基于RegCM4模式的我国西南地区极端降水变化预估研究  

Future changes in precipitation extremes over Southwest China based on RegCM4 model simulations

作　　者：刘博 陈活泼[2] 华维 LIU Bo;CHEN Huopo;HUA Wei(School of Atmospheric Sciences/Plateau Atmosphere and Environment Key Laboratory of Sichuan Province/Engineering Laboratory of Meteorological Disasters Prediction and Early Warning of Sichuan Province,Chengdu University of Information Technology,Chengdu 610225,China;Nansen-Zhu International Research Centre,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]成都信息工程大学大气科学学院/高原大气与环境四川省重点实验室/四川省气象灾害预测预警工程实验室,四川成都610225 [2]中国科学院大气物理研究所竺可桢-南森国际研究中心,北京100029

出　　处：《大气科学学报》2023年第2期180-192,共13页Transactions of Atmospheric Sciences

基　　金：中国科学院战略性先导科技专项(A类)资助(XDA23090102)。

摘　　要：基于5个全球气候系统模式结果驱动的高分辨率区域气候模式(RegCM4)模拟输出,系统评估了RegCM4模式对中国西南地区极端降水变化的模拟性能,并科学预估了中国西南地区极端降水的未来演变特征。结果表明,RegCM4模式能合理再现西南地区极端降水变化特征,但模拟的四川中部的湿偏差较大而四川盆地干偏差较大;进行偏差校正后,模拟性能有所提升,对西南地区极端降水模拟偏差有所减小。相较于当代气候(1986-2005年),就区域平均而言在21世纪(2021-2098年),有效降水总量(Prcptot)、强降水日数(R10 mm)、日最大降水量(Rx1day)和极端降水量(R95p)都明显增加;在RCP4.5和RCP8.5情景下,Rx1day和R95p在西南大部分地区增多,到21世纪末RCP4.5情景下增加幅度分别为16.0%和12.6%;Prcptot和R10 mm未来变化存在一定的区域差异,但Prcptot和R10 mm变化在空间上较为相似,在云南南部和四川盆地地区呈现减少趋势,其余地区增加明显;且RCP8.5高排放情景的变化幅度明显大于RCP4.5情景。Based on the outputs of the high-resolution regional climate model(RegCM4)driven by the results of five global climate system models,the simulation performance of RegCM4 for precipitation extremes in Southwest China is systematically evaluated.Furthermore,the future precipitation extremes in Southwest China are also evaluated.The results indicate that the RegCM4 models can reasonably reproduce the climate means for the period from 1986 to 2005,but there are greater biases over Southwest China,especially over central Sichuan and the Sichuan basin.Thus,bias correction is implemented on the RegCM4 outputs,and it can significantly reduce the bias of precipitation extremes over Southwest China.For future changes in precipitation extremes,the total wet day precipitation(Prcptot),very heavy precipitation days(R10mm),maximum day precipitation(Rx1day),and extreme precipitation(R95p)are projected to increase significantly across Southwest China over the 21st century under the representative concentration pathways(RCP)4.5 and 8.5 scenarios.Compared to the current climate(1986—2005),all the precipitation extreme indices exhibit an increasing trend in the future.Both Rx1day and R95p are projected to increase in most areas of Southwest China under the scenarios of RCP4.5 and RCP8.5 in the 21st century,and are reported to respectively increase by approximately 16.0%and 12.6%at the end of the 21st century under the RCP4.5 scenario.The future changes in Prcptot and R10mm show great regionality,with both showing a decreasing trend in southern Yunnan and the Sichuan Basin,while the other regions show an increasing trend.Additionally,these changes in Prcptot and R10mm under the RCP8.5 scenario are considerably higher than those under the RCP4.5 scenario.

关 键 词：RegCM4 西南地区 极端降水 评估 预估 

分 类 号：P426.614[天文地球—大气科学及气象学]