West African Margin 25,000 Year Leaf Wax Isotope Data and Precipitation Reconstruction Tierney, J.E.; Pausata, F.; deMenocal, P.B. Tierney, J.E. Pausata, F. deMenocal, P.B. Precipitation Reconstruction earth science/paleoclimate/paleoceanography (delta 2H,C30 n-alkanoic acid,null,per mil VSMOW,null,paleoceanography,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (precipitation,delta 13C|delta 2H,one standard deviation upper bound,millimeter,annual,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (delta 2H,delta 13C|delta 2H|precipitation,one standard deviation lower bound,per mil VSMOW,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (delta 2H,delta 13C|delta 2H|precipitation,one standard deviation upper bound,per mil VSMOW,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (precipitation,delta 13C|delta 2H,null,millimeter,annual,climate reconstructions|paleolimnology,null,null,N,median value) earth science/paleoclimate/climate reconstructions|paleolimnology (age,null,null,calendar year before present,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 2H,C30 n-alkanoic acid,null,per mil VSMOW,null,paleoceanography,corrected,null,N,IV correction from scaling benthic stack (LR04) to LGM change of 1 per mil in d18O space) earth science/paleoclimate/paleoceanography (delta 13C,C30 n-alkanoic acid,null,per mil VPDB,null,paleoceanography,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (depth,null,null,centimeter,null,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleolimnology (delta 2H,delta 13C|delta 2H|precipitation,null,per mil VSMOW,null,climate reconstructions|paleolimnology,null,null,N,median value; from dD wax and d13C wax; Bayesian regression modeling) earth science/paleoclimate/climate reconstructions|paleolimnology (precipitation,delta 13C|delta 2H,one standard deviation lower bound,millimeter,annual,climate reconstructions|paleolimnology,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (OCE437-07-GC68>LATITUDE 19.363>LONGITUDE -17.282333) (OCE437-07-GC27>LATITUDE 30.879833>LONGITUDE -10.629833) (OCE437-07-GC49>LATITUDE 23.206167>LONGITUDE -17.854167) (OCE437-07-GC37>LATITUDE 26.81595>LONGITUDE -15.117717) During 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 31N 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. STUDY NOTES: Leaf wax isotope (dD and d13C) and West African precipitation reconstruction from 4 West African Margin marine sediment cores. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Tierney, J.E. Investigator : Pausata, F. Investigator : deMenocal, P.B. 2017-01-18 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/21091 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc49.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc68.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc37.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc27.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc49.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc68.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc37.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc27.txt English https://www.ncdc.noaa.gov/paleo/study/21091 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc49.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc68.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc37.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tierney2017/tierney2017gc27.txt Jessica E. Tierney, Francesco S.R. Pausata, Peter B. deMenocal2017Rainfall Regimes of the Green SaharaScience Advances31e160150310.1126/sciadv.1601503 http://advances.sciencemag.org/content/3/1/e1601503 START YEAR: 28847 cal yr BP * END YEAR: 867 cal yr BP -17.854167 19.363 -10.629833 30.879833