“5.10”岷县暴雨灾害天气过程的数值模拟和诊断分析  

Simulation and Diagnostic Analysis of '5.10' Rainstorm Disaster Weather Process in Minxian of Gansu

作　　者：杨小银[1,2] 宋广宁[1] 付培健[1] 

机构地区：[1]兰州大学大气科学学院 [2]解放军95091部队

出　　处：《高原气象》2013年第3期798-805,共8页Plateau Meteorology

基　　金：国家自然科学基金项目(41175042)资助

摘　　要：利用NCEP再分析资料和中尺度模式WRF,对2012年5月10日甘肃岷县出现的罕见雷电、短时强降水、冰雹和阵性大风等强对流天气过程进行了模拟,同时使用HYSPLIT后向轨迹模式对此次天气过程的水汽来源进行了模拟,并对模式输出的多种物理量进行了诊断分析。结果表明,WRF模式能较好地模拟此次天气过程;在此次降水发生过程中,暴雨区出现了很强的辐合上升运动,为降水的形成和发展提供了动力条件,中低层负螺旋度的短暂出现可作为降水即将发生的一个指标;来自西亚地区和孟加拉湾的水汽在甘南中层辐合,为此次暴雨提供了足够的水汽;不稳定能量的积累和释放,且能量的释放过程比积累过程快,导致暴雨的产生。A rare lightning, short-term heavy precipitation, hail, gustiness wind and other severe convec- tive weathers occur in Minxian, Gansu Province on 10 May 2012. The rainstorm process caused large casu- alties and property losses. The weather process simulated using WRF mesoscale model and NCEP reanaly- sis data. Water vapor source is simulated using backward trajectory analysis method （HYSPLIT_4 disper- sion model）. Meanwhile, the diagnostic analysis of physical quantity in the rainstorm process is carried out. The results show that WRF mesoscale model simulates well for the rainstorm process. During the precipitation process, the convergence of evere upward motion in rainstorm area provides the impetus con- dition for the formation and development of strong precipitation, and negative spiral degrees with low-rise brief appearance can be used as an indicator for the coming precipitation. Water vapor convergence from the West Asian region and the Bay of Bengal in middle level over the Gannan provides sufficient water va- por. Aggregation and release of the unstable energy, and energy release process faster than accumulation process, lead to the rainstorm generation.

关 键 词：暴雨 WRF模式 水汽通量散度 Z-螺旋度 

分 类 号：P458.121.1[天文地球—大气科学及气象学]