夏季青藏高原东部热源异常与环流场和降水的关系

利用NCEP/NCAR再分析资料和中国160个站点的月平均降水资料,选取了2008年9月四川汶川地区特大暴雨实例,分析并验证了夏季青藏高原东部热源异常和中国局部降水异常的关系。结果表明:1夏季高原东部热源偏强会引起500h Pa风场能量偏大,其能量大值区与强降水区域分布相对应;2夏季高原东部热源偏强会引起南亚高压偏东偏强,从而引起西太副高西伸,使得水汽源源不断的向降水区域输送;3夏季高原东部热源异常时,通过加热场-高度场-降水场的同期及滞后效应,进一步影响到中国局部地区的降水异常。

Effect of summer heat anomaly in Eastern persistent heavy rain in Sichuan Basin

Using NCEP / NCAR reanalysis monthly and China 160 station average precipitation data, selected in September 2008 Wenchuan area rainstorm instance, analyze and verify the eastern Tibetan Plateau summer heat anomalies and abnormal relations between China local precipitation. The results showed that: (1) the eastern plateau summer heat can cause strong side 500hPa wind energy is too large, the energy value of the area with heavy rainfall large regional distribution is more uniform. (2) the eastern plateau summer heat can cause strong side of the South Asia High easterly stronger, causing WPSH westward extension, so that a steady stream of water vapor transport to the Sichuan Basin. (3) the eastern plateau during the summer heat anomaly, by heating field - height field - precipitation field over the same period and the lag effect, further affecting the precipitation in some areas of China exception.