Study of Circulation in the Apalachicola Bay and the Surrounding Wetland Applying Triple-Nested Models Downscaling from Global Ocean to Estuary

To study the carbon fluxes between land and sea a high-resolution (~250 m) estuarine model that covers the Apalachicola Bay, FL and the surrounding wetland has been developed. The estuarine circulation is mainly driven by the tides and the river flows and to a lesser extent by the wind, evaporation and rainfall. Although the Apalachicola Bay is a semi-enclosed bay, its circulation is nevertheless connected to the open ocean and may have an impact from encroaching Loop Current and Loop Current eddies. A triple-nested model, therefore, was applied to connect the deep Gulf of Mexico to the coastal sea then to the Apalachicola Bay. The downscaling was done from the global model (~10 km) to the coastal model (1.5 km) and then to the estuarine model (250 m). The high resolution estuarine model has a wet and dry capability to deal with extreme shallow wetland and is forced with realistic tides, real-time river flows, wind and surface fluxes that include evaporation and rainfall. The characteristic circulation in the Apalachicola Bay and the surrounding wetland will be demonstrated and compared with measurements.