中文摘要：

应用自动站雨量资料、常规观测资料和国家气象中心T213分析场资料,采用PSU/NCAR的高分辨率中尺度非静力数值模式MM5,模拟了2008年7月20日高原低涡东移引发的四川盆地暴雨过程。通过分析模式输出资料,结果得出高原涡东移影响四川盆地暴雨的一种物理触发机制：高原涡正涡度的东移促使四川盆地正涡度发展,正涡度的发展使得大气旋转上升加强,对流层高层强烈辐散,低层辐合,对流发展形成降水,大气凝结释放潜热加热大气,使得高层等压面升高,负涡度发展,低层降压,正涡度发展,这样就形成了一个正反馈的循环机制,从而导致了四川盆地强降水。

英文摘要：

Based on auto-weather station network data,conventional observation data and T213 analysis data,using the MM5 mesoscale numerical model and T213 reanalysis data,simulation was conducted the Plateau vortex rainstorm occurring in Sichuan basin on 20 July,2008.The simulated results show that： the Plateau vortex moving eastward promot the development of the positive vorticity over the Sichuan Basin,hence,the strong divergence at the tropospheric higher level and the convergence at the lower level are enhanced,and the convective precipitation may occur.The released latent heat of the precipitation may promote the development of the negative voritcity at the tropospheric higher level and the positive vorticity at the lower level.As a result,a positive feedback mechanism is forming,this feedback mechanism may support and maintain the vortex and the heavy rainfall over the Sichuan Basin.