| The synoptic circulation response of the West Florida continental shelf to idealized upwelling favorable wind forcing is studied using the three-dimensional, primitive equation Princeton Ocean Model. The initial spin-up process, evolving quickly within one day, starts with a mass redistribution in the surface Ekman layer, and continues with the development of a sea surface deformation that induces the coastal jet, the bottom boundary layer response, and coastal upwelling. During this process, the partially closed Florida Keys and the change in coastline orientation within the Big Bend greatly affect the sea level and circulation patterns.;Southeastward alongshore wind lowers the sea level along the coast and drives a northwest-oriented U-shaped circulation system that consists of a strong southeastward coastal jet and a relatively weak northwestward return flow farther offshore. The near-bottom onshore flow causes upwelling in the middle-inner shelf regions to compensate the surface offshore Ekman transport. The following baroclinic features distinguish the baroclinic circulation from the barotropic one: the vertical shear of the flow field is enhanced and the energy is trapped in the upper water column; the coastal jet is narrower but stronger; the upwelling occurs in a long narrow strip instead over the whole middle-inner shelf; and the piling-up of the water in the Florida Bay becomes more pronounced.;Offshore wind lowers the sea level along the West Florida coast and raises the sea surface along the Panhandle coast. The barotropic circulation system includes two circulation gyres that are separated by the Florida Big Bend. The southern gyre consists of a southeastward coastal jet and a broad mid-shelf return flow; and the northern one involves a strong northwestward coastal jet and an adjacent narrow southeastward undercurrent. In a baroclinic setting, a further offshore set-up of the sea surface results in an energetic southeastward undercurrent through the whole middle shelf. This undercurrent feeds the two oppositely directed coastal jets in the Big Bend, and off Tampa Bay and Naples, and causes regional upwelling centers in these places. The northwestward return flow of the southern coastal jet from the Florida bay floats over this undercurrent. Asymmetric responses under oppositely directed wind stresses, coastally trapped waves, and Rossby-type eddies on the shelf are also simulated in this study. |
