Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner Mongolia

Based on the conventional observation data, automatic weather station data, Doppler radar data and NCEP(0.25°×0.25°) reanalysis data, a strong convective weather event occurred in the southeastern Inner Mongolia on 24 September 2016 caused by the disaster squall line was analyzed. The main conclusio...

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Main Authors: Guilian ZHANG, Yanli ZHAO, Xiaolu HUANG, Yanwen QI, Xin CHANG, Hui LI
Format: Article
Language:zho
Published: Editorial Office of Torrential Rain and Disasters 2019-02-01
Series:暴雨灾害
Subjects:
Online Access:http://www.byzh.org.cn/cn/article/doi/10.3969/j.issn.1004-9045.2019.01.005
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author Guilian ZHANG
Yanli ZHAO
Xiaolu HUANG
Yanwen QI
Xin CHANG
Hui LI
author_facet Guilian ZHANG
Yanli ZHAO
Xiaolu HUANG
Yanwen QI
Xin CHANG
Hui LI
author_sort Guilian ZHANG
collection DOAJ
description Based on the conventional observation data, automatic weather station data, Doppler radar data and NCEP(0.25°×0.25°) reanalysis data, a strong convective weather event occurred in the southeastern Inner Mongolia on 24 September 2016 caused by the disaster squall line was analyzed. The main conclusions are as follows. In the high and middle levels, cold and dry air masses spread to the southeast with the convergence of the low southwestern jet drastically strengthened, which provides this strong squall line process a very good large-scale circulation background. The CAPE has a significant increase before the strong convective weather occurred. The middle and low level distribution of θse presents like inverted funnel, and decreases with the increase of the height. This kind of dry and wet structure is favorable for the occurrence of strong convective weather such as thunderstorms and hails. The direct trigger and maintenance mechanism of this strong convective weather are due to the longtime maintaining, coupling and increasing between ground scale dew point front(dry line) and mesoscale convergence line. The thunderstorm high pressure stayed after the squall line indicating that there is a surface strong wind. The characteristic of radar echo appears like bow echo. The reflectivity profile of the bow echo front shows that there is a boundary weak echo region(BWER) in the lower layer. In the high-level, it has obvious echo drape. Strong echo zone achieve 50-55 dBz extends to 7.5 km, indicating that a strong upward flow is in the convective storm which is conducive to the formation of short-term heavy rainfall and the large hail. The arcuate velocity profile of the bow echo represents a strong sinking airflow and the middle ground radial convergence (MARC) of the ground wind warning index.
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spelling doaj.art-6e65a0ac24454bd292d0a068176dc41a2023-07-06T05:04:28ZzhoEditorial Office of Torrential Rain and Disasters暴雨灾害2097-21642019-02-01381414710.3969/j.issn.1004-9045.2019.01.0052547Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner MongoliaGuilian ZHANG0Yanli ZHAO1Xiaolu HUANG2Yanwen QI3Xin CHANG4Hui LI5Inner Mongolia Autonomous Region Meteorological Observatory, Huhhot 010051Inner Mongolia Autonomous Region Climate Center, Huhhot 010051Inner Mongolia Autonomous Region Meteorological Observatory, Huhhot 010051TongLiao Meteorological Bureau of Inner Mongolia Autonomous Region, TongLiao 028000ChiFeng Meteorological Bureau of Inner Mongolia Autonomous Region, ChiFeng 024000Inner Mongolia Autonomous Region Meteorological Observatory, Huhhot 010051Based on the conventional observation data, automatic weather station data, Doppler radar data and NCEP(0.25°×0.25°) reanalysis data, a strong convective weather event occurred in the southeastern Inner Mongolia on 24 September 2016 caused by the disaster squall line was analyzed. The main conclusions are as follows. In the high and middle levels, cold and dry air masses spread to the southeast with the convergence of the low southwestern jet drastically strengthened, which provides this strong squall line process a very good large-scale circulation background. The CAPE has a significant increase before the strong convective weather occurred. The middle and low level distribution of θse presents like inverted funnel, and decreases with the increase of the height. This kind of dry and wet structure is favorable for the occurrence of strong convective weather such as thunderstorms and hails. The direct trigger and maintenance mechanism of this strong convective weather are due to the longtime maintaining, coupling and increasing between ground scale dew point front(dry line) and mesoscale convergence line. The thunderstorm high pressure stayed after the squall line indicating that there is a surface strong wind. The characteristic of radar echo appears like bow echo. The reflectivity profile of the bow echo front shows that there is a boundary weak echo region(BWER) in the lower layer. In the high-level, it has obvious echo drape. Strong echo zone achieve 50-55 dBz extends to 7.5 km, indicating that a strong upward flow is in the convective storm which is conducive to the formation of short-term heavy rainfall and the large hail. The arcuate velocity profile of the bow echo represents a strong sinking airflow and the middle ground radial convergence (MARC) of the ground wind warning index.http://www.byzh.org.cn/cn/article/doi/10.3969/j.issn.1004-9045.2019.01.005squall linebow echodry linemiddle-scale convergence lineboundary weak echo regionmid-altitude radial convergence
spellingShingle Guilian ZHANG
Yanli ZHAO
Xiaolu HUANG
Yanwen QI
Xin CHANG
Hui LI
Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner Mongolia
暴雨灾害
squall line
bow echo
dry line
middle-scale convergence line
boundary weak echo region
mid-altitude radial convergence
title Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner Mongolia
title_full Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner Mongolia
title_fullStr Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner Mongolia
title_full_unstemmed Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner Mongolia
title_short Causality analysis of a disaster-causing squall line event on 24 September in southeastern Inner Mongolia
title_sort causality analysis of a disaster causing squall line event on 24 september in southeastern inner mongolia
topic squall line
bow echo
dry line
middle-scale convergence line
boundary weak echo region
mid-altitude radial convergence
url http://www.byzh.org.cn/cn/article/doi/10.3969/j.issn.1004-9045.2019.01.005
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