A simple geostrophic calculation using an instantaneous volume 

 transport through Florida Strait at 1600 h on day 8 of 30 x 10^ m-^/s 

 and an average depth across the port of 950 m yield a northward 

 surface gradient from Cuba of 0.2 m. A similar computation for the 

 Yucatan Strait yields a surface gradient toward Campeche Bank of only 

 0.07 m. The surface height field is not available for comparison. 

 However, using the mean water levels at Dimas and Key West as a rough 

 representation of the north-south surface component of gradient 

 reveals that the tilting of water surface across Florida Strait is on 

 the order of 0.5 m. This result is much larger than that obtained 

 from the simplified geostrophic calculation. It is quite possible 

 that the current speed is not uniform across the ports. An estimate 

 of the effect of current shear on the cross-port surface gradient by 

 numerically integrating the geostrophic equation across the port was 

 made. This integration is given by the relation 



JJj+1 = Tjj + (AyfU/gDj+J) , (79) 



where U is the transport per unit width for each grid block across 

 the Florida Strait and D-j+l is the average depth for each block. 

 Upon assuming uniform distribution of transport across the port, U is 

 Q/W where Q is the total volume transport and W is the port width. 

 Employing the same value of Q as in the previous calculation and 

 taking the water level at Cuba (south of Key West) as zero yields a 

 surface gradient between Key West and Cuba of 0.5 m. For the Yucatan 

 Strait the tilting of water surface between Cuba and the east coast 

 of Yucatan obtained from this computation is 0.26 m. Even though Q 



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