alter the results. For an asymmetric storm moving at 18 km/h, which 

 is comparable to the translation speed of Carla, in an idealized f- 

 plane basin, the wake oscillation has a wave length of approximately 

 420 km. The average wave length obtained from this Carla simulation 

 is approimately 360 km. 



6. Results of Allen simulation 



The results of the Allen simulation show a synchronous 

 oscillatory signal with a period of approximately 28 h in all of the 

 simulated hydrographs. The amplitude of this oscillation is 

 approximately 20 cm. The existence of this in phase signal in all 

 stations around the Gulf is indicative of a Gulf-wide, Helmholtz mode 

 superimposed on other forced modes. Consequently, an ad-hoc code to 

 compute the average water level in the Gulf proper (designated as tjq) 

 at each time step was added. Figure 33 shows the time series of tjq. 

 The solid line represents tjq computed by averaging water levels at 

 each grid point in the Gulf, and the dashed line is tjq computed from 

 the continuity equation using the difference of volume transports at 

 the Florida and Yucatan ports. The two curves are practically 

 coincident and very well matched with the signal present in the 

 individually computed hydrographs mentioned above. As it can be seen 

 in Fig. 33, this mode persisted throughout the entire simulation 

 period . 



The agreement between the simulated and observed hydrographs 

 (Figs. 34-46) is comparcible to that obtained in the Carla simulation. 

 This is surprising since less information regarding the atmospheric 



77 



