作　　者： ; ; ; ; ; ;

机构地区： 广州市气象局

出　　处： 《气象》 2011年第7期838-846,共9页

摘　　要： 利用常规观测资料和雷达资料,对广州2010年5月7日槽后大暴雨和2010年5月14日槽前大暴雨过程进行对比分析。结果表明:"5.7"大暴雨主要受500hPa高空槽后西北气流和850hPa切变线的共同作用,与典型的华南前汛期暴雨形势不同的是槽后冷空气叠加在低层暖湿气流上,对层结不稳定起到增幅作用;"5.14"大暴雨过程主要受高空槽前的西南气流、切变线和地面弱冷空气共同影响。两次大暴雨过程都是由带有超级单体的飑线引发的,前者飑线长度更长,强回波范围更大,超级单体更多,降水强度和累积降水量更大;飑线维持和发展的机制不同,前者通过补充合并两广交界处不断新生对流单体,后者则是通过吸收合并其移动前方沿近地层辐合带新生单体,得以维持和发展。 The routine observational data,the NCEP 1°×1°6 h analyzed data and Doppler radar information were used in comparing two heavy rain processes under the post-trough on 7 May and the prior-trough at 500 hPa on 14 May 2010 in Guangzhou.The results show that the 7 May torrential rain was caused by the shear line at 850 hPa and the northwesterly air flow after the trough at 500 hPa,which increased stratification unstability when it moved over the warm and wet air mass at low levels,this differs from the traditional circulation during the pre-summer flood season in South China.The＂14 May＂torreitial rain happenned under the influences of the southwesterly air flow before the trough at 500 hPa,the shear line at 850 hPa and the cold-air injection on the ground surface.The squall line affected these two processes,in which the former had longer squll line,the larger area of the strong echo in squll line,more super cells and stronger rain intensity and higher total precipitation.The mechanisms of maintaining and development of the squall line in two processes were different in that,the former relied on the supplement and merging the new cell from the border of Guangdong and Guangxi,and the latter depended on absorbing and merging the new cell ahead of it or along the convergence zone on the ground surface.

关 键 词： 大暴雨 高空槽 飑线 超级单体

领　　域： [天文地球]