Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China

Based on conventional observation data, satellite images, automatic observational data of precipitation and NCEP/NCAR reanalysis data (0.25°×0.25°), the mesoscale characteristics of a rainstorm caused by warm front frontogenesis were analyzed, and the cause of the rainstorm was preliminarily discuss...

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Main Authors: Li REN, Lei SUN, Guihua ZHANG, Xuemei BAI, Tianhua ZHANG
Format: Article
Language:zho
Published: Editorial Office of Torrential Rain and Disasters 2019-08-01
Series:暴雨灾害
Subjects:
Online Access:http://www.byzh.org.cn/cn/article/doi/10.3969/j.issn.1004-9045.2019.04.003
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author Li REN
Lei SUN
Guihua ZHANG
Xuemei BAI
Tianhua ZHANG
author_facet Li REN
Lei SUN
Guihua ZHANG
Xuemei BAI
Tianhua ZHANG
author_sort Li REN
collection DOAJ
description Based on conventional observation data, satellite images, automatic observational data of precipitation and NCEP/NCAR reanalysis data (0.25°×0.25°), the mesoscale characteristics of a rainstorm caused by warm front frontogenesis were analyzed, and the cause of the rainstorm was preliminarily discussed. The major conclusions were as follow. The rainstorm occurred under the condition of the strengthening and westward-stretching subtropical high and the influence of typhoon activity. Water vapor transport on the periphery of the subtropical high pressure provided abundant water vapor conditions for rainstorms. The increase of the lower southwest wind led to the warm front, strengthened the convergence and uplift of the warm front, and caused a large area of rainstorm weather. There existed the conditional symmetric instability (CSI) in the frontogenetical area. The frontogenetical effect and the release of CSI strengthened the oblique upward flow along the frontal surface and the frontal secondary circulation. The developments of slantwise convection by CSI further triggered the convective instability. The convective instability led to a large area of vertical ascending motion, and the precipitation was significantly enhanced. The sounding analysis showed that the atmosphere of warm front cloud belt was in an unstable state, which was advantageous to the convection development with short time heavy rainfall. The rainstorm was produced by the β mesoscale finger cloud. The mesoscale cloud had the characteristics of backward propagation, which was caused by the rebirth and merging of convective clouds. Heavy precipitation was mainly composed of warm cloud precipitation, high precipitation efficiency and heavy rain. The warm front was stable and less active, and the convective cell caused by warm front was repeated in the same region, and traveled along the warm front from west to east to form the train effect. The strong echo activity of the rainstorm center had a high precipitation efficiency exceeding 4 hours (maximum reflectivity of the radar echo exceeding 45 dBz), resulting in long duration of heavy rainfall and large precipitation accumulation.
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spelling doaj.art-8ec76a772a364fbe8502b43bbf5d5a322023-07-06T05:04:19ZzhoEditorial Office of Torrential Rain and Disasters暴雨灾害2097-21642019-08-0138431131910.3969/j.issn.1004-9045.2019.04.0032583Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast ChinaLi REN0Lei SUN1Guihua ZHANG2Xuemei BAI3Tianhua ZHANG4Heilongjiang Provincial Meteorological Observatory, Harbin 150030Suihua Meteorological Bureau of Heilongjiang Province, Suihua 152002Heilongjiang Provincial Meteorological Observatory, Harbin 150030Heilongjiang Provincial Meteorological Observatory, Harbin 150030Heilongjiang Provincial Meteorological Observatory, Harbin 150030Based on conventional observation data, satellite images, automatic observational data of precipitation and NCEP/NCAR reanalysis data (0.25°×0.25°), the mesoscale characteristics of a rainstorm caused by warm front frontogenesis were analyzed, and the cause of the rainstorm was preliminarily discussed. The major conclusions were as follow. The rainstorm occurred under the condition of the strengthening and westward-stretching subtropical high and the influence of typhoon activity. Water vapor transport on the periphery of the subtropical high pressure provided abundant water vapor conditions for rainstorms. The increase of the lower southwest wind led to the warm front, strengthened the convergence and uplift of the warm front, and caused a large area of rainstorm weather. There existed the conditional symmetric instability (CSI) in the frontogenetical area. The frontogenetical effect and the release of CSI strengthened the oblique upward flow along the frontal surface and the frontal secondary circulation. The developments of slantwise convection by CSI further triggered the convective instability. The convective instability led to a large area of vertical ascending motion, and the precipitation was significantly enhanced. The sounding analysis showed that the atmosphere of warm front cloud belt was in an unstable state, which was advantageous to the convection development with short time heavy rainfall. The rainstorm was produced by the β mesoscale finger cloud. The mesoscale cloud had the characteristics of backward propagation, which was caused by the rebirth and merging of convective clouds. Heavy precipitation was mainly composed of warm cloud precipitation, high precipitation efficiency and heavy rain. The warm front was stable and less active, and the convective cell caused by warm front was repeated in the same region, and traveled along the warm front from west to east to form the train effect. The strong echo activity of the rainstorm center had a high precipitation efficiency exceeding 4 hours (maximum reflectivity of the radar echo exceeding 45 dBz), resulting in long duration of heavy rainfall and large precipitation accumulation.http://www.byzh.org.cn/cn/article/doi/10.3969/j.issn.1004-9045.2019.04.003warm frontfrontogenesisconditional symmetric instability(csi)secondary circulationmesoscale convection system(mcs)typhoon
spellingShingle Li REN
Lei SUN
Guihua ZHANG
Xuemei BAI
Tianhua ZHANG
Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China
暴雨灾害
warm front
frontogenesis
conditional symmetric instability(csi)
secondary circulation
mesoscale convection system(mcs)
typhoon
title Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China
title_full Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China
title_fullStr Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China
title_full_unstemmed Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China
title_short Preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in Northeast China
title_sort preliminary analysis of mesoscale feature and causes for rainstorm caused by the warm front frontogenesis in northeast china
topic warm front
frontogenesis
conditional symmetric instability(csi)
secondary circulation
mesoscale convection system(mcs)
typhoon
url http://www.byzh.org.cn/cn/article/doi/10.3969/j.issn.1004-9045.2019.04.003
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AT guihuazhang preliminaryanalysisofmesoscalefeatureandcausesforrainstormcausedbythewarmfrontfrontogenesisinnortheastchina
AT xuemeibai preliminaryanalysisofmesoscalefeatureandcausesforrainstormcausedbythewarmfrontfrontogenesisinnortheastchina
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