Analyses of storm surges in the western part of the Seto Inland Sea of Japan caused by Typhoon 9119

The 19th typhoon of 1991 (hereafter referred to as Typhoon 9119) caused remarkable storm surges more than 3 m in height with great inundation resulting along the coast in the western part of the Seto Inland Sea of Japan. This paper discussed the generation mechanism of storm surges due to Typhoon 9119 using numerical simulations with the conventional two-dimensional model. Some discrepancies between calculated storm surges and those observed were found, the reason for which was assumed to be lack of accuracy in the typhoon model. A method was developed to estimate wind field in a typhoon using sea level data and adopting the D. J. Schwab method (1982) Dynamics of Atmosphere and Oceans, 6, 251–278. Comparison of the estimated wind field with the observed wind field showed good agreement. Using the estimated wind field and newly determined normal modes of the analyzed region, the detailed structure and the generation mechanism of the storm surge resulting from Typhoon 9119 are identified.