[A-AS08] General Meteorology

[AAS08-11] Effects of ocean prediction for heavy rainfall prediction

★Invited Papers

*Yuya Baba¹ (1.Japan Agency for Marine-Earth Science and Technology)

Keywords:heavy rainfall prediction, ocean prediction, air-sea interaction

Frequency and intensity of heavy rainfall over Japan are increasing along with the progress of global warming. To avoid the wind and flooding damage by the heavy rainfall, more earlier heavy rainfall prediction is required. The heavy rainfall frequently occurred in summertime in Japan. The source of heavy rainfall, i.e., water vapor comes from the southwest of Japan following the pressure pattern formed around Japan. Thus, prediction of the pressure pattern is necessary to realize the early heavy rainfall prediction. The pressure pattern is determined not only by atmosphere but also ocean, so ocean prediction is ideally needed for the prediction. This study examined the effects of ocean prediction by using atmospheric and coupled models and conducting hindcast experiments for several summertime heavy rainfall events. The results show that the coupled model is superior to the atmospheric model in all events. The coupled model can consider air-sea coupling correctly so it can prediction Pacific high well, but the atmospheric model can not consider it, leading to failure in predicting the Pacific high and resulting heavy rainfall. Although the prediction model becomes complicated and computational cost increases, the ocean prediction is considered useful to realize earlier heavy rainfall prediction.