对称不稳定对梅雨锋暴雨影响的数值模拟

在Kuo-Anthes垂直对流参数化方案和Nordeng倾斜对流参数化方案基础上,提出了垂直-倾斜对流一体化参数化方案,在引入MM5模式后,对1999年6月发生在长江流域的一次大尺度带状强降水过程进行了数值模拟及敏感性试验。结果表明:在模式中引入倾斜对流参数化方案,可有效改进模式模拟的降水强度和位置,加快形成锋面附近的垂直环流并使之得到增强,模拟结果更接近实况。同时也表明,在模拟和预报具有对称不稳定的天气系统时,在模式中考虑倾斜对流参数化方案是必要的。

Numerical simulation of symmetric instability on Meiyu front torrential rain

A ccordiy to the Kuo-Anthes vertical convection and Nordeng slantwise convection parameterization scheme, a vertical-slantwise convection integrated parameterization scheme is designed and introduced into the MM 5 model.Using the integrated scheme, a process of large scale strong precipitation in the Yangtze River Basin in June 1999 is smiulated and tested sensitively.Results show that the intensity and location of precipitation are improved effectively, the vertical circulation forms quickly and intensifies, and the simulated result is close to the observation when the slantwise convective param eterization is introduced into MM 5.The result illustrates the necessity of considering the slantwise convention in torrential rain smiulations for the symmetric instability weather system.