摘要
利用GMS5水汽图像,结合红外云图、micaps资料,对发生于2001年8月13日20时至14日20时500hPa反气旋环流天气背景下的滇中暴雨中尺度云团分析。结果表明:有明显中尺度结构、在红外云图和水汽图像上都白亮的区域是产生强降水的区域;由中尺度强对流系统(MCS)发展成为中尺度对流复合体(MCC),MCC的发展和维持,是直接造成此次暴雨的中尺度系统。物理机制上,高能高湿的潜在不稳定能量的聚集、垂直风切变的存在,是利于暴雨中尺度对流云团发展的有利环境条件,暴雨落区正好集中于(θe陡立密集区;温度平流和非地转湿Q矢量与湿Q矢量散度的进一步分析表明:次级环流导致扰动的不稳定发展,使低层水汽辐合抬升,引起中尺度对流云团发展和加强,是MCC生成的主要机制。
MCC of heavy rainfall in central Yunnan Province from 20BST August 13,2001 to 20BST August 14,2001 under 500 hPa anticyclonic circulation is analyzed with GmS-5 water vapor images, infrared images and the MICAPS data. It is showed that the region which has clear meso-scale structure,and the region which has a bright appearence can produce heavy rainfall.Producing and persistence of MCC is the system which caused this rainfall process directly.The physics mechanism about this rainfall process is that the favorable environment condition of developing MCC is formed in instability of high energy and high wet,vertical wind shear.By analysis of temperature advect and non-geostrophic Q-vector we find that the ascend branch of secondary circulation made turbulence develop instably,and the forced lifting of air stream in low level brings development and intensify of mesoscale cloud cluster,it is major out-growth mechanism of MCC.
出处
《气象科学》
CSCD
北大核心
2005年第3期280-287,共8页
Journal of the Meteorological Sciences
基金
云南省"十五"科技攻关(编号:2001GN43)资助
关键词
反气旋环流
暴雨
水汽图像
中尺度云团
物理机制
Anticyclonic circulation Heavy rainfall Water vapor images MCC Physics mechanism
