2009年8月29日黄淮和西南地区不同性质暴雨特征分析  

Characteristic Analysis of Different Torrential Rain over Huanghuai Basin and Southwest China on 29 August 2009

作　　者：林建 

机构地区：[1]国家气象中心,北京100081

出　　处：《气象》2011年第3期276-284,共9页Meteorological Monthly

基　　金：公益性行业(气象)科研专项(GYHY200906010);国家气象中心预报员专项共同资助

摘　　要：利用观测资料和NCEP再分析资料,对2009年8月29日发生在黄淮和西南地区东部不同性质暴雨的垂直结构特征进行了对比分析。结果表明:两地区的暴雨发生在同一环流背景下,但却具有不同的性质,黄淮地区是锋面附近或锋后的稳定性降水,西南地区属于锋前暖区中对流性强降水特征。不同性质暴雨在涡度、散度、高低空急流配置及垂直经向环流特征上有明显的差异,湿位涡垂直分布特征也各有异同:稳定性强降水对应高层有大湿位涡舌向下伸展至对流层低层,高空冷槽东移诱发低层低涡发展,低层有高湿位涡区与强降水对应;对流性强降水对应高层湿位涡舌向下伸展至对流层中层,干冷空气侵入触发湿对称不稳定能量释放产生对流性强降水。两类不同性质暴雨其垂直结构特征具有明显的不同,可以为降水性质和短历时降水强度预报提供参考依据。In terms of the observed data and NCEP 1°×1°reanalysis data,the vertical characteristics of different feature torrential rain over Huanghuai Basin and Southwest China on 29 August 2009 are studied. Results show that the torrential rain over above two areas happened in the same circulation background, the former belongs to the stable heavy precipitation ahead of or rear of the front and the latter is of convective heavy precipitation in the warm area before the front.They have distinct differences in the vertical distribution of vorticity,divergence,jet stream at higher and lower levels,vertical meridional circulation and moist potential vorticity（MPV）.For the stable heavy precipitation,cold trough at higher levels induced the vortex at lower levels and high MPV was transferred from higher level down to the lower level of the troposphere,which resulted in the high MPV at lower levels corresponding to the heavy rain;for the convective heavy precipitation,high MPV at high levels only was transferred down to the middle level of the troposphere together with dry and cold air intruding,which triggered the moist symmetry instability energy leading to the heavy convective rain.There are significant characters of vertical structure in two different feature torrential rains,which can provide some reference for the feature and strength of short-time precipitation forecast.

关 键 词：暴雨 稳定性降水 对流性降水 湿位涡 

分 类 号：P426.65[天文地球—大气科学及气象学]