【摘要】 采用1961—2015年NCEP/NCAR再分析资料和华南地区降水资料,分析了7—9月亚洲-太平洋涛动(APO)与热带西太平洋环流系统以及垂直运动、水汽输送等条件的关系,探讨了其与华南7—9月汛期强度的联系机制.研究表明:(1)7—9月APO强度的年际变化与同期华南降水雨强存在显著负相关,即APO偏强(弱)年华南汛期少(多)雨.(2)在APO偏强(弱)年,副高偏北偏东(偏南偏西),副高南侧偏东气流减弱(加强),不(有)利于热带气旋西行影响华南,华南易少(多)雨.(3)在APO偏强(弱)年,东亚副热带夏季风偏强(弱),冷空气偏北偏弱(偏南偏强),不(有)利于华南及近海的热带气旋发展,华南易少(多)雨.(4)在APO偏强(弱)年,热带西太平洋纬向风垂直切变明显增大(减小),垂直上升运动减弱(加强),不(有)利于热带气旋的生成,且热带西太平洋水汽条件易使得热带气旋偏北偏东(偏南偏西)生成,华南易少(多)受热带气旋影响和少(多)雨.更多还原

【Abstract】 The NCEP/NCAR reanalysis in 1961—2015 and precipitation data in South China are utilized to analyze the correlation between Asia Pacific Oscillation(APO)in flood season in South China and the circulation situation in the tropical Western Pacific,and convection conditions,and moisture conditions,along with a further discussion of the relation mechanism between the APO and the precipitation in South China.The results show that:(1)the correlation between interannual variation of summer APO intensity and precipitation intensity during the same period in South China is significantly negatively.The higher(lower)APO,the less(more)precipitation in summer in Southern China.(2)The APO is high(low),subtropical anticyclone comes Northward and Eastward(Southward and Westward),the weak(strong)easterly flow in the south of subtropical anticyclone is inadvantageous(advantageous)for tropical cyclones going Westward,so that the South China is rainless(rainy).(3)The APOis high(low),thesubtropical summer monsoon in East Asian is stronger(weaker),the old air goes north goes weaker(southstronger),is inadvantageous(advantageous)for the formation of tropical cyclone in Southern China and offshore,so that the South China is rainless(rainy).(4)In the high(low)years of APO,the vertical shear of zonal wind in the tropical Western Pacific increase(decrease)signficantly,and the upward motion is weak(strong),which is unconducive to the formation of tropical cyclones.(5)The APO is high(low),the tropical cyclone in the tropical Western Pacific goes North and East,the north(south)part of coastal areas are more sensitive,so that the South China is rainless(rainy).更多还原