###
DOI:
本文二维码信息
华北一次暖区暴雨雷暴触发及传播机制研究
孙密娜1, 王秀明2, 胡玲1, 陈宏1, 韩婷婷1
(1.天津市气象台;2.中国气象局干部培训学院)
Study on thunderstorm initiation and propagation of a North-China Warm Sector Torrential Rainfall
Sun mina1, Wang xiuming2, HU Lin1, CHEN Hong1, HAN Tingting1
(1.Tianjin Meteorological Observatory;2.China Meteorological Administration Training Centre)
摘要
相似文献
本文已被:浏览 57次   下载 24
投稿时间:2017-09-24    修订日期:2018-05-30
中文摘要: 2016年7月24日午后河北中东部至天津南部出现了一次短历时暴雨过程,暴雨中心位于天津南部,模式客观预报和预报员主观预报均存在偏差。利用常规地面高空观测资料、卫星云图、多普勒雷达探测资料和同化了雷达和地面加密资料的VDRAS资料等,对此次强降水过程形成原因进行分析,结果表明: 1)本次暴雨过程发生在副高加强北上过程中,从传统流型识别的角度看不利于副高西北侧的高空槽东移影响华北东南部,这是一次发生在副高588位势什米线控制下的暖区暴雨,是非典型流型下的短历时暴雨,预报难度大;2)邢台探空较北京探空距离暴雨区更远,但对于副高西北侧西南气流影响下的暖区暴雨,位于暴雨区西南的邢台探空更具参考价值,邢台站24日11时的订正探空显示:大气层结极不稳定、低层水汽异常充沛且湿层深厚,CAPE值达3874 J?kg-1,对流抑制仅为22 J?kg-1,8g?kg-1比湿达600hPa,地面露点出现接近30℃的极端高值;3)在极不稳定和高湿环境下,边界层中尺度系统的抬升触发和组织成为关键因素,分析表明850 hPa暖式切变线附近地面两条辐合线合并,卫星云图上亦可见两条云带合并,其合并使得边界层辐合加强,因而积云在辐合区发展,暖切变线附近上午有小积云发展,随着辐合加强形成东西向排列中尺度对流系统;4)雷暴触发后,其移动和传播是预报的难点,因其决定了对流降水持续时间,本例中受辐合线和风暴阵风出流共同作用,切变线西段有新的雷暴触发,加之暖切变线南侧南北向的云街与切变线相遇,使得雷暴在向西传播的同时向南发展,即传播方向为西偏南,在环境西南气流的作用下,对流单体向东偏北方向移动,即平流方向东偏北,平流与传播方向相反,因而形成“列车效应”,另外,南北向云街表明切变线南侧逆温层之下有偏南暖湿气流补充,加之对流风暴阵风的出流再次触发雷暴使得对流风暴持续。
Abstract:Abstract: A short-time torrential rain occurred in the afternoon 24 July 2016, from the center and east of Hebei province to the south of Tianjin. The rainstorm center is located in the south of Tianjin, and the objective and forecaster's subjective forecast are all biased. The causes of the precipitation are analyzed, especially the initiation and propagation mechanism of the heavy rainstorm which are the most critical problems, by conventional surface and high observation, satellite data, radar data and VDRAS data which assimilated radar and AWS data. The results show that: 1) the torrential rain occurred on the process of subtropical high strengthen and extended northward. From the perspective of traditional, the circulation pattern doesn't favor the northwest upper trough at the edge of subtropical high moving eastward and influencing the southeast of North China. It is a warm sector torrential rain which occurred under the control of the 588 potential height line. It is a non-typical circulation pattern short-time heavy rainstorm and difficult to forecasting; 2)Although the distance from Tianjin to Xingtai is farther than from Tianjin to Beijing, Xingtai sounding located in southwest of the rainstorm zone has more reference value under the influence of southwest airflow which is on the northwest side of Subtropical High. At 11 BT, Xingtai sounding data shows that: the atmosphere is extremely unstable, and the lower layer of water vapor is deep and unusually vigorous. CAPE value is 3874 J?kg-1, CIN is 22 J?kg-1, and the height of 8g?kg-1 specific humidity extend to 600hPa. The surface dew-point temperature nearly 30℃; 3) Near the 850 hPa warm shear line, the two surface shear lines merge and mesoscale frontogenesis are the key factors of initiation. Two cloud bands are also visible on the satellite image which enhanced convergence. So cumulus clouds develop in the convergence zone, and small cumulus clouds develop in the morning near the warm shear line. As the convergence is strengthened, the mesoscale convective system is formed in the east-west direction; 4) After the thunderstorm is triggered, under the influence of the convergence line and the storm gusts, new thunderstorm initiation at the west part of the shear line, and the north-south cloud street meets the shear line on the south side of the shear line, causing the thunderstorm spreading southward and moving southward. So the propagation direction is west by south. Under the influence of southwest airflow, the convective cells move northeastwards, namely, the advection direction is east, and is opposite to the direction of propagation. Thus, the "train effect" is formed. Cloud streets show that there is a supplement of the south warm and humid air flow under the inversion layer in the south of the shear line. In addition, the convective storm gusts trigger new thunderstorms again and last the convective storm.
文章编号:201709240433     中图分类号:    文献标志码:
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目);公益性行业(气象)科研专项
引用文本:
孙密娜,王秀明,胡玲,陈宏,韩婷婷,0.[en_title][J].Meteor Mon,():-.
Sun mina,Wang xiuming,HU Lin,CHEN Hong,HAN Tingting,0.Study on thunderstorm initiation and propagation of a North-China Warm Sector Torrential Rainfall[J].Meteor Mon,():-.