2010年云南“6.25”特大暴雨中尺度特征及成因的数值模拟分析

 使用1°×1°NCEP再分析资料、TBB黑体亮温资料和自动站逐时降水资料，应用MM5V3.6中尺度数值模式对2010年6月25日发生在云南曲靖马龙罕见的特大暴雨进行数值模拟，主要从动力结构和不稳定机制研究本次特大暴雨的中尺度特征及其成因.研究表明：降水发生期间中低层有较强的水汽辐合柱存在，强降水发生前中低层积累了较大的对流不稳定能量，近地层辐合线的形成诱发中低层辐合的产生，强烈的垂直上升运动促使对流不稳定能量迅速释放，触发强对流降水，高层辐散中低层辐合形成的“抽吸作用”以及利于垂直上升运动和降水的维持.地形敏感试验表明，近地层辐合线出现的位置与云南地形有很大的关系，从而影响强对流暴雨的落区.

Numerical modeling analysis on mesoscal features and forming reason of an extra torrential rain event happened on June 25th,2010 in Yunnan province

NCEP 1°×1°Reanalyzed data,TBB black bright temperature data,auto station hourly precipitation data and Mesoscale Numerical Model MM5（V3.6）were used to Simulate the Extra Torrential Rain Event Happened on June 25th,2010 in Qujing Malong of Yunnan Province.Mesoscale Features And Forming Reason of this storm rainfall event were analyzed mainly from aspects of motivational structure and instability mechanism.Results indicated that,stronger vapour convergence column existed in lower layers during the period of precipitation.Before the strong precipitation,intense convective instability energy assembled in lower layers at which the forming of sudaerial convergence lines lead to convergence.Because of intense vertical ascending motion,strong convective instability energy released quickly which contributed to intense convective precipitation.The structure of divergence in higher layers and convergence in lower layers was beneficial for the maintaining of vertical ascending motion and precipitation.Terrain sensibility experiment indicated that,the location of subaerial convergence line implicated to the terrain of Yunnan,and therefore influenced the position of convective storm rainfall.