皖南冬半年云系和降水与东亚环流结构分析

用皖南5个气象站2001-2004年冬半年地面气象观测资料、美国NCEP/NCAR全球日平均分析场资料和历史天气图,对皖南冬半年云系和降水与大尺度大气环流进行了分析.主要结果如下:华北低槽型出现次数较多,平均云量接近最大值,平均降水量最大(5.7mm),平均云量和降水量南部略偏多.沿海低槽型出现次数最多(33.1%),平均云量(2.7、4.3成)和降水量(2.0mm)均最小,平均降水量自北向南逐渐增多.大陆高压(脊)型出现次数偏少,平均云量和降水量接近最小值,平均低云量和降水量南部偏多.南支低槽型出现次数较多,西南部平均云量和降水量偏多.西北低槽型平均云量最多(4.8、7.5成),平均降水量东部偏小.纬向环流型出现次数较少,平均云量居中等;平均降水偏小,南部略多.

Cloud System and Precipitation in Southern Anhui Province in Winter Half Year and Structure Analysis of East Asian Circulation

Based on the five station data in Southern Anhui Province and NCEP/NCAR reanalysis data and historical weather map from 2001 to 2004,the relationship between cloud system and precipitation in Southern Anhui Province in winter half year and East Asian Circulation are analyzed.The results are as follows.The more number of North China Trough are appeared,the mean cloud fraction is in proximity to the largest value,the most of precipitation.The most number of Southeast Coast Trough are appeared,the mean cloud fraction and the precipitation are least.Continental Anticyclone is lesser in comparison with others,the mean cloud fraction and precipitation is in proximity to the least.The more number of South China Trough are appeared,the more cloud fraction and the precipitation in Southwest.The most mean cloud fraction about Northwest China Trough,the precipitation are lesser in the East.The lesser number of Zonal Circulation are appeared,the medium mean cloud fraction and the lesser mean precipitation.