摘要
利用NCEP的1°×1°再分析资料、FY-2E逐小时TBB资料以及常规气象观测资料,对湘中地区2010年5月12-13日大暴雨过程的环流形势、物理量场以及中尺度系统进行综合分析,试图从多角度揭示这次大暴雨天气的成因。结果表明:高空南支槽,中低层切变以及地面冷空气是这次大暴雨天气过程的主要影响系统;低空急流作为暖湿气流的载体,为暴雨的产生提供了充足的能量条件和水汽条件;冷空气侵入高能不稳定的暖湿气团,是触发暴雨不稳定能量释放的热力机制;z-螺旋度的空间分布能反映暴雨发生时大气的动力特征,中低层强辐合,高层强辐散与低层正涡度的空间结构,有利于高低层形成"抽吸作用",从而使上升运动得到发展和加强,为暴雨的产生提供有利的动力条件;高分辨率的云顶亮温TBB资料对降水的强度及落区有很好的指示意义。
Using NCEP1°×1°re-analysis data,FY-2E-by-hour TBB data and conventional meteorological observation data,the circulation,physical quantity field and mesoscale system of heavy rainfall in mid-Hunan Province during 12th-13th May 2010 are analyzed.By the analysis we try to reveal the causes of heavy rainfall from the multiple perspectives.The results showed that the main influencing system of heavy rainfall is high-altitude southern branch trough,the low level shear and the surface cold air;The warm vapor with high moisture carried by the lower stream jet provides sufficient energy and water vapor;The cold air invade the extreme unstable warm air mass with high moisture is the thermodynamic mechanism to release the high unstable energy of heavy rainfall.The spatial distribution of z-helicity depict the dynamic characteristic of the atmosphere when the heavy rainfall occurs.The structure of the lower level strong convergence,the upper strong divergence and the lower positive vorticity is propitious to the formation of high level and low level 'pump effect',so that the upward air motion gets enhanced and developed,all these conditions provide a advantaged dynamic condition for the heavy rainfall.The high resolution TBB data is a good meaning for the precipitation intensity and location.
出处
《成都信息工程学院学报》
2011年第2期215-222,共8页
Journal of Chengdu University of Information Technology
关键词
气象学
诊断分析
水汽条件
假相当位温sθe
z-螺旋度
MCS
meteorology
diagnostic analysis
water vapor condition
pseudo-equivalent temperature(θse)
z-helicity
mesoscale convective system(MCS)
