5月青藏高原地区感热异常对北疆夏季降水的影响  

Impact of the Anomaly of Surface Sensible Heat in Qinghai-Xizang Plateau and Its Surrounding Areas on Summertime Precipitation in Northern Xinjiang

作　　者：赵勇[1] 李如琦 杨霞 何冬燕[3] 张超 

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [2]新疆维吾尔自治区气象台,新疆乌鲁木齐830002 [3]安徽省气候中心,安徽合肥230031

出　　处：《高原气象》2013年第5期1215-1223,共9页Plateau Meteorology

基　　金：国家自然科学基金项目(41005050;41175086);国家重点基础研究发展计划(2010CB951001);新疆气象局科技项目(200937)

摘　　要：利用NCEP/NCAR月平均再分析资料和北疆43个气象站降水资料,分析了1961-2010年5月青藏高原地区地表感热异常与北疆夏季降水的关系。结果表明,青藏高原主体及其东、西部(以90°E为界)地表感热与北疆夏季降水的关系有所不同,以青藏高原东部关系最优。当5月青藏高原感热偏弱、其西北侧沙漠感热偏强时,南亚高压呈双体型分布,500hPa中亚和贝加尔湖上空分别受异常气旋和反气旋控制,新疆上空盛行异常偏南风,有利于低纬度暖湿气流北上。同时,越赤道索马里急流加强,阿拉伯海上空为异常反气旋控制,低纬水汽向北输送加强,导致更多的北疆夏季降水;反之亦然。As well known, the surface thermal anomaly （STA） in the Qinghai-Xizang Plateau （QXP） have important influences on the climate in China. Previous studies were focused on the effects of the STA on the weather and climate in eastern monsoon regions, less attention was paid to the connection between the STA and the precipitation in arid regions, especially in Xinjiang. In this paper, the preliminary results of the relationship between the STA in QXP and summer rainfall in northern Xinjiang were given. Using the NCEP/NCAR reanalysis monthly mean data and precipitation data at 43 stations in northern Xinjiang, the relationships between the anomaly of surface sensible heat （SH） in QXP and its surrounding areas and the summer precipitation in northern Xinjiang were analyzed. The results showed the effects of the SH in the QXP, eastern QXP and western QXP （divided along 90~E） on the summer time precipitation are different and the SH in eastern QXP have the most closed relation with summer precipitation. When the SH weak- ened in QXP and strengthened on the northwest side of the QXP, the South Asia High has two positive centers, which is one of the most important circulation patterns for occurring more summer rainfall in northern Xinjiang, and there are an anomalous cyclone over central Asia and an anomalous anticyclone over the Baikal Lake, respectively, which results in the anomalous south wind prevailing and is favorable to the warm-wet air move from the low latitude regions. In addition, the transportation of water vapor by Soma- lia jet is unusually strong, passing over the Equator, and at the same time the Arabian Sea is controlled by anomalous anticyclone circulation, driving the water vapor to be transferred continuously to the central A- sia and Xinjiang, so the south water vapor channel which impacted Xinjiang is strengthened significantly. Above all are contributed to the occurrence of more summer precipitation in northern Xinjiang, and vice versa.

关 键 词：青藏高原 地表感热 热力空间差异 北疆夏季降水 

分 类 号：P461.3[天文地球—大气科学及气象学]