气候变化领域集成服务门户(CCPortal): The Cape Town “Day Zero” drought and Hadley cell expansion

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DOI	10.1038/s41612-019-0084-6
	The Cape Town “Day Zero” drought and Hadley cell expansion
	Burls N.J.; Blamey R.C.; Cash B.A.; Swenson E.T.; Fahad A.; Bopape M.-J.M.; Straus D.M.; Reason C.J.C.
发表日期	2019
ISSN	23973722
卷号	2 期号:1
英文摘要	In early 2018, Cape Town (population ~3.7 million) was at risk of being one of the first major metropolitan areas in the world to run out of water. This was due to a severe multi-year drought that led to the levels of supply dams falling to an unprecedented low. Here we analyze rainfall data from the city catchment areas, including rare centennial records from the surrounding region, to assess the severity of the 2015–2017 drought. We find that there has been a long-term decline in the number of winter rainfall days, but this trend has been generally masked by fluctuations in rainfall intensity. The recent drought is unprecedented in the centennial record and represents a combination of the long-term decline in rainfall days and a more recent decline in rainfall intensity. Cold fronts during the winter months are responsible for most of the rainfall reaching Cape Town and our analysis shows no robust regional trend in the number of fronts over the last 40 years. Rather, the observed multidecadal decline in rainfall days, which threatens to increase the occurrence of severe drought, appears to be linked to a decrease in the duration of rainfall events associated with cold fronts. This change in rainfall characteristics associated with fronts appears to be linked to Hadley Cell expansion seen across the Southern Hemisphere and an increasing trend in post-frontal high-pressure conditions that suppress orographically enhanced rainfall. © 2019, The Author(s).
语种	英语
scopus关键词	decadal variation; drought; Hadley cell; high pressure system; precipitation intensity; temporal record; Cape Town; South Africa; Western Cape
来源期刊	npj Climate and Atmospheric Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178103
作者单位	Department of Atmospheric, Oceanic and Earth Sciences & the Center for Ocean-Land-Atmosphere Studies, George Mason University, Fairfax, VA 22030, United States; Department of Oceanography, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa; South African Weather Service, Private Bag X097, Pretoria, 0001, South Africa
推荐引用方式 GB/T 7714	Burls N.J.,Blamey R.C.,Cash B.A.,等. The Cape Town “Day Zero” drought and Hadley cell expansion[J],2019,2(1).
APA	Burls N.J..,Blamey R.C..,Cash B.A..,Swenson E.T..,Fahad A..,...&Reason C.J.C..(2019).The Cape Town “Day Zero” drought and Hadley cell expansion.npj Climate and Atmospheric Science,2(1).
MLA	Burls N.J.,et al."The Cape Town “Day Zero” drought and Hadley cell expansion".npj Climate and Atmospheric Science 2.1(2019).