湖北农业科学 ›› 2021, Vol. 60 ›› Issue (17): 54-58.doi: 10.14088/j.cnki.issn0439-8114.2021.17.011

• 资源·环境 • 上一篇    下一篇

2017年青海东部两次强对流天气过程对比分析

田成娟, 张宁瑾, 梅成红, 刘雪梅, 谢天蓉   

  1. 青海省气象台,西宁 810001
  • 收稿日期:2020-09-12 出版日期:2021-09-10 发布日期:2021-09-30
  • 作者简介:田成娟(1981-),女,青海互助人,高级工程师,主要从事天气预报技术研究,(电话)13997481814(电子信箱)tcj-qxt@sohu.com。
  • 基金资助:
    中国气象局预报员专项(CMAYBY2018-080)

Comparison and analysis of two severe convective weather processes in eastern Qinghai in 2017

TIAN Cheng-juan, ZHANG Ning-jin, MEI Cheng-hong, LIU Xue-mei, XIE Tian-rong   

  1. Qinghai Meteorological Observatory,Xining 810001,China
  • Received:2020-09-12 Online:2021-09-10 Published:2021-09-30

摘要: 利用常规观测资料、NCEP1°×1°再分析资料,分析在青海省东部2017年7月23—24日和2017年7月31至8月1日发生的两次强对流天气过程(简称“7.23”和“7.31”),对比分析高低空环境场特征、动力、热力和不稳定条件。结果表明,两次强对流天气都发生在有利的大尺度环流背景下,主要成因是地面冷空气从河西走廊扩散南下,与西南暖湿气流在青海东部交汇;触发机制是500 hPa干舌、地面干线,地面辐合线,地面冷锋;两次过程都是高层辐散,低层辐合的典型配置,“7.31”以倾斜上升运动为主,“7.23”低层水汽辐合强于“7.31”;两次过程都有两条水汽带,一条为副热带高压西侧的东南气流输送水汽带,另一条为高空槽前冷空气携带水汽带;500 hPa附近有350 K假相当位温(θse)高值中心,38°N附近有倾斜的θse等值线密集带,这种锋生带更有利于短时强降水发展和维持。

关键词: 强对流天气, 温湿特征, 层结不稳定, 对比分析, 青海东部

Abstract: Based on conventional observation data, NCEP 1° ×1° reanalysis data, two severe convective weather processes occurred in eastern Qinghai province from July 23 to 24, 2017 (referred to as “7.23”) and from July 31 to August 1, 2017 (referred to as “7.31”)were analyzed, and the characteristics of upper and lower environment field, dynamic, water vapor, thermal and convective instability conditions were compared. The results showed that the two severe convective weather processe occurred under the favorable background of large-scale circulation, and the main cause was that the surface cold air diffused southward from the Hexi Corridor and interacted with the southwest warm and humid air in the eastern part of Qinghai. The processes were triggered by dry tongue at 500 hPa, surface dew-point line, convergence line and surface cold front. Both processes were typical configurations of upper level divergence and lower level convergence, “7.31” was dominated by oblique ascending movement, and the water vapor convergence in the lower layer of “7.23” was stronger than that of “7.31”. There were two water vapor belts in the two processes, one was the water vapor belt carried by the southeast airflow on the west side of the subtropical high, and the other was the water vapor belt carried by the cold air in front of the upper trough. There was a high-value center of 350 K θse near 500 hPa, and a tilted intensive belt of θse near 38°N. This frontogenesis zone was more conducive to the development and maintenance of short-term heavy precipitation.

Key words: severe convective weather, temperature-humidity characteristic, unstable stratification, comparative analysis, Eastern Qinghai

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