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冷涡影响下一次冰雹强对流天气中尺度特征及形成机制

尉英华陈宏张楠何群英林晓萌   


  1. (天津市气象台,天津300074)
  • 出版日期:2018-03-05 发布日期:2018-03-05
  • 作者简介:尉英华(1980—),女,高级工程师,主要从事强对流天气预报研究. E-mail:weiyinghua1980@163.com。
  • 基金资助:

    天津市自然科学基金项目(16JQNJC07500)、中国气象局预报员专项(CMAYBY2016-004)和天津市气象局气象预报预警创新团队共同资助

Analysis on Meso-scale Characteristics and Cause of a Severe Convective Hailstorm Weather Under Cold Vortex Background

WEI Yinghua, CHEN Hong, ZHANG Nan, HE Qunying, LIN Xiaomeng   

  1. (Tianjin Meteorological Observatory, Tianjin 300074, China)
  • Online:2018-03-05 Published:2018-03-05

摘要:

将NCEP/NCAR 1°×1°高空分析资料与地面加密自动站资料融合,建立高密度探空资料场,计算并分析2016年6月10日天津冰雹强对流天气过程中高分辨率时空场对流参数,结合变分多普勒天气雷达分析系统(VDRAS)的雷达热动力反演资料,研究冰雹强对流天气的发生发展机制。结果表明:此次降雹发生在蒙古冷涡环流背景下,初始回波由北京西部山区地形热力和动力强迫局地触发产生,东移进入平原区后,冷池与周边高能区形成中尺度能量锋,并诱发次级环流使雹云得以发展维持;考虑了地面温湿特征的高分辨率CAPE、LI、修正全总指数(TTm)能够反映雹云发生发展的中尺度环境特征,对雹云发生发展的局地性具有明显的指示意义,同时来自渤海的偏东水汽输送带与中尺度辐合线的交汇更有利于冰雹强对流的发生。

关键词: 冰雹, 地形, 冷池, 中尺度辐合线, 次级环流

Abstract:

Based on the fusion of NCEP 1°×1°upper air reanalysis data and automatic weather station data, high-density sounding field was established. The environmental convection parameters of this high-density space-time field were calculated and analyzed about a hailstorm convective weather on Jun 6th, 2016 in Tianjin and the development mechanism of the hailstorm was also studied combined with the retrieval data of the variational doppler radar analysis system (VDRAS). The results show that the hailstorm weather occurred under the background of Mongolia cold vortex. The local thermodynamic circulation which formed by uneven surface heating in mountain area, and the southeast airflow’s lifting, which formed by topographic forcing, they took effect together to generate convective storm in western mountain area of Beijing. During the convective cells moving eastward, the secondary circulation generated by cold pool and meso-scale energy front which formed in the surrounding high energy region, it were favorable for development and maintenance of the hailstorm. Meanwhile, the east airflow from Bohai made water vapor in the boundary layer accumulate and instability stratification develop. In addition, the indexes of CAPE, LI and TTm at high resolution considering the surface temperature and moisture could not only fill in the gap that there was no sounding stations in Tianjin, but also reflect precisely the meso-scale environmental differences in the genesis and development of hailstorm, consequently, they had obvious indicative significance for the hailstorm local characters. It was propitious to the occurance of hailstorm in the junction between surface convergence line and water vapor bands.

Key words: hailstorm terrain, cool poor, meso-scale convergence line, secondary circulation

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