气候模式对东北三省降水模拟能力评估及预估

摘要

利用CMIP 5全球气候模式、RegCM 4区域气候模式数据集和中国东北三省162个气象站降水观测资料，评估了CMIP 5和RegCM 4模式对中国东北三省降水的模拟能力，并对RCP 4.5和RCP 8.5温室气体排放情景下东北三省未来降水的变化进行了预估。结果表明：CMIP 5和RegCM 4模式均能较好地模拟东北三省年及四季降水量的变化，可再现东北三省降水量由东南向西向北递减的空间分布形势，但模拟的降水中心偏北，模拟的降水强度偏强；两个模式对夏季降水的模拟优于冬季，对冬季降水的模拟存在较大偏差。总体而言，全球气候模式CMIP 5对东北三省降水的模拟结果较好。对东北三省降水量的预估表明，在RCP 4.5和RCP 8.5情景下，全球气候模式CMIP 5预估东北三省年和四季降水量均呈不同程度的增加，其中对冬季降水量预估的偏差百分率增幅最大。在RCP 8.5情景下，东北三省降水量增幅显著，预估未来东北三省降水增加量基本呈由南向北逐步递减的分布，降水偏差百分率基本呈由西南向东北递减的分布。在RCP 4.5情景下，东北三省降水量增幅较小，预估未来东北三省降水量总体呈由东南向西北递减的分布，降水偏差百分率基本呈由西向东递减的分布。%Based on datasets from global climate model CMIP 5 (Coupled Model Intercomparison Project Phase 5 ) and regional climate model RegCM 4 (Regional Climate Model 4),as well as precipitation data from 162 meteoro-logical stations in Northeast China (NEC),the capability to simulate precipitation by CMIP 5 and RegCM 4 was e-valuated.Additionally,precipitation changes in NEC in the future were predicted and assessed using these two models under two greenhouse gas emission scenarios,i.e.RCP (Representative Concentration Pathways)4.5 and RCP 8.5 .The results show that these two models can well simulate annual and seasonal precipitation in NEC.The spatial distributions of precipitation,which gradually decreasing from southeast to northwest in NEC,are well re-produced by the two models.The simulated precipitation center lies in the north of observed position,and precipita-tion intensity is stronger than that of observations.The simulated precipitation in summer is more accurate than that in winter and precipitation deviation in winter is much larger.Overall,simulated results of precipitation in NEC by CMIP 5 are better.The prediction results of future precipitation show that annual and seasonal precipitation in NEC simulated by CMIP 5 increases under emission scenarios of RCP 4.5 and RCP 8.5 .The precipitation deviation per-centage in winter is larger than that in other seasons.Under emission scenario of RCP 8.5 ,precipitation′s incre-ments in NEC are significant.The spatial distribution of precipitation increments decreases from south to north,and precipitation deviation percentages decrease from southwest to northeast.Under emission scenario of RCP 4.5 ,pre-cipitation increments are less.The spatial distribution of predicted precipitation decreases from southeast to north-west,and precipitation deviation percentages decrease from west to east.