Probabilistic assessment of storm surge potential due to explosive cyclogenesis in the northwest Pacific region

Explosive cyclones formed in the northwest Pacific region can be categorized into three major types based on their evolution: Type-I cyclones develop over the Sea of Japan, Type-II are generated on the continent and move toward the Pacific Ocean, and Type-III travel northward in the Pacific Ocean along the Japanese archipelago. We performed computational experiments of past storm surges to find statistical features of local sea levels, depending on the types of the cyclone evolution under a realistic meteorological scenario of winter cyclones, with an aim to provide possible sea-level rise expected in the northeast Asia. Here, we show that amplification of local sea level, governed by the orientation of coastal lines with cyclone tracks, is defined by the evolution type that is classified by their trajectories, rather than the intensity, of the cyclone. Nemuro Bay is the most vulnerable site in the northwest Pacific region regardless of the evolution type. Severe storm surges are also expected along certain other semi-enclosed coasts facing the northern Sea of Japan and Sea of Okhotsk due to Type-I cyclones. The probabilistic evaluation of sea levels depending on the cyclone evolution type as introduced in this study may be useful for evaluating potential disasters.