一次阵风锋过程的数值模拟与分析

Simulation and Analysis of a Gust Front Process

利用中尺度数值模式ARPS,模拟了2006年6月29日发生在南京的一次由强中尺度对流系统引发的阵风锋过程,并分析了该过程的天气形势。结果表明,在对流系统经过南京站之前,近地层出现了明显的逆温,当对流系统经过南京站时中低层湿度一直在加深;背景形势显示有中低层急流和垂直风切变。在这次数值模拟中,虽然未模拟出阵风锋的细线回波,但是较成功地模拟出雷暴单体前侧的下沉出流、冷出流与环境气流形成的辐合上升气流,以及辐合上升气流处对应阵风锋发生的位置。

Using the mesoscale numerical model ARPS, a gust front produced by a severe mesoscale convective system happened in Nanjing on 29 June 2006 was examinedand simulated.Numerical simulation result and synoptic situation were analyzed. The analysis of synoptic situation showed that there was obviously temperature inversion layer in the surface layer,and the atmospheric humidity deepened when the process of convective system move closely to the station.Jet stream and vertical wind shear were observed in synoptic situation.Though the thin line echo of gust front was not simulated,but the convergence of cold air descending and outflow from a thunderstorm and environment flow were successfully simulated.The convergence position was just the position of gust front occurring.There were obvious the internal wind stream and temperature construction in the simulation.