AffiliationUniv Arizona, Dept Geosci
MetadataShow full item record
PublisherAMER ASSOC ADVANCEMENT SCIENCE
CitationRainfall regimes of the Green Sahara 2017, 3 (1):e1601503 Science Advances
RightsCopyright © 2017, The Authors This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractDuring the "Green Sahara" period (11,000 to 5000 years before the present), the Sahara desert received high amounts of rainfall, supporting diverse vegetation, permanent lakes, and human populations. Our knowledge of rainfall rates and the spatiotemporal extent of wet conditions has suffered from a lack of continuous sedimentary records. We present a quantitative reconstruction of western Saharan precipitation derived from leaf wax isotopes in marine sediments. Our data indicate that the Green Sahara extended to 31 degrees N and likely ended abruptly. We find evidence for a prolonged "pause" in Green Sahara conditions 8000 years ago, coincident with a temporary abandonment of occupational sites by Neolithic humans. The rainfall rates inferred from our data are best explained by strong vegetation and dust feedbacks; without these mechanisms, climate models systematically fail to reproduce the Green Sahara. This study suggests that accurate simulations of future climate change in the Sahara and Sahel will require improvements in our ability to simulate vegetation and dust feedbacks.
NoteOpen Access Journal.
VersionFinal published version
SponsorsNational Science Foundation (NSF) [OCE-1203892]; David and Lucile Packard Foundation; NSF [OCE-0402348]; Swedish Research Council (FORMAS) as part of the Joint Programming Initiative on Climate and the Belmont Forum; Columbia University Center for Climate and Life