Contribution of wind-forced coastally trapped waves to coastal sea level rise during a hurricane

During the Hurricane Dennis, July 5-13, 2005, unexpectedly high sea level rise was observed in the Apalachee Bay, Florida. It is hypothesized that the hurricane generated a barotropic wave traveling along the shelf in the same direction as the hurricane track, which was amplified as it traveled along the West Florida coast to Apalachee Bay. Idealized and realistic model experiments are run to study the ocean response to a hurricane moving along the shelf. Both experiments use Navy Coastal Ocean Model (NCOM). In the idealized model experiment, the model domain is a barotropic ocean over a long shelf on the f-plane forced with a cyclonic wind stress calculated from an analytical hurricane pressure field. The center of the hurricane is placed at 430 km off the coast. The hurricane is translated with different speeds along the shelf to view the dependence of the wave characteristics on the atmospheric forcing. It is assumed that when the translation speed of the hurricane is close to the phase speed of the wave the sea surface height anomaly is amplified as the wave travels along the shelf. The realistic simulations are performed using the NCOM configured for the Gulf of Mexico coupled to an atmospheric flux model forced by satellite scatterometer-derived winds and atmospheric model air temperature data.