NUMERICAL-STUDIES OF EDDY SHEDDING IN THE GULF-OF-MEXICO

We model the eddy shedding phenomenon in the Gulf of Mexico using the Sandia Ocean Modeling System. In the first part of the study a paramet er sensitivity study is performed using a rectangular basin two-level model. In particular, the sensitivity of the model eddy shedding to in flow/outflow conditions, horizontal resolution (80, 40, and 20 km), an d reduced gravity is examined. The results are interpreted in terms of the quasi-geostrophic vertical motion equation and vorticity conserva tion. In the second part of the paper we include realistic coastlines and bathymetry in the model. A horizontal resolution of 20 km is used together with 16 vertical levels. Various observed features of the edd y shedding are simulated by the model. A boundary current which follow s topographic contours is generated around the Gulf because of the spl itting of the flows associated with the loop current and the shed eddy . This current is likely to be important in the dissipative stages of the eddies in the western Gulf. In addition, our results suggest that higher-order baroclinic modes are important in the dissipation of loop current eddies.