領域気候モデルとd4PDFを用いた梅雨豪雨の将来変化に関するマルチスケール解析

Abstract

Baiu heavy rainfall is a phenomenon in the small meso-β scale under atmospheric circumstances of a Baiu front in the relatively large meso-α and macro scale. Thus we captured Baiu heavy rainfall from multiple spatial scales and estimated their detailed future change. For multiscale analysis in our study, we mainly used NHRCM05 which is a regional climate model in the high resolution of 5km, and d4PDF20, which has a huge ensemble member in a coarser resolution of 20km. The results show that the risk of Baiu heavy rainfall may increase in the Northern Japan and Japan Sea side area, where have seldom experienced Baiu heavy rainfall in the current climate, as the increasing trend of atmospheric patterns prone to heavy rainfall is proven to be significant. On the other hand, in the Pacific side area, the mechanism of Baiu heavy rainfall may also change in the future. Moreover, the increasing trend of accumulated rainfall amount of Baiu heavy rainfall can also be found.