to grow larger, as shown by Hansen (1969) 

 At approximately 60° w, the meanders may be 500 kilometers 

 in horizontal extent, and perpendicular to the stream. 



A realizable goal for the satellite program would seem 

 to be finding the strong boundary currents. The satellite 

 technique offers promise of locating, on an ocean-wide 

 basis, the major western boundary currents of the entire 

 world ocean for the first time. Pointing out their locations, 

 world-wide, would be a worthy result. How far from the 

 continental masses do the currents retain their identity? 

 What is the persistence of the meanders? How often do 

 meanders grow large enough to spawn eddies that detatch 

 from the stream and drift away? Are the answers to these 

 questions the same in the Gulf Stream, Kuroshio, Brazil 

 Current, and others? Does bottom topography affect the 

 meanders? These are questions which could be answered 

 at present with infra-red thermometers from airplanes, but 

 with satellites it would become feasible on a large geographic 

 scale. The infra-red techniques are strongly limited 

 by cloud cover, so the altimeter would be an improvement. 

 A logical question seems to be that if the infra-red techniques 

 could find a meander, could the satellite altimeter continue 

 to track it? There are other currents that meander, such 

 as the path of the main flow in the Gulf of Mexico, which is 



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