21世纪以来西南地区干季降水与西太平洋副热带高压年代际变化的关系  

Relationship Between the Dry-Season Precipitation in Southwest China and Decadal Changes of the Western Pacific Subtropical High Since the 21st Century

作　　者：蒋薇 张祖强[2] 刘芸芸[2,3] JIANG Wei ZHANG Zuqiang LIU Yunyun(Jiangsu Climate Centre, Nanjing 210008 National Climate Centre, Beijing 100081 Collaborative Innovation Centre on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology, Nanjing 210044)

机构地区：[1]江苏省气候中心,南京210008 [2]国家气候中心,北京100081 [3]南京信息工程大学气象灾害预报预警与评估协同创新中心,南京210044

出　　处：《气象》2016年第11期1335-1341,共7页Meteorological Monthly

基　　金：国家重点基础研究发展计划(973计划)(2013CB430200);江苏省气象科研开放基金项目(KZ201505);公益性行业(气象)科研专项(GYHY201206017)共同资助

摘　　要：利用1961-2011年观测资料分析了西南地区干季(11月至次年4月)降水的变化特征,发现西南地区干季降水在2000年前后发生了年代际尺度的转折,其前后降水空间分布呈现相反的分布特征,特别是21世纪以来降水显著偏少,干旱加剧,降水量显著减少的区域主要在云南大部及其周边地区。西南干季降水和西太平洋副热带高压的负相关在20世纪90年代后期明显加强,而21世纪以来副热带高压表现出明显的年代际增强,即面积增大、强度增强、西伸脊点位置偏西。西南干季降水与副热带高压关系的增强,以及副热带高压本身的年代际增强,对西南干季降水减少造成显著的影响,是西南干旱加剧的可能原因。The variation characteristics of precipitation in the dry season （from November to the following April） in the Southwest of China are investigated by using the observation data from 1961 to 2011. The results indicated that the precipitation during the dry season changed remarkably around 2000. The spatial distribution characteristics of the precipitation before 2000 was distinctively different from the characteristics after 2000. The rain was much less than normal and drought got worsened in the 21st century. Precipitation in Yunnan and its surrounding areas reduced significantly. The negative correlation between the rain of the dry season in Southwest and the western Pacific subtropical high （WPSH） strengthened rapidly in late 1990s. Meanwhile the feature of WPSH has shown markedly decadal enhancement since the 21st century. Its area has been growing, with intensity enhancing and position being farther western than normal. Enhancement of the relation between the rainfall during the dry season and WPSH and the decadal enhancementof WPSH, both contribute remarkably to the decline of the dry season rainfall, and probably result in the frequent drought in the Southwest of China.

关 键 词：西南地区 干季降水 西太平洋副热带高压 年代际 

分 类 号：P466[天文地球—大气科学及气象学]