摘要
利用常规资料、NCEP 1°×1°再分析资料、卫星云图、新一代天气雷达以及区域自动站资料,分析2011年6月12日福建省龙岩市一次局地大暴雨过程中尺度对流系统特征。结果表明:此次降水过程是在高空槽东移引导弱冷空气与西南暖湿气流相互作用下产生的;暴雨落区位于层结不稳定的西南暖湿气流中(θse≥76℃),来自孟加拉湾和南海的两条水汽带为此次暴雨过程带来了充足的水汽。暴雨区主要降水时段中低层正涡度和200 hPa以下上升运动明显。通过卫星云图、雷达回波和区域自动站资料分析表明,这次局地大暴雨过程主要是由三个不同尺度的中尺度对流系统造成的,地面小尺度涡旋发展引发了第一个中-β尺度对流系统的产生,西南暖湿气流的加强、风速辐合以及有利的喇叭口地形、山脉迎风坡抬升作用为第二个中-β尺度对流系统和第三个中-γ尺度对流系统的产生和维持创造了有利的条件。
By using the conventional observation data,NCEP 1°× 1° reanalysis data,satellite pictures,CINRAD/SA data and automatic weather station data,the mesoscale characteristic of the rainstorm occurred in the west of Fujian on June 12,2011 is analyzed.The results showed that this process was caused by the interaction of the weak cold air guided by the upper though moving eastward and the southwestward warm wet airflow.The heavy rainfall area was located at the unstable southwestward warm wet airflow（θse≥ 76 ℃）,and the water vapor bands from the Bay of Bengal and South China Sea brought plenty of moisture for this storm.The main rainfall period appeared at the moment when strong ascending motion below the 200 hPa and positive vorticity at low level happened obviously.The analyses on the satellite images,radar echo and data from regional automatic stations indicate that the local heavy rainfall process was mainly caused by three different scales of mesoscale convective systems.The production of the first-β-scale convective system was triggered by the development of the near-ground small-scale vortex.The strengthening of the southwestward wet warm air,the wind speed convergence,the bell-mouthed terrain and the windward slopes uplift provided the favorable occurence and maintenance conditions for both of the second meso-βscale convective system and the third-γ-scale convective system.
出处
《暴雨灾害》
2011年第4期349-357,共9页
Torrential Rain and Disasters
基金
福建省自然科学基金项目(2010J01244)
关键词
局地大暴雨
中尺度对流系统
小涡旋
西南暖湿气流
喇叭口地形
local heavy rain
mesoscale convective systems
small vortex
southwest warm and humid air
bell-mouthed terrain
