首先对2005年6月10日(简称“05—6”)发生在辽宁省的一次龙卷风过程进行了诊断分析,然后,利用美国新一代中尺度气候研究与预报模型(WRF)进行了数值模拟试验。诊断分析结果显示:低空强辐合与高空强辐散的配置在6月10日14时前后达到鼎盛时期,为强对流提供了充分的条件。上干冷下暖湿的大气层结不稳定结构和近地面的水汽通量辐合,为龙卷风的发生提供了持续的能量和充足的水汽条件。数值模拟结果表明:WRF模式能够比较成功地再现此次龙卷风过程,其结果与诊断分析相符。模拟的辽西地区的不稳定能量和气柱上升运动的配置关系从10日上午开始,在当日14—15时达到一个峰值,导致了16时龙卷风的发生。另外,不论是在诊断分析还是数值模拟的结果中所体现出的强烈的对流运动和较小的影响范围,都十分符合龙卷风这种小尺度强对流系统的特征。
In this paper, a diagnostic analysis and numerical simulation test using the new generation of mesoscale model of America (Weather Research Forecast Model,WRF) were conducted to research the course of the tornado occurring in Liaoning Province on June 10,2005. The results of diagnosis show that the cooperation of strong convergence in low level and divergence in upper air reached the great prosperous period and offered sufficient condition for strong convection. At the same time, the unstable stratification attributed to the dry, cold top and warm, wet underpart and convergence of vapor flux in low level provided persistent energy and ample vapor condition. The numerical simulation results show that WRF could successfully imaged this tornado course and the resultes accorded with the diagnosis. In the simulative results, the unstable energy and ascending air in west of Liaoning Province assorted from the morning on June 10th and reached the peak value at 14:00 - 15:00, then led the tornado at 16:00. Besides, the strong convection and small incidence existed in either the results of diagnosis or simulation accord with the character of tornado, a microscale system with strong convection.