Unexpected Storm Surge Caused in Mikawa Bay and Its Generation Mechanism

Abstract

It has been considered that Mikawa Port located in the eastern inner part of Mikawa Bay is safe for the storm surges in the case of a typhoon passing the south of Mikawa Bay because wind-drift effects are not excited on them. However, a storm tide 2.8 m, which exceeds the largest storm tide 2.6 m ever recorded in Mikawa Port and design values for the storm tide 2.75 m, were predicted by a potential vorticity bogussing scheme of a tropical cyclone and an atmosphere-ocean-wave coupled model. Simulated results using the scheme and model showed that the principal cause of the storm tide 2.8 m is not the wind-drift effect but a water oscillation in Mikawa Bay.