雪峰山地区一次典型暴雨过程的地形敏感性模拟试验
Simulation Experiment of Topographic Sensitivity of a Typical Rainstorm Process in Xuefeng Mountain

基于中尺度数值模式，对2020年7月9日~10日邵阳地区一次典型暴雨天气过程进行数值模拟，通过改变模式初始场中雪峰山地形高度敏感性试验，分析雪峰山地形对此次过程的动力场、水汽场、热力的演变特征，对雪峰山地形影响该地区降水机制进行讨论。结果表明：模式能较好地模拟出降水的强度和雨带的位置、强降水中心的位置、雨带的形状。地形敏感试验中，地形高度的改变，可以改变降水中心的强度和降水中心的位置。雪峰山地形的高度和陡度对气流的辐合均有重要的影响；相较于存在地形的区域，地形降低之后的辐合中心较为均匀。当地形下降时，水汽辐合区较明显减弱，雪峰山地形影响了水汽辐合的强度和位置，进而影响降水中心的分布。雪峰山地形有利于气流抬升，强的垂直上升运动中心在雪峰山的迎风坡和山顶附近较为显著，尤其是雪峰山崎岖地形陡度改变后，垂直上升运动中心位于其下游。
Based on the mesoscale numerical model, a typical rainstorm weather process in Shaoyang from July 9 to 10, 2020 was numerically simulated. By changing the sensitivity test of Xuefeng Mountain terrain in the initial field of the model, the evolution characteristics of the dynamic field, water vapor field, and thermal force of Xuefeng Mountain terrain on this process were analyzed, and the precipitation mechanism of Xuefeng Mountain terrain in this region was discussed. The results indicate that the model can effectively simulate the intensity of precipitation, the location of rain bands, the position of heavy precipitation centers, and the shape of rain bands. In terrain sensitivity testing, changes in terrain height can alter the intensity and location of precipitation centers. The height and steepness of the terrain in Xuefeng Mountain have a significant impact on the convergence of airflow; Compared to areas with terrain, the convergence center after terrain reduction is more uniform. When the terrain descends, the water vapor convergence zone weakens significantly, and the terrain of Xuefeng Mountain affects the intensity and location of water vapor convergence, which in turn affects the distribution of precipitation centers. The terrain of Xuefeng Mountain is conducive to the uplift of air flow, and the strong vertical upward movement center is more significant near the windward slope and mountain top of Xuefeng Mountain, especially after the steep terrain of Xuefeng Mountain changes, the vertical upward movement center is located downstream.