中尺度模式中各种积云参数化方案的对比试验

Contrast Experiments of a Torrential Rain Event Using Four Cumulus Convection Parameterization Schemes

利用非静力中尺度MM5数值模式,选择Anthes-Kuo、Grell、Kain-Fritsch和Betts-M iller 4种积云对流参数化方案,对2003年7月25—26日台风登陆减弱为中尺度低压系统后影响云南产生的强降水过程进行模拟试验,重点分析了4种参数化方案模拟的降水分布、降水强度和中尺度低压的流场特征。结果表明:4种积云参数化方案对这次强降水过程均有一定的模拟能力,能够很好地模拟过程强降水中心的位置,但Grell、Kain-Fritsch和Betts-M iller 3种方案模拟的大雨范围比实况大雨范围明显偏小,Betts-M iller方案模拟的降水强度比实况偏大,Anthes-Kuo方案的模拟结果与实况比较接近,它不仅能够很好地模拟强降水过程的降水区范围、降水强度和降水中心位置,还能很好地再现低压环流系统的一些中尺度特征。

Using four cumulus convection parameterization schemes and the nonhydrostatic mesoscale numerical model MM5, the torrential rain on 25-26th July 2003 in Yunnan is simulated. The analyses on the precipitation distribution,precipitation intensity, and meso-scale low flow characteristics of the rain storm simulated indicate that the ranges of heavy rain （ 〉 25 mm ） simulated by Grell, Kain-Fritsch, and Betts-Miller scheme are all smaller than the observed;the precipitation intensity simulated by Betts-Miller scheme is much greater than the observed;and simulated results by Anthes-Kuo scheme are relatively close to the observed. The Anthes-Kuo scheme not only simulates well the process, range,intensity and central position of the heavy rain, but also reproduces well the some meso-scale characteristics of the low pressure circulation system.