气候变化领域集成服务门户(CCPortal): South American climate during the early Eocene: Impact of a narrower Atlantic and higher atmospheric CO2

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DOI	10.1175/JCLI-D-19-0170.1
	South American climate during the early Eocene: Impact of a narrower Atlantic and higher atmospheric CO2
	Liu X.; Battisti D.S.; White R.H.; Baker P.A.
发表日期	2020
ISSN	0894-8755
起始页码	691
结束页码	706
卷号	33 期号:2
英文摘要	The Cenozoic climate of tropical South America was fundamental to the development of its biota, the most biodiverse on Earth. No previous studies have explicitly addressed how the very different atmospheric composition and Atlantic geometry during the early Eocene (approximately 55 million years ago) may have affected South American climate. At that time, the Atlantic Ocean was approximately half of its current width and the CO2 concentration of Earth's atmosphere ranged from;550 to;1500 ppm or even higher. Climate model simulations were performed to examine the effects of these major state changes on the climate of tropical South America. Reducing the width of the Atlantic by approximately half produces significant drying relative to modern climate. Drying is only partly offset by an enhancement of precipitation due to the higher CO2 of the early Eocene. The main mechanism for drier conditions is simple. Low-level air crosses the tropical Atlantic from North Africa in much less time for a narrower Atlantic (2 days) than for the modern Atlantic (;6 days); as a result, much less water is evaporated into the air and thus there is far lower moisture imported to the continent in the Eocene simulation than in the modern control. The progressive wetting (during the mid- to late Cenozoic) of the Amazon due to the widening Atlantic and the rising Andes, only partly offset by decreasing CO2 values, may have been partly responsible for the accumulating biodiversity of this region. © 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Atmospheric composition; Biodiversity; Carbon dioxide; Tropics; Atlantic Ocean; Climate model simulations; CO2 concentration; Late Cenozoic; Modern control; North Africa; South America; Tropical atlantic; Climate models; atmospheric gas; biodiversity; carbon dioxide; climate modeling; concentration (composition); Eocene; paleoclimate; precipitation (climatology); Atlantic Ocean; South America
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171483
作者单位	Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States; Division of Earth and Ocean Sciences, Duke University, Durham, NC, United States
推荐引用方式 GB/T 7714	Liu X.,Battisti D.S.,White R.H.,et al. South American climate during the early Eocene: Impact of a narrower Atlantic and higher atmospheric CO2[J],2020,33(2).
APA	Liu X.,Battisti D.S.,White R.H.,&Baker P.A..(2020).South American climate during the early Eocene: Impact of a narrower Atlantic and higher atmospheric CO2.Journal of Climate,33(2).
MLA	Liu X.,et al."South American climate during the early Eocene: Impact of a narrower Atlantic and higher atmospheric CO2".Journal of Climate 33.2(2020).