九华山暴雨地形增幅作用的观测分析  

Observational Analysis of Topograpical Effect on Heavy Rainfall in Jiuhua Mountain

作　　者：丁仁海 王龙学[2] 

机构地区：[1]安徽省九华山气象台,九华山242811 [2]安徽省安庆市气象局,安庆246000

出　　处：《暴雨灾害》2009年第4期377-381,共5页Torrential Rain and Disasters

摘　　要：利用常规气象观测资料和安徽省中尺度自动气象观测网的加密资料,对2007—2008年九华山的7次暴雨天气过程,经过山区雨量和周边测站雨量的比较及山区小地形作用引起的风场变化对降水影响的综合分析,得到如下结论:九华山山区降水量明显多于周边丘陵地区,其雨量分布具有明显的山区地形雨特征。山区降水量分布受地形影响很大,迎风坡及喇叭口雨量偏多,不同高度上雨量分布存在差异。地形作用形成的风场辐合影响强降水和强对流天气的形成和发展,气流过山造成的气流加强效应有利于低空急流的加强和维持。强降水发生前,山区风场变化明显,且风场发生改变与强降水的开始和增强有一定的时间对应关系,风垂直切变的维持与强降水时段也有较好的相关性。By using the observation data of the Meso-scale Automatic Observatory Network in Anhui and the statistic data, the influence of mountainous underlying surface on the distribution and the intensity of precipitation have been analyzed after comparing the mountain area rainfall with the adjacent area rainfall on 7 heavy rainfall events in JiuHua during 2007-2008. The results show that the rainfall distribution in JiuHua has obvious characteristics of topography-induced rainfall. Mountain precipitation is higher than that in surrounding areas. The topography has a great influence on precipitation distribution, and the precipitation distribution is uneven. High rainfall is at windward slope or bell-mouthed terrain, and the difference of precipitation at different heights. The wind convergence due to the topography seems to enhance convection; the vertical wind shear caused by airflow over mountain is conducive to the strengthening and maintenance of low-level jet.. The wind field changed markedly just before the beginning of heavy precipitation, and there is a certain relationship between the change of the wind field and the beginning and intensity of the precipitation. The maintenance of vertical wind shear has a good correlation with the main rainfall period.

关 键 词：地形雨 中尺度辐合线 地形作用 自动气象站 九华山 

分 类 号：P458.121.1[天文地球—大气科学及气象学] P461.3