气候变化领域集成服务门户(CCPortal): Early Holocene greening of the Sahara requires Mediterranean winter rainfall

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DOI	10.1073/pnas.2024898118
	Early Holocene greening of the Sahara requires Mediterranean winter rainfall
	Cheddadi R.; Carré M.; Nourelbait M.; François L.; Rhoujjati A.; Manay R.; Ochoa D.; Schefuß E.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:23
英文摘要	The greening of the Sahara, associated with the African Humid Period (AHP) between ca. 14,500 and 5,000 y ago, is arguably the largest climate-induced environmental change in the Holocene; it is usually explained by the strengthening and northward expansion of the African monsoon in response to orbital forcing. However, the strengthened monsoon in Early to Middle Holocene climate model simulations cannot sustain vegetation in the Sahara or account for the increased humidity in the Mediterranean region. Here, we present an 18,500-y pollen and leaf-wax δD record from Lake Tislit (32° N) in Morocco, which provides quantitative reconstruction of winter and summer precipitation in northern Africa. The record from Lake Tislit shows that the northern Sahara and the Mediterranean region were wetter in the AHP because of increased winter precipitation and were not influenced by the monsoon. The increased seasonal contrast of insolation led to an intensification and southward shift of the Mediterranean winter precipitation system in addition to the intensified summer monsoon. Therefore, a winter rainfall zone must have met and possibly overlapped the monsoonal zone in the Sahara. Using a mechanistic vegetation model in Early Holocene conditions, we show that this seasonal distribution of rainfall is more efficient than the increased monsoon alone in generating a green Sahara vegetation cover, in agreement with observed vegetation. This conceptual framework should be taken into consideration in Earth system paleoclimate simulations used to explore the mechanisms of African climatic and environmental sensitivity. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	African humid period green Sahara; Holocene; Paleoclimate reconstructions; Vegetation model simulations
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238529
作者单位	Institut des Sciences de l'Évolution de Montpellier, CNRS, Institut de Recherche pour le Développement, University of Montpellier, Montpellier, 34000, France; Institut Pierre-Simon Laplace-Laboratoire d'Océanographie et du Climat, Expérimentations et approches numériques, CNRS, Institut de Recherche pour le Développement, Muséum National d'Histoire naturelle, Sorbonne Université, Pierre and Marie Curie University, Paris, 75006, France; Centro de Investigaciòn Para el Desarrollo Integral y Sostenible, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru; LGMSS, URAC45, University Chouaib Doukkali, El Jadida, 24000, Morocco; UR-SPHERES, University of Liège, Liège, 4000, Belgium; Laboratoire Géoressources, URAC42, Université Cadi Ayyad, Marrakech, 40000, Morocco; MARUM - Center for Marine Environmental Sciences, University of Bremen, Bremen, 28359, Germany
推荐引用方式 GB/T 7714	Cheddadi R.,Carré M.,Nourelbait M.,et al. Early Holocene greening of the Sahara requires Mediterranean winter rainfall[J],2021,118(23).
APA	Cheddadi R..,Carré M..,Nourelbait M..,François L..,Rhoujjati A..,...&Schefuß E..(2021).Early Holocene greening of the Sahara requires Mediterranean winter rainfall.Proceedings of the National Academy of Sciences of the United States of America,118(23).
MLA	Cheddadi R.,et al."Early Holocene greening of the Sahara requires Mediterranean winter rainfall".Proceedings of the National Academy of Sciences of the United States of America 118.23(2021).