A COMPARATIVE STUDY OF STORM SURGE MODELING ON DIFFERENT HURRICANE PATHS IN THE CHESAPEAKE BAY

Tropical cyclones originated in the tropical ocean frequently pass by Mid-Atlantic Bight region where the Chesapeake Bay, a 300 km long estuary, located. Among about 40 tropic hurricanes passed by the Bay region in the last century, there are two different paths of the storm track to which the Bay responds distinctly. One path belongs to the category of storm track passes by the eastside of the Bay in the open ocean. To which, the initial primary surge wave propagates through the Bay mouth interacts with the subsequent water level induced by the northly (toward the south) wind. As a result, the water level was set up in the Lower Bay and set down in the Upper Chesapeake Bay. In contrast, when the path of the storm track passes by the western side of the Bay on the land, the Bay responses with the primary surge wave interacts with the slope of the water level induced by the southly (toward the north) wind. This results in a set down in the lower Bay and set up in the Upper Chesapeake Bay; the setup is appreciable owing to the combination of the primary surge propagates northward and a very long fetch of the Bay for the persistent wind forcing. This is the case for the recent event of the Hurricane Isabel. A cutting-edge unstructured grid, finite volume/finite difference model was setup to simulate the storm surge under different paths of the storm tracks. The numerical model, after its proper calibration, creates a wealth of information which allows one to extract and analyze the detailed dynamics of surge interacts with the wind-induced set up and set down processes. The numerical model, thus, proves to be a very useful tool for the fundamental understanding of the storm surge process.