Numerical simulation of tide and storm surges in the Seto Inland Sea using the Princeton Ocean Model

Abstract

Tide and storm surges in the Seto Inland Sea were numerically simulated in a σ coordinate system using the Princeton Ocean Model (POM). For tide simulation, we obtained good results compared to the astronomical tide, particularly overall amplitude and phase features. For storm surge simulation, results from the model show sea surface elevation time series similar to that observed at each station. Several differences also arise, however. The discrepancy is attributable to the sea surface wind field over a wide area and the lack of sufficient resolution. More important ingredients are involved in reproducing the coastal region storm surge than nonlinearity or 3 dimensionality, however. Maximum sea surface elevation values for each location calculated using a 3-dimensional, stratified model were found to be up to about 10% larger than those calculated with a 2-dimensional, barotropic model. A physical explanation is proposed here. Tidal motion and storm surge are found to be almost independent in our simulations; that is, results are obtained merely by superposing the simulation driven by each independent forcing.