基于多区域模式集合的中国西部干旱区极端温度未来预估

Extreme temperature projection over northwestern China based on multiple regional climate models

利用CORDEX-EA计划11个区域模式模拟结果,集合预估了中国西部干旱区16个极端温度指数未来的变化趋势及空间分布。结果表明:1)区域模式基本上能够再现近30 a西部干旱区极端温度的空间分布。2)多模式集合预估的西部干旱区21世纪中期霜冻日数(FD)和冰封日数(ID)呈现显著的下降趋势,而热夜日数(TR)和夏季日数(SU)则呈现明显的上升趋势。3)未来异常暖昼持续指数(WSDI)和生长期(GSL)呈现增加趋势,异常冷昼持续指数(CSDI)和日较差(DTR)则呈现下降趋势。4)未来气候增温导致冷昼日数(TX90p)、暖夜日数(TN90p)增加,而暖昼日数(TX10p)和冷夜日数(TN10p)减少。5)未来月最高温度极大值(TXx)、月最低温度极大值(TNx)、月最高温度极小值(TXn)和月最低温度极小值(TNn)都呈现增加的趋势。因此,西部干旱区未来发生极端低温事件的概率减小,发生极端高温事件的概率则会增大,但不同的极端温度指数变化的空间分布并不均一,存在明显的区域差异。

In this study,the spatial and temporal changes of future extreme temperature over northwestern China was evaluated using 11 regional climate models in the context of the Coordinated Regional Climate Downscaling Experiment for East Asia (CORDEX-EA) project.The main findings are as follows:1) The regional climate models could reproduce the spatial distribution of extreme temperature over northwestern China.2) The multi-model ensembles indicate that the FD and ID will decrease,while the TR and SU will increase in the 21st century over northwestern China.3) The WSDI and GSL of northwestern China show increasing trend,while the CSDI and DTR show decreasing trend in the 21st century.4) Due to the increase of temperature,TX90p and TN90p will increase,while TX10p and TN10p will decrease in the future.5) TXx,TNx,TXn and TNn show an increasing trend in the 21st century.Therefore,in the future,the probability of cold extreme events will decrease,and the probability of warm extreme events will increase,along with distinct spatial heterogeneity.