作　　者： ; ; ; ; ; (金荣花）;

机构地区： 广州市气象局

出　　处： 《应用气象学报》 2013年第2期129-139,共11页

摘　　要： 2010年5月上中旬南海季风尚未爆发,广东一周内出现罕见的连续3场区域性暴雨(下称连场暴雨)。利用常规气象观测资料和NCEP分析资料,从降水时间特征和环流形势对比了连场暴雨和持续性暴雨的异同,并应用局地经向环流数值模式诊断探讨其可能形成机制。结果表明:中高纬度地区阻塞形势建立对广东5月连场暴雨和6月持续性暴雨发生均尤为关键,连场暴雨期间阻塞高压位于乌拉尔山附近,降水与中纬度短波槽南下密切相关;而持续性暴雨期间阻塞高压偏东位于亚洲大陆中部,降水主要受热带西南季风北推影响。尽管大尺度环流背景相似,但3场暴雨过程天气系统配置差异较大。数值诊断结果进一步表明:激发连续3场暴雨的主要物理因子为潜热加热、温度平流和西风动量输送。潜热加热是此次连场暴雨的正贡献和正反馈的最直接因子,而西风动量输送和温度平流对暴雨发生有一定触发作用和指示意义(超前0～1.5 d)。因此,分析和预报季风爆发前的连场暴雨过程,应注意中高纬度地区西风动量输送、冷暖平流活动和相应的天气形势演变。 Guangdong suffers from consecutive torrential rains before the onset of South China Sea Monsoon（SCSM） in May 2010, which is rarely seen in South China. Based on meteorological observations, regional au-tomatic weather station data and NCEP data, the characteristics of the consecutive torrential rains are analyzed through a comparative analysis of consecutive torrentials and persistent rains. And the possible mechanism of the consecutive torrential rains are analyed with a complete （including dynamic and thermo- dynamic mechanisms） linear-diagnostic model for the local-meridional circulation. The results show that the blocking high plays an important role in both consectutive torrential rains and persistent rains. The consectcutive torrential rains are associated with the south-eastward propagation of short wave troughs and the blocking high located over Mount Ural, while the persistent torrential rains are associated with the northward movement of the SCSM and the blocking located over central of Asian continent. There are obvious differences among the weather patterns of the three consecutive torrential rains, although the large-scale background circulations are similar. ＂5.7＂ torrential rain occurs behind up- per-level trough, lower-level shear line and cold front far from the rain belt, which is rarely observed in South China. ＂5.9＂ torrential rain is relatively typical since it occurs near the front and in the south of lower-level shear line, but upper-level short-wave trough is not clearly indentified. ＂5.14＂ torrential rain featured typical rainfall patt.ern in South China, heavy rainfall occurs in front of upper-level trough, in the south of low-level shear line and near the front. Numerical quantitative diagnosis shows that the contributors to the local meridional circulation associ- ated with the consecutive torrential rains are mainly latent heating, horizontal temperature advection and westerly momentum transport. Latent heating is the major contributor and provides positive feedb

关 键 词： 连场暴雨 持续性暴雨 阻塞高压 高空槽 冷空气

领　　域： [天文地球]