广东秋冬春连旱的时空变化及环流演变特征  

SPATIAL-TEMPORAL DISTRIBUTION AND CIRCULATION EVOLUTION OF DROUGHT FROM AUTUMN TO SPRING IN GUANGDONG

作　　者：梁巧倩[1] 梁玉琼[1] 纪忠萍[1] 吴秀兰[1] 李茵茵[1] 

机构地区：[1]广州中心气象台,广东广州510080

出　　处：《热带气象学报》2009年第1期123-128,共6页Journal of Tropical Meteorology

基　　金：广东省科技三项经费计划项目(2006A36503001);广东省科技计划项目(2007A032600002);广东省气象局气象科研课题(200519)共同资助

摘　　要：利用1948—2006年NCEP/NCAR的再分析高空资料以及广东省48个测站的降水资料,综合采用L指数和AWTP指数可对广东秋冬春连旱进行较好的描述;EOF的分析表明广东的秋冬春连旱空间变化具有全省一致性,时间上不仅具有明显的年际变化,还有阶段性变化和趋旱的趋势变化。广东秋冬春连旱异常年份的合成分析表明,从秋季到次年春季,极涡和南支槽的活动都较常年偏弱;秋季华南受偏强的反气旋环流影响,干燥少雨;冬季,小股的冷空气偏东路径活动,低层华南到南海大部有东北风距平,干燥少雨;春季,小股的冷空气频繁东移,华南处高空槽底偏西风场中,低层的西南风较常年偏弱,不利于华南地区冷暖气流的交汇,降水偏少。这些分析结果可为短期气候预测提供依据。By using the NCEP/NCAR reanalysis pressure data, 48-station observational precipitation data, and methods of EOF and composition, spatial-temporal distribution and circulation evolution of drought from autumn to spring in Guangdong are studied. The results are presented as follows. The combination of L index and AWTP（average waiting time of precipitation） index can well describe the drought from autumn to spring in Guangdong. The first mode of EOF analysis has an identical signal in Guangdong with significant inter-annual and inter-decadal variation. From autumn to spring in the drought cases, the polar cyclone and southern branch trough are weaker. In autumn, under strong anticyclonic circulation, it is much dry and there is less rainfall over South China. In winter, the cold air moves more to the east than usual; it is much dry and there is less rainfall with the northeast anomaly wind over South China and South China Sea at 850 hPa. In spring, cold air is still active, and moves east, but cold and warm airflow converge less in South China, and then rainfall is much less than average. These results will help short-range prediction.

关 键 词：环流演变 统计 秋冬春连旱 时空分布 

分 类 号：P426.616[天文地球—大气科学及气象学]