Faxai(2019)およびHagibis(2019)による海面水温低下の解析

Abstract

Typhoons Faxai and Hagibis in 2019 caused severe damages over the eastern Japan islands. Although these two typhoons had relatively similar tracks with similar moving speed over the western North Pacific, but the amount of sea surface temperature (SST) decreases caused by the heavy winds associated with Faxai and Hagibis were quite different between two typhoons. Using ocean calculated it a high-resolution ocean model and meteorologic GPV data, we estimated the cooling parameter (Co) to evaluate the effect of the oceans and the typhoon characters on the SST decreases. This study applied Co to the real typhoon and found that Co and ΔSST are corresponding. Therefore, it is suggested that it is able to express ΔSST using Co. The correspondence between Co and ΔSST suggests that not only ocean conditions such as OHC and TCHP but also Typhoon characteristics are sufficiently important for ocean cooling associated with typhoon passage, since Co includes typhoon characteristics. In particular, the moving speed and the size of the typhoon. Therefore, we believe that Co is useful for estimating the SST decreases in a simple way, even if the target is a real typhoon.