气候变化领域集成服务门户(CCPortal): ‘Eastern African Paradox’ rainfall decline due to shorter not less intense Long Rains

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DOI	10.1038/s41612-019-0091-7
	‘Eastern African Paradox’ rainfall decline due to shorter not less intense Long Rains
	Wainwright C.M.; Marsham J.H.; Keane R.J.; Rowell D.P.; Finney D.L.; Black E.; Allan R.P.
发表日期	2019
ISSN	23973722
卷号	2 期号:1
英文摘要	An observed decline in the Eastern African Long Rains from the 1980s to late 2000s appears contrary to the projected increase under future climate change. This “Eastern African climate paradox” confounds use of climate projections for adaptation planning across Eastern Africa. Here we show the decline corresponds to a later onset and earlier cessation of the long rains, with a similar seasonal maximum in area-averaged daily rainfall. Previous studies have explored the role of remote teleconnections, but those mechanisms do not sufficiently explain the decline or the newly identified change in seasonality. Using a large ensemble of observations, reanalyses and atmospheric simulations, we propose a regional mechanism that explains both the observed decline and the recent partial recovery. A decrease in surface pressure over Arabia and warmer north Arabian Sea is associated with enhanced southerlies and an earlier cessation of the long rains. This is supported by a similar signal in surface pressure in many atmosphere-only models giving lower May rainfall and an earlier cessation. Anomalously warm seas south of Eastern Africa delay the northward movement of the tropical rain-band, giving a later onset. These results are key in understanding the paradox. It is now a priority to establish the balance of mechanisms that have led to these trends, which are partially captured in atmosphere-only simulations. © 2019, The Author(s).
语种	英语
scopus关键词	climate change; climate prediction; computer simulation; rainband; rainfall; teleconnection; Arabian Sea; East Africa; Indian Ocean
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/178096
作者单位	Department of Meteorology, University of Reading, Reading, United Kingdom; National Centre for Atmospheric Science (NCAS), Reading, United Kingdom; School of Earth and Environment, University of Leeds, Leeds, United Kingdom; National Centre for Atmospheric Science (NCAS), Leeds, United Kingdom; Met Office, Exeter, United Kingdom; National Centre for Earth Observation, University of Reading, Reading, United Kingdom
推荐引用方式 GB/T 7714	Wainwright C.M.,Marsham J.H.,Keane R.J.,等. ‘Eastern African Paradox’ rainfall decline due to shorter not less intense Long Rains[J],2019,2(1).
APA	Wainwright C.M..,Marsham J.H..,Keane R.J..,Rowell D.P..,Finney D.L..,...&Allan R.P..(2019).‘Eastern African Paradox’ rainfall decline due to shorter not less intense Long Rains.npj Climate and Atmospheric Science,2(1).
MLA	Wainwright C.M.,et al."‘Eastern African Paradox’ rainfall decline due to shorter not less intense Long Rains".npj Climate and Atmospheric Science 2.1(2019).