Future changes in heavy rainfalls in Central Japan in long-term mega-ensemble climate projections

Abstract:

In this study, future changes in formation of heavy rainfalls (1 in 100 year probability rainfalls) in Central Japan (Gifu Prefecture) are compared using sea-level pressure distributions derived from the database called d4PDF including the 4-K warming future climate experiments (5,400 years) and historical climate experiments (3,000 years). According to principal component analysis and cluster analysis, the inverted sea-level pressure patterns in heavy rainfall events in d4PDF are classified into four categories: (A) frontal system I, (B) frontal system II, (C) low pressure system I and (D) low pressure system II. The averaged daily rainfalls in the future climate are greater in any category than those in the historical climate. It is considered that the heavy rainfalls in the future climate in Type A and Type D are intensified by the reinforcement of southern typhoons and the slowdown of early summer typhoons, respectively.