气候变化领域集成服务门户(CCPortal): Cape storm: A dynamical study of a cut-off low and its impact on South Africa

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DOI	10.1016/j.atmosres.2020.105290
	Cape storm: A dynamical study of a cut-off low and its impact on South Africa
	Barnes M.A.; Turner K.; Ndarana T.; Landman W.A.
发表日期	2021
ISSN	0169-8095
卷号	249
英文摘要	An intense surface low pressure system and associated cut-off low (COL) that affected the south-western Cape of South Africa on 6–7 June 2017 are analysed. The storm, locally named Cape Storm, was associated with heavy rains, strong winds, runaway fires, storm surge and extremely large waves. These extreme meteorological conditions resulted in a loss of life and damage to infrastructure in various forms around the province. The societal impacts that occurred have been collected and summarized in this study. Cape Storm was tracked back to its initial development as a COL extension to a surface low pressure system to the south-west of South America. ERA-Interim reanalysis is analysed from a potential vorticity (PV) perspective to assess the factors that influenced the development of this impactful storm. The analysis found that the system was associated with a Rossby wave breaking (RWB) event and an intrusion of high-potential vorticity (PV) from the stratosphere, assisting the development of the surface low pressure system. The COL migrated across the South American continent and made its way across the South Atlantic Ocean. As it migrated towards South Africa, two more COLs associated with RWB events and stratospheric intrusions maintained and deepened the surface low pressure system, increasing its eventual impact on South Africa. The surface cyclone deepening events were both associated with high-PV in both the upper to mid-levels and lower levels of the troposphere. One of these events was associated with a deep, tightly wrapped, cyclonic intrusion of high-PV air into the troposphere and higher PV values in the lower tropospheric, resulting in rapid and intense surface cyclogenesis. © 2020 Elsevier B.V.
英文关键词	Atmospheric dynamics; Cut-off low; Explosive cyclogenesis; Rossby wave breaking; South Africa; Stratospheric intrusions; Weather extremes
语种	英语
scopus关键词	Mechanical waves; Troposphere; Vorticity; High potential; Initial development; Low pressure systems; Meteorological condition; Potential vorticity; Societal impacts; South Atlantic; Surface cyclone; Storms; atmospheric dynamics; cyclogenesis; extreme event; low pressure system; Rossby wave; storm; stratosphere; wave breaking; weather; Atlantic Ocean; Atlantic Ocean (South); South Africa; South America
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/141652
作者单位	Marine Research Unit, South African Weather Service, Cape Town, South Africa; Department of Geography, Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa; Forecasting Division, Cape Town Weather Office, South African Weather Service, Cape Town, South Africa
推荐引用方式 GB/T 7714	Barnes M.A.,Turner K.,Ndarana T.,et al. Cape storm: A dynamical study of a cut-off low and its impact on South Africa[J],2021,249.
APA	Barnes M.A.,Turner K.,Ndarana T.,&Landman W.A..(2021).Cape storm: A dynamical study of a cut-off low and its impact on South Africa.Atmospheric Research,249.
MLA	Barnes M.A.,et al."Cape storm: A dynamical study of a cut-off low and its impact on South Africa".Atmospheric Research 249(2021).