Recent record-breaking high ocean waves induced by typhoons in the seas adjacent to Korea

Estimation of extreme wave heights (EWHs) is the most important factor in the design of coastal structures such as breakwaters. In Korean coasts, the most EWHs occur during typhoon events. Recently, a number of ocean wave buoys have been deployed in the seas adjacent to Korea. This enables the measurement of record-breaking high waves during passages of recent strong Typhoons Kompasu (1007), Muifa (1109), Bolaven (1215), and Sanba (1216). This study investigates the characteristics of extreme waves during the passages of typhoons using buoy measurements and a numerical model. The wave simulations using WAVEWATCH III show that the model has the capability to reproduce the most EWHs during the four aforementioned typhoons with high accuracy, which guarantees an explanation of the mechanisms on the causes of such high wave generations over these regions. The analysis reveals that the occurrence of EWHs is influenced by not only storm intensity (i.e., maximum wind speed), but also the size, translation speed, and track of typhoons. Particularly, the record-breaking maximum wave height of 19.7 m observed during Typhoon Bolaven was the combined result of high winds, fast translation speed, big size, and straight track of Bolaven, which can maximize the increase of the dynamic fetch and duration.