暴雨过程中中尺度地形作用的数值试验

Numerical Simulation of the Effects of Mesoscale Topography in a Heavy Rain Process

本文利用美国ＰＳＵ／ＮＣＡＲ中尺度模式（ＭＭ４）对１９９１年７月４—５日浙西皖南山区的大暴雨过程进行了地形作用的数值模拟对比试验。结果表明，中尺度地形对强降水区的分布和强度有重要影响，强降水中心位于山地附近；地形的动力及屏障作用对气流有明显影响；山区的水汽和热量对静力不稳定亦具有相当作用。

By use of the mesoscale model (MM4) from PSU / NCAR, a strong rainfall event during 4-5 July 1991 in the mountain area of the Zhejiang-Anhui provinces is simulated. It is found that the mesoscale mountain has significant influence on the location and intensity of the heavy rain area, the center of the heavy rain is located over the mountain area. Analysis off numerical simulation of CTR and NHT shows that the effects of the orographic dynamics and barrier on airflow plays an important role in the development of unstability. The moisture and heat in the mountain area play similar roles.