与前期秋冬季热带对流活动异常相关联的东亚冬春季大气环流及山东4月降水

PREVIOUS CONVECTION ANOMALY IN AUTUMN AND WINTER ASSOCIATED WITH THE GENERAL CIRCULATION OVER EAST ASIA IN WINTER AND SPRING AND APRIL PRECIPITATION IN SHANDONG

关键词:  热带对流活动  东亚大气环流  山东4月降水

Key words:  Convection over Tropics  General Circulation over East Asia  April Precipitation in Shandong

摘要:

利用1979～2006年月平均OLR、850hPa、200hPa风场等资料,分析了山东4月降水异常年的前期秋、冬季热带地区对流活动特征,发现前冬12月的热带西太平洋地区对流活动异常与山东4月降水的关系最为密切,进一步分析其与东亚大气环流关系,结果表明西太平洋暖池上空的对流活动异常与冬春季东亚大槽、东亚局地的Hadley环流以及Walker环流的强弱紧密相连,且对流活动强(弱)年相伴随的东亚大气环流异常特征恰与山东4月降水异常少(多)年的特征相吻合,因此,12月热带西太平洋对流活动强弱可作为山东4月降水预测的一条重要依据。

Abstract:

Using OLR and 850 hPa and 200 hPa wind fields data(1979～2006),the characteristics of previous convection over the tropical area in Autumn and Winter of April precipitation anomaly in Shandong are diagnosed.The main conclusions are as follows.Previous convection anomaly over the Western Pacific Warm Pool in December has close relationship with the April precipitation in Shandong.Further analysis of the relationship of convection with the general circulation over the East Asia shows that the convection anomaly over the Western Pacific Warm Pool has close relationship with the East Asian Trough,the Hadley cell over East Asia and the Walker cell.The characteristics of East Asian atmospheric circulation accompanied by stronger(weaker) convection are identical to that accompanied by less(more) April precipitation in Shandong.Therefore,the convection anomaly over the tropics in December may be an important basis for April precipitation in Shandong.