台风“凤凰”登陆过程的高分辨率数值模拟及其降水的诊断分析

The High-Resolution Numerical Simulation and Diagnostic Analysis of the Landfall Process of Typhoon Fungwong

本文利用中尺度非静力数值模式WRF对2008年第8号台风"凤凰"的登陆过程开展了高分辨率数值模拟,模拟采用3重嵌套,最高分辨率3km,共积分120小时(5天)。利用收集到的常规和非常规观测资料与模式模拟结果进行了细致的对比验证分析。结果指出,模式较好地模拟再现了"凤凰"台风的发展演变以及登陆过程,模拟的台风路径与观测路径较为一致,同时模式也较好地把握住了整个模拟时段当中,"凤凰"台风的强度演变过程以及主要的雷达回波特征,模拟取得了初步成功。进一步,利用高分辨率的模拟资料对此次台风登陆过程开展了散度垂直通量|Q|的诊断分析,结果表明,在整个研究时段内,|Q|的异常值区始终覆盖在地面雨区之上,二者的空间分布和时间演变趋势比较相似,并且在雨区内|Q|表现为强信号,而在非雨区|Q|表现为弱信号。这表明散度垂直通量能够描述暴雨过程中低层大气辐合和高层大气辐散的垂直动力结构,对强降水落区有较好的指示作用。

By using non-hydrostatic WRF（Weather Research Forecast） model,the landfall process of typhoon Fungwong are simulated in high resolution.The simulation is triple nesting with the highest resolution of 3 km and integrated 120 hours（5 days）.The authors also carried out careful comparison between the simulation results and the real situation（the conventional and unconventional observational data）.The results show that the WRF model successfully simulated the development and landfall process of typhoon Fungwong,the simulated path is quite consistent with the observed one.At the same time the model also successfully showed the evolution process and the feature of main radar echo in the whole simulation period,the simulation is successful.Further more,with the high-resolution simulated data the authors carried out diagnosis analysis of ｜Q｜ to the landing process of typhoon.It shows that the abnormal value area of ｜Q｜ always cover the rainfall area in the whole period,they have the similar spatial distributions and time evolution trends.And ｜Q｜ shows strong signals in the rainfall area and shows weak ones in the non-rainfall area.To sum up,｜Q｜ has good indicative meanings to forecast of the strong precipitation.