days of the simulation correspond very closely to the 3.4 day mode of 

 the Cayman Sea. This implies a complicated response of the Gulf- 

 Caynan Sea system which oscillates in unison at a period of 3.4 days. 

 Simultaneously the Gulf of Mexico exhibits a 28 h volume mode 

 superimposed on the long period oscillation. The latter mode can 

 clearly affect the time-dependent amplitudes assigned to tjq. 



The intriging questions of course concern the nature of the 3.4 

 day oscillation. Definitive answers are outside the scope of this 

 research. However, the influence of the earth's rotation could be so 

 readily evaluated that it was decided to repeat the above simulation 

 with the Coriolis acceleration set to zero. These results are shown 

 in Fig. 95. 



The 3.4 day mode was not excited in the non-rotating Gulf and 

 Cayman basins. Inspection of the accompanying digital means did not 

 reveal a discernable 3 day mode. Moreover, the digital time series 

 show that the 28 h volume mode in the Gulf was reduced to amplitudes 

 on the order of a centimeter. 



Notice that the paired histories of water level with (cf . Fig. 

 94, p. 158) and without (Fig. 95) rotation are different over the 

 entire period of forcing (first 3 days 22 h) . This suggests that the 

 excitation mechanism for the Helmholtz mode in the Gulf and the 3.4 

 day Gulf -Cayman system mode is contingent on the earth's rotation. 



159 



