scarcely affected by the baroclinic deep-ocean responses in spite of 

 the fact that such modes contain significant energy. In addition, 

 the initial rise of water level before the peak surge (which, by 

 definition, is the forerunner)in the Galveston hydrographs obtained 

 from the two versions of HUR5 show no visual differences. Based on 

 these results, the baroclinic response is not important in the 

 forerunner surge phenomenon. 



The quasi-linear, coupled, normal mode model shows that the 

 hurricane induced forerunner surge in the Gulf of Mexico is 

 associated with a Gulf -wide oscillation of water level, tjq. The 

 ubiquity of the tjq signal in the hydrographs from stations around the 

 Gulf, except near Florida Strait, indicates that jjq is dominated by a 

 volume (i.e., Helmholtz) mode. The Helmholtz mode is characterized 

 by a relatively uniform amplitude and phase, except near the open 

 ports where the amplitude and phase changes rapidly. The forerunner, 

 therefore, has space scales comparable to the horizontal dimensions 

 of the Gulf of Mexico. 



Examination of the transport through the ports, particularly for 

 the 21 day simulations for PATHl, reveal large and nearly equal 

 amplitude but out-of -phase oscillations of about 6.5 day (156 h) 

 period. Superimposed on the 6.5 day oscillations are smaller 

 amplitude in-phase oscillations with a period of about 28 h. The out- 

 of-phase transport implies that when the transport is in one port it 

 is out of the other. It is the in-phase oscillations in transport 

 which are associated with the Helmholtz mode in the Gulf. The long 

 period out-of -phase oscillations in transport, on the other hand, are 



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