Projections on Regional Climate and Compound Events in East Asia Based on QDM-Corrected Multiple High-Resolution CORDEX Simulations

Following the Coordinated Regional Downscaling Experiment East Asia Phase II (CORDEX-EA-II) setting, two regional climate models (RCMs) driven by four global climate models (GCMs) have been used to provide climate change information on surface air temperature and daily precipitation. A trend-preserving bias correction method, quantile delta mapping (QDM), is first validated for the historical period of 1981–2005 and then applied to the future period of 2040–2060 under the Representative Concentration Pathway (RCP) 8.5 scenarios. Results show that QDM is competent in correcting model biases on temperature, precipitation and compound events (CEs, defined as the concurrent occurrence of temperature and precipitation anomalies) for both spatial distributions and annual cycles. For future assessments, a widespread warming is projected over the region, with average temperature changes higher than 1.6°C. Changes in precipitation are more region-variated. Increased precipitation is most significant in the northwestern part of the CORDEX-EA region, and some models also present a decreased precipitation in southeastern China. Climate changes on CEs correspond with the effect of global warming; RCMs present a significant increase in the frequency of hot CEs and an obvious decrease in cold-dry CEs. These results are expected to be useful for future climate assessments and for better understanding of the bias correction technique under climate change situations.