气候变化领域集成服务门户(CCPortal): Mechanisms behind early winter rainfall variability in the southwestern Cape; South Africa

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DOI	10.1007/s00382-018-4571-y
	Mechanisms behind early winter rainfall variability in the southwestern Cape; South Africa
	Mahlalela P.T.; Blamey R.C.; Reason C.J.C.
发表日期	2019
ISSN	0930-7575
起始页码	21
结束页码	39
卷号	53 期号:2020-01-02
英文摘要	The southwest region of South Africa is the only part of southern Africa that predominantly receives its total annual rainfall during the austral winter months (April–September). In 2015–2017, this part of the country experienced extreme dry conditions which led to the severe water shortages experienced in the city of Cape Town. In this study, focused is placed on understanding the contribution of the early winter period (April–May) to wet and dry years in the southwestern part of South Africa. This period is of particular interest given its key role in the recent drought, the lack of previous work on this season, and climate change projections that the winter rainy season may shorten in duration. The early winter is found to be prone to dry conditions in recent decades, such that five of the six driest April–May in recent record have occurred after the year 2000. The dry early winters in particular tend to be associated with a weaker subtropical jet, less moisture flowing into the domain and a more stable atmosphere. It is found that although there is a moderate relationship between the Southern Annular Mode and early winter rainfall, it is not as strong as that compared to the full winter period. An analysis of CMIP5 models find that the projections portray the winter rainfall region in South Africa as being exposed to an increased likelihood of early winter dry conditions into the future (2040–2060). However, it remains a challenge for these models to reasonably capture the onset of winter rainfall in South Africa. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	CMIP5; Drought; Early winter rainfall; SAM; South Africa
语种	英语
scopus关键词	Antarctic Oscillation; CMIP; drought; dry season; rainfall; wet season; winter; Cape Town; South Africa; Western Cape
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146213
作者单位	Department of Oceanography, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
推荐引用方式 GB/T 7714	Mahlalela P.T.,Blamey R.C.,Reason C.J.C.. Mechanisms behind early winter rainfall variability in the southwestern Cape; South Africa[J],2019,53(2020-01-02).
APA	Mahlalela P.T.,Blamey R.C.,&Reason C.J.C..(2019).Mechanisms behind early winter rainfall variability in the southwestern Cape; South Africa.Climate Dynamics,53(2020-01-02).
MLA	Mahlalela P.T.,et al."Mechanisms behind early winter rainfall variability in the southwestern Cape; South Africa".Climate Dynamics 53.2020-01-02(2019).