[A-CG30] Extratropical oceans and atmosphere

[ACG30-P06] Future changes of tropical cyclone-induced precipitation distribution around Kyushu Islands in dynamically downscaled large-ensemble simulations

Shuhei Yamaguchi¹, *Takashi Mochizuki¹, Ryuichi Kawamura¹, Tetsuya Kawano¹ (1.Department of Earth and Planetary Sciences, Kyushu University)

Keywords:global warming, tropical cyclone, dynamical downscaling

By using a large-ensemble set of 5-km resolution (SI-CAT DDS5TK) simulations dynamically downscaled from 20-km resolution (d4PDF-RCM) simulations, we define statistical changes in precipitation distribution around Kyushu Island associated with tropical cyclone attacks in future. The d4PDF-RCM represents the enhancement in intensity and decrease of the numbers of the tropical cyclone over the Northwesten Pacific. The precipitation amount is increased near the center of the individual tropical cyclone. In contrast, the SI-CAT DDS5TK can represent detailed spatial patterns of rainfall changes rather than uniform increase, particularly due to potential influences of the finer-resolved topography. When focusing on the east coast of Kyushu Island where the tropical cyclone attack is a major factor to control the rainfall changes in future, the tropical cyclone works to reduce the rainfall through the southward shift of the moisture flux convergence. The rainfall is enhanced at the sea surface of the southeast of the Kyushu Island, probably because the tropical cyclone moves more slowly, its lifetime becomes longer and hence a chance of attack of relatively weak cyclones can be increased in the extratropical area.