前冬澳大利亚周边海温与我国长江流域夏季降水的联系  

The Relationship Between Prior-winter SST around Austria and Summer Rainfall in the Yangtze River Valley of China

作　　者：董祝雷 任保华[1] 郑建秋[1] 卢国阳[1] 徐迪[1] 

机构地区：[1]中国科学技术大学,合肥230026

出　　处：《大气科学》2016年第6期1273-1283,共11页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展计划项目2012CB417403;中国科学院战略性先导科技专项--过去百年气候增暖及成因XDA05090402;中国科学院南海海洋研究所热带海洋环境国家重点实验室课题LTO1502~~

摘　　要：利用1980~2012年Hadley中心的Had ISST再分析海温资料、美国NCEP/NCAR月平均再分析资料和中国160站月平均降水资料,研究了前冬澳大利亚周边海温与长江流域夏季降水关系。研究表明,澳大利亚周边冬季逐月海表温度距平（SSTA）EOF分解第一模态具有全区一致模形式,澳大利亚周边海温一致模具有季节持续性,可从前一年冬季一直维持到当年的夏季。用Ni？o3.4指数剔除海温场中ENSO线性信号后,表明澳大利亚周边海温一致模可能是独立于ENSO位相的区域局地现象。基于冬季澳大利亚周边海温一致模形式,定义了表征长江流域夏季降水一致模指数（CMI）,对长江流域夏季降水具有一定的短期预测意义。澳大利亚周边海温一致模与长江流域夏季降水显著相关,一方面是因为澳大利亚周边海温异常能激发南北半球遥相关,造成西太平洋副热带高压异常,从而影响长江流域夏季降水;另一方面,澳大利亚周边海温异常导致热带地区南北半球对流异常,尤其使得菲律宾周边地区的对流活动异常,进而造成长江流域夏季降水异常。The Had ISST（Hadley Centre Global Sea Ice and Sea Surface Temperature） dataset, the NCEP/NCAR（National Centers for Environment Prediction/National Center for Atmospheric Research） monthly reanalysis data, and monthly precipitation data collected at 160 stations in China's Mainland from 1980 to 2012 are used to study the relationship between the summer rainfall over Yangtze River valley in China and the prior-winter Sea Surface Temperature Anomalies（SSTA） around Austria. Results show that the leading mode of the monthly SSTA around Austria revealed by the Empirical Orthogonal Function（EOF） analysis exhibits the characteristics of consistent SST variationtrend over the entire region, and the SSTA around Austria has a seasonal continuity, which can persist from the prior-winter through the following summer. Analysis of the Ni？o3.4 index with the ENSO linear signal removed in the SST field shows that the consistent mode may be a local phenomenon that is independent of ENSO events. Based on the consistent mode of prior-winter SSTA around Austria, the Consistent Mode Index（CMI） is defined to characterize the influence of SSTA around Austria on the summer rainfall in the Yangtze River valley. The CMI has certain implications for short-term forecast of summer precipitation in the Yangtze River valley. The prior-winter SSTA around Austria may affect East Asian summer atmospheric circulations in two ways. First, the prior-winter SSTA signal around Australia can persist through the following summer and trigger a teleconnection wave train between the Northern and Southern Hemispheres, leading to an abnormal West Pacific Subtropical High（WPSH） that subsequently affects the summer precipitation in the Yangtze River valley. Second, the SSTA around Australia can result in abnormal convections in the tropics in both hemispheres, especially abnormal convection activities over the Philippine Sea, and eventually lead to anomalous changes in summer rainfall in the Yangtze River valley.

关 键 词：澳大利亚周边海温 长江流域 夏季降水 一致模指数 热带对流 

分 类 号：P426.616[天文地球—大气科学及气象学]