Changes in onset and withdrawal of the East Asian summer rainy season by multi-model global warming experiments

Baiu-Changma-Meiyu is a rainy period in early summer over East Asia (Japan, Korea and China) and its variability and change is one of the major focus in climate change projections in these areas. We analyze the changes in intensity and duration of Baiu-Changma-Meiyu rain by global warming using daily precipitation data of fifteen coupled atmosphere-ocean general circulation model (AOGCM) simula-tions under the SRES A1B scenario at the end of the twenty-first century. It is revealed that a delay in early summer rain withdrawal over the region extending from Taiwan, Ryukyu Islands to the south of Japan is contrasted with an earlier withdrawal over the Yangtze Basin, although the latter is not signif-icant due to inconsistent sign of changes among the models. Higher mean sea-level pressure anomalies in the tropical western Pacific in the future may be related to these late withdrawals. Changes in onset dates are relatively less compared to those in withdrawal dates. 1