基于NCEP资料的一次东移引发暴雨的江淮气旋结构特征分析  

Structure and mechanism analysis of a Jiang-huai cyclone with an eastern path and heavyrain based on NCEP data

作　　者：陈筱秋[1,2] 王咏青[1] 

机构地区：[1]南京信息工程大学,南京210044 [2]湖北省宜昌市气象局,宜昌443000

出　　处：《暴雨灾害》2016年第1期53-60,共8页Torrential Rain and Disasters

基　　金：中国长江电力股份有限公司科技研究项目(2414020007)

摘　　要：2015年5月1—2日由江淮气旋引发了一次江淮和江南暴雨天气过程,利用常规地面、高空观测、6 h一次的NCEP1°×1°再分析场、星下点分辨率为5 km的FY-2E水汽云图等资料,重点分析了江淮气旋的生成环境、结构特征、演变过程及东移原因,在此基础上分析了此次暴雨过程的成因。结果表明:(1)这次江淮气旋生成于500 h Pa西风槽前,西南涡沿暖切变线东移、地面冷锋进入低压倒槽的顶端;此后该气旋向东移动,但强度逐渐减弱。(2)这次江淮气旋表现为中低层浅薄系统,温度锋区弱,与经典的深厚温带气旋结构不同。江淮气旋生成时,正相对涡度区随高度向西倾斜;当高低层正相对涡度区逐渐垂直重合时,江淮气旋减弱。(3)暴雨的产生与低空急流输送的丰富水汽、500 hPa高空槽前中低层低涡、切变线、气旋等引起的强上升运动有关;暴雨区南北两支次级环流圈的存在有利于强上升运动的维持;地形抬升作用使得降水加强。(4)地面气旋中心总是沿中低层暖平流区域及其下游高低层微差涡度平流较大区域移动,移向对流层中层上升运动区。The analysis of the structure and mechanism of a Jiang-huai cyclone with an eastern path that occurred during 1-2 May 2015 was carried out using conventional observations, NCEP 1°×1°reanalysis data and water vapor images from FY-2E. Results showed that： （1） Jiang-huai cyclogenesis occurred under the conditions of a trough at 500 hPa, a low center at 850 hPa, a cold front and inverted trough at surface, which weakened with an eastern moving path. （2） The Jiang-huai cyclone was a shallow low with weak frontal zone in the lower troposphere, which is different from the deep lows of the classical extra-tropical cyclone. The positive relative vorticity tilted westward with height during the Jiang-huai cyclogenesis The positive relative vorticities at different levels were vertically overlapped while it weakened. （3） Heavy rain was caused by abundant moisture air, strong upward vertical velocity associated with the trough at 500 hPa, the low center and shear line in the low-middle troposphere, Jiang-huai cyclone and orographic uplift. （4） The Jiang-huai cyclone moved into its eastern regions with warm advection, differential vorticity advection between the upper level and low level, and upward vertical velocity in the middle troposphere.

关 键 词：江淮气旋 暴雨 浅薄系统 准地转理论 

分 类 号：P443[天文地球—大气科学及气象学]