新气候态下西南地区夏季气候变化特点及其成因  

Characteristics and Causes for Summer Climate Changes in Southwest China under the New Climate State

作　　者：唐红玉[1] 吴遥[1] 董新宁[1] 魏麟骁[1] TANG Hongyu;WU Yao;DONG Xinning;WEI Linxiao(Chongqing Climate Center,Chongqing 401147)

机构地区：[1]重庆市气候中心,重庆401147

出　　处：《气候与环境研究》2024年第1期45-58,共14页Climatic and Environmental Research

基　　金：重庆市自然科学基金面上项目CSTB2022NSCQ-MSX0558;中国气象局创新发展专项CXFZ2021Z011;中国气象局西南区域气象中心重大科研业务项目西南区域2014-1。

摘　　要：利用1981~2020年中国西南地区云南、贵州、四川、重庆393站气象观测台站夏季气温、降水和NCEP/NCAR再分析资料,分析了西南地区夏季气温、降水的气候值在新旧气候态下的不同特征和变化差异,并从大气环流影响角度,对变化成因进行了分析。结果表明:相对于旧气候态,新气候态下西南地区夏季降水总体呈略减少的变化,气温具有一致性变暖的变化特征。相对于旧气候态,新气候态下四川盆地东部降水的减少和云南北部、四川西部及贵州夏季降水的增多与西太平洋副热带高压的相对偏西偏北有关。同时中高纬阻高等系统的相对不活跃、贝加尔湖槽的减弱,对西南大部地区的暖干变化起到了积极作用。新气候态下,西南地区夏季贵州呈弱暖湿变化、而云南为较强的暖干变化、四川和重庆则呈强的暖干变化,这与西太平洋和印度洋地区水汽的变化密切相关。Using meteorological data from 393 observation stations in Yunnan,Guizhou,Sichuan,and Chongqing in Southwest China spanning from 1981 to 2020 in summer,alongside NCEP/NCAR reanalysis data in the same period,this study examines the distinct characteristics and variances in the climatological values of summer temperatures and precipitation in the Southwest China under different climatic states.Additionally,it delves into the analysis of causes for these variations from the perspective of atmospheric circulation.The results show that the summer temperature and precipitation values in Southwest China vary under the old and new climatic conditions.In addition,the summer precipitation in Southwest China is slightly reduced under the new climate state than that of the old one,and the temperature displays the characteristics of consistent warming.A decrease in precipitation in the eastern part of the Sichuan basin and an increase in summer precipitation in northern Yunnan,western Sichuan,and Guizhou are related to the west–northward shift of subtropical high pressure in the western Pacific Ocean.Meanwhile,the relative inactivity of high blocking systems at the middle and high latitudes and the weakening of the Baikal Trough play a positive role in the warm and dry changes experienced in most of the southwest region.Under the new climate regime,Guizhou shows weak warm–wet changes,Yunnan shows strong warm–dry changes,and Sichuan and Chongqing show strong warm–dry changes in summer.These changes are closely related to variations in water vapor level in the western Pacific and Indian Ocean regions.

关 键 词：新气候态 西南地区 夏季 成因 

分 类 号：P461[天文地球—大气科学及气象学]