Major Research Identification of issues and improvement of wave estimation methods applicable to Japan's coastal areas

This study is intended to improve our existing wave model in terms of its ability to simulate or predict the temporal and spatial variation characteristics of sea breeze, the process of fetch-limited wave development, the sheltering effect of coastlines, and their interaction with seabed topography, which are all specific to coastal areas, and to use it to perform high-resolution wave simulations for the medium to long term concerning Japan's coastal areas. For our FY2020 activities, we analyzed the wave fields that occurred in Tokyo Bay during Typhoon Faxai in 2019, formulated a plausible hypothesis for a mechanical process that explained the wave conditions that arose in the open sea near Yokohama Port (i.e., formation of bidiectional wind waves and arrival of swells), especially as to why Yokohama Port suffered most of the damage caused by the typhoon, and confirmed that the reproduction precision of the wave model would vary depending on the sea wind load products. In addition, we monitored swell activities entering Tokyo Bay to understand their propagation process, and conducted long-term hindcasting on the Sea of Japan.