Mechanism of Abnormal Storm Surges after Passage of Typhoons around West Coasts of the Sea of Japan

Abstract

The present study discusses the mechanism of abnormal storm surges occurred at Sakai-Minato located west coasts of the Sea of Japan due to Typhoon Songda. The storm surge simulations by SuWAT (Surge-Wave-Tide coupled model) are conducted with and without Coriolis forces and river discharges as well as using different calculation regions. The analysis indicated that the Coriolis force is a predominant factor for the abnormal storm surge with time lags of 15 hours at the coastal regions in the Sea of Japan if the meteorological forcing is correct. The maximum contribution of the Coriolis force to the peak storm surge is 70 %. The influence of the river discharge is insignificant. For the storm surges generated in the Pacific Ocean, the effect of the Coriolis force is insignificant as about 1 % for the Typhoon Anita's storm surge.