摘要
基于常规观测资料、NCEP1°×1°再分析资料和广州多普勒天气雷达资料,对2010年5月14—15日广州大暴雨的环境条件、散度涡度场和中小尺度特征等进行了分析。结果表明:大暴雨过程中低层辐合高层辐散,促进气旋式涡度增加,上升运动增强,反之亦然;中层波动使得中低层辐合和中高层辐散更加深厚,进一步增强上升运动。粤西南暖湿气流北上受弱冷空气阻挡在广东省中北部地区堆积,为大暴雨提供水汽和能量。南下的弱冷空气和日变化共同形成地面强能量锋,与辐合线和低层切变线组成强有力的触发抬升机制。大暴雨期间多普勒天气雷达及时捕捉到逆风区、弱中气旋、中尺度辐合带和中层两次波动影响,分别对应两个强降水时段。
Based on the conventional observational data,NCEP 1°×1°reanalyzed data and Doppler weather radar data,the environmental conditions and meso-microscale characteristics of the torrential rainfall in Guangzhou during May 14-15 were analyzed.The results showed that strong convergences at lower levels and strong divergence at upper levels contributed to enhance of cyclonic vorticities and ascending motions,or vice versa.Middle level fluctuations also helped strengthen convergence at low-middle levels,divergence at high-middle levels and then the ascending motion.High energy airs from southwest of Guangdong were hindered by cold airs and blocked in the middle and northern parts of Guangdong to provide water vapor and energies for rainstorms.The strong surface energy front formed by weak cold air advancing south and its daily variation,combined together with surface convergence line and wind shear line at low levels provided strong trigger mechanisms jointly.Doppler weather radar could detect the adverse wind regions,weak meso-cyclone,meso-scale convergence line and twice middle-level fluctuations,which are easier to reveal two precipitation stages.
出处
《气象科学》
CSCD
北大核心
2012年第2期202-209,共8页
Journal of the Meteorological Sciences
基金
广东省科技厅社会发展气象领域科技计划项目(200907)
关键词
大暴雨
地面能量锋区
中尺度辐合系统
Rainstorms
Surface energy front
Mesoscale convergence system
