【摘要】 利用地面常规资料、高空探测资料和GMS红外卫星云图资料,对2001年7月26~27日发生在山西中部的一次区域性暴雨的中尺度特征进行了诊断分析,结果表明:①此次降水是由河套西侧高空槽云系不断发展、东移,其尾部与强大的冷锋云系合并造成的,而冷锋云系中新生、发展的中β尺度暴雨云团是造成这次暴雨的直接系统;②此次暴雨过程,地面能量场表现为Ω型,且存在中尺度辐合线和中反气旋,中尺度雨团产生在辐合线北侧和中反气旋东南侧之间,辐合区与高能舌叠合,辐合区内存在较强的上升运动,是触发不稳定能量释放,产生暴雨的重要动力机制;③湿Q矢量锋生函数分布表现出明显的中尺度特征,强锋生中心位于中β尺度暴雨云团的东南侧,这是触发该暴雨云团迅速发展,产生暴雨的重要启动机制。低层暴雨中心的湿Q矢量锋生函数与降水量有滞后6 h的正相关关系。更多还原

【Abstract】 The mesoscale characteristics of the regional rain storm over the central Shanxi Province on 26,27 July 2001 are analyzed on the basis of GMS-5 infrared imagery and some conventional observation.The results show that(1) This event is caused directly by a newly developed meso-β scale cloud cluster.(2) There existed a Ω-shaped energy field on the surface,and there was a mesoscale convergence line and an anticyclone.The mesoscale rainfall cluster formed to the north of the convergence line and the southeast side of the meso-anticyclone.The convergence area was overlapped with the high energy tongue where there was strong ascending motion,which triggered energy release,was the main dynamic mechanism of the rainstorm.(3) Mesoscale characteristics can be seen in the distribution of frontogenesis function of wet Qvector.The center of strong frontogenesis function lied in the southeast of meso-β scale cloud cluster,which was the main start-up mechanism of the rainstorm.There was positive correlation between the center of frontogenesis function at the lower levels and the rainfall amount with a time lag of 6 hours.更多还原