西太平洋暖池混合层热力异常与我国东部夏季降水的关系  

THE RELATIONSHIP BETWEEN THE THERMAL ANOMALY OF THE MIXED LAYER OVER THE WESTERN PACIFIC WARM POOL AND THE PRECIPITATION OF EASTERN CHINA IN SUMMER

作　　者：张良瑜 王黎娟[1] 韩世茹 葛静[1] 

机构地区：[1]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,气象灾害教育部重点实验室,江苏南京210044

出　　处：《热带气象学报》2015年第3期355-363,共9页Journal of Tropical Meteorology

基　　金：国家重点基础研究发展计划(2012CB417403);江苏省自然科学基金项目(BK20131432);江苏省高校自然科学研究重大项目(14KJA170004);江苏省“青蓝工程”共同资助

摘　　要：利用1981-2012年GODAS（Global Ocean Data Assimilation System）月平均次表层海温资料、混合层深度资料、NCEP／NCAR再分析资料及中国756个站的逐日降水资料，分析西太平洋暖池混合层热力异常与中国东部夏季降水的关系及可能的影响途径。结果表明，前期5月是西太平洋暖池（125～150°E，0-18°N）混合层热力异常影响我国东部夏季降水的关键期。在前期5月西太平洋暖池异常偏暖（冷）年，长江中下游流域的夏季降水偏少（多），黄河中下游流域夏季降水偏多（少）。1991-2012年，5月的西太平洋暖池热力异常呈现明显的变化趋势，由异常偏冷期向偏暖期转变。机制分析表明，由于前期5月西太平洋暖池热力异常，引起夏季菲律宾附近及其以东洋面和印度半岛中北部上空的对流活动、西太平洋副热带高压（简称副高）和南亚高压位置及强度的异常，进而影响水汽输送及上升运动，最终导致我国东部夏季降水的异常分布。The relationship between the thermal anomaly of the mixed layer over the western Pacific warm pool （WPWP） and the precipitation of eastern China in summer and a possible influence channel are analyzed by using the GODAS （Global Ocean Data Assimilation System） monthly mean sub-surface sea temperature data, monthly mean mixed layer depth data, NCEP/NCAR reanalysis dataset, and daily precipitation data from 756 stations in China from 1981 to 2012. The results show that the thermal anomaly of the mixed layer over the key area （125-150°E,0-18°N） of the WPWP in the preceding May is essential to the precipitation of eastern China in summer. When the thermal condition of the mixed layer over the key area of the WPWP in the preceding May is warmer （cooler）, the precipitation of the following summer is less （more） in the middle and lower reaches of the Yangtze River basin and more （less） in the middle and lower reaches of the Yellow River basin. From 1991 to 2012, the thermal anomaly of the mixed layer over the key area of the WPWP in May presents an obvious variation trend from cold to warm anomaly. Anomalous water vapor transport and vertical motion in summer are caused by location and intensity anomaly of convection activity over the ocean near and east of the Philippines, western Pacific subtropical high and South Asia high, which are generated by the thermal anomaly of the mixed layer of the WPWP in the preceding May, and further induce the precipitation anomaly of eastern China in summer.

关 键 词：西太平洋暖池 混合层 夏季降水 副高 

分 类 号：P426.6[天文地球—大气科学及气象学]