Induced Waves from Typhoon Maysak: Model Optimization and Evolution Characteristics in Yeongil Bay, South Korea

Abstract

Typhoon Maysak (TY2009) landed on the Korean Peninsula in September 2020, and the intense waves caused severe damage along the east coast of South Korea. In a previous study by Son and Do (2022), two wave model physics, ST1 (Komen, Hasselmann, and Hasselmann, 1984) and ST6 (Zieger et al., 2015), were compared. The results showed that the two models overestimated the significant wave height, especially with ST6, which utilized a wind friction velocity as the wind scale. Thus, the optimized wave model setup and effect of wind scaling variation in the ST6 physics were evaluated for typhoon-induced wave simulation. The model has also been applied to hindcast the wave fields in Yeongil Bay using the unstructured meshes with a horizontal resolution of 50 m. The results showed that the U10 application on the ST6 model reduced the wave height significantly. The model was further improved by implementing the UL2M2 parameterization (Rogers, Babanin, and Wang, 2012), although the maximum wave height during the typhoon event was underestimated. During the typhoon event, the observation data showed different wave evolution patterns at each station inside the bay. However, the present model was insufficient to capture the wave evolution process. Further studies that include the refraction-diffraction process and optimizing the parameters shall be inquired.