The oceanic circulation and stratification regime on the East Florida Shelf (EFS) is driven by the adjacent baroclinic Florida Current (FC) (a segment of the Gulf Stream System), and by atmospheric forcing on seasonal and weekly (i.e., weather-system) time scales. For example, atmospheric cold front passages can produce transient coastal ocean upwelling and downwelling. (Tidal and runoff forcing are of secondary importance and, hence, are neglected here.) The FC tends to be topographically-trapped along the seaward edge (i.e., the shelf-break) of the EFS, yet it meanders and spawns (in the strong cyclonic shear zone at the shelf-break) FC frontal (cyclonic) eddies (FCFEs), also on a weekly time scale, and they penetrate onto the EFS and interact with EFS waters. The FCFEs are, thus, an oceanic equivalent to atmospheric weather systems, and, due to their role in cross-shelf exchanges of properties and materials, and in altering ecosystem dynamics, it is important to understand their life cycle, and any role that atmospheric forcing may play in that cycle.

This topic is addressed through numerical simulation using the baroclinic Princeton Ocean Model (POM) implemented with oceanic mesoscale resolution and on a curvilinear grid for the Straits of Florida. The ocean model is forced with seasonal inflow/outflow for the Straits, seasonal heating and cooling, and NCEP eta model winds. Simulations are made for a year or more. The sensitivity of FCFEs and coastal upwelling/downwelling to the space-time resolution of the wind-forcing is investigated.

Initial results indicate that the wind-forcing is not necessary for the initiation and development of the FCFEs. However, wind-forcing modifies the FCFEs, increasingly so with increasing space-time resolution of the winds. Investigation of the convolution and co-evolution of coastal upwelling/downwelling and FCFEs is in progress. Altogether, this study adds to the body of evidence bearing on the necessary and sufficient space-time resolution of atmospheric forcing required for accurate coastal ocean state estimation, and ,thus, this is a contribution to the ONR-sponsored SEA-COOS Program.