Reproducibility and Future Projections of the Precipitation Structure in East Asia in Four Chinese GCMs That Participated in the CMIP5 Experiments

Under the current global warming tendency, precipitation change is characterized by either a change in the amount of total rainfall or a shift in the precipitation structure.Due to lack of access to high-resolution data for the daily rainfall of the entire East Asian region, previous studies in East Asia mainly focused on spatial-temporal variations in precipitation amounts rather than its structure.Based on the latest daily precipitation APHRODITE (Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation) data and the outputs of four Chinese CMIP5 (Coupled Model Intercomparison Project Phase 5) models (BCC-CSM1-1, BNU-ESM, FGOALS-g2, and FGOALS-s2), the authors investigated the characteristics of precipitation structures in East Asia.The authors also examined future projections made by these models.The results indicate that the amount of climatological rainfall observed reaches a maximum at the intermediate range and tails off toward the high and low rain rates.With respect to frequency, a rate of 1 mm/d occurs far more frequently than any other rain rates.More (less) light (moderate) rain occurs in the north than in the south.Extreme heavy precipitation mainly occurs on the southeast coast of China and south of Japan.With respect to the long-term trend, light rain and heavy rain (>30 mm/d) increase while moderate rain decreases.The climatology of the precipitation structure in East Asia is adequately reproduced by all four models.BCC-CSM1-1 and FGOALS-g2 can reproduce the rainfall trends of all the rain rate types.FGOALS-s2 and BNU-ESM cannot reproduce the downward trend of moderate rain.Based on projections by the four models, heavy rain (>30 mm/d) will increase under global warming.The higher the extreme heavy rain, the more significant the increasing trend.Light (moderate) rain will increase (decrease) in the south and decrease (increase) in the north as global warming progresses.Further analysis indicates that the increase in extreme heavy rain is mainly due to rise in the global mean air temperature.