Hydrodynamics of the 2004 Florida Hurricanes

We studied the hydrodynamic response caused by the four major hurricanes that struck Florida's coasts in 2004: Charley, Frances, Ivan, and Jeanne. A large-scale, shallow-water-equation model was applied so as to simulate wind and tidally driven hydrodynamics from the deep ocean into the shelf and coastal waters of Florida. Hurricane Ivan served as the calibration case, where the adjusted parameter was the wind drag coefficient. We identified an increased wind drag coefficient to perform best and suggest it as a first approximation to the wave contribution to the hydrodynamics. The increased drag coefficient is offered to the consulting and/or forecasting communities, who are frequently without wave-modeling resources, as a pragmatic approach to approximate for waves. Hurricanes Charley, Frances, and Jeanne serve as the validation cases in which the increased wind drag coefficient was applied. Analysis was performed by inspection of maximum water-surface elevations, which are interpreted in terms of shelf and bay dynamics for the west coast hurricane cases (Charley and Ivan) and in terms of channel hydraulics for the east coast hurricane cases (Frances and Jeanne). We conclude that the broad shelf off Florida's west coast allows the storm tide to accumulate along the open coast and that the embayments further magnify the storm tide, and that the Atlantic Intracoastal Waterway along Florida's east coast is effective in propagating storm tide, where we show compartmentalization of the storm tide in the Indian River lagoon as caused by the flow impediment of the causeway abutments.