Survey #6, 17-20 March 1957, Figures 23-27 . 



Temperatures at this time ranged from 21°-26°C at the surface, and were 

 coolest offshore. The isotherms at 10 and 25 m show upwelling with the cool- 

 est water near the head of Panama Bay and near the Bay of San Miguel. Warm 

 waters persisted offshore and to the south. The upwelling was supplied with 

 cool water entering along the trough west of the Las Perlas Islands. 

 Survey #7. 10-12 July 1957. Figures 28-32 . 



The waters were warmer than 27°C over most of the Gulf to depths of about 

 25 m, and were about 19° or warmer to all depths recorded. This, then, is the 

 warmest period encountered in these surveys. 

 Survey #8, 7-8 November 1957. Figures 33-37 . 



Warm temperatures still prevailed over most of the Gulf of Panama at this 

 time, but the recorded values are l°-3° cooler than at the time of the previ- 

 ous survey. A warm water tongue was present above 25 ra, while wannest waters 

 at 50 m appeared in an area centered southwest of the Las Perlas Islands. The 

 isotherm pattern is consistent with the usual current pattern of counterclock- 

 wise flow through the Gulf, near the surface. 

 Survey ^. 18-21 March 1958. Figures 38-42 . 



The Gulf water was cool at the time of this survey but, according to data 

 included in Forsbergh's paper, was not minimal for the season. The isotherms 

 suggest a southward flow of upwelled water at the surface out of the Bay of 

 Panama. This flow is evident to at least 25 m, with cool water present in the 

 center of the Gulf and warm water on each side. The southward current seems 

 more evident than at the times of the previous surveys, and may be a conse- 

 quence of El Nino conditions prevailing at the time. At depths of 50 and 75 m, 

 the isotherms indicate a transport into the Gulf in the western side toward 

 its head. 



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