noaa-lake-18355 Lake Bosumtwi, Ghana 21,000 Year Leaf Wax Hydrogen Isotope Data Shanahan, T.M.; McKay, N.P.; Hughen, K.A.; Overpeck, J.T.; Otto-Bliesner, B.L.; Heil, C.W.; King, J.W.; Scholz, C.A.; Peck, J.A. Lake Bosumtwi, Ghana 21,000 Year Leaf Wax Hydrogen Isotope Data 2015-04-08 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/18355 Investigator Shanahan, T.M. Investigator N.P. McKay Investigator K.A. Hughen Investigator J.T. Overpeck Investigator B.L. Otto-Bliesner Investigator C.W. Heil Investigator J.W. King Investigator C.A. Scholz Investigator J.A. Peck earth science paleoclimate paleolimnology delta 13C,C31 n-alkane,null,per mil PDB,null,paleolimnology,null,isotope ratio mass spectrometry,N,null earth science paleoclimate paleolimnology delta 2H,C31 n-alkane,null,per mil VSMOW,null,paleolimnology,corrected,isotope ratio mass spectrometry,N,ice-volume corrected earth science paleoclimate paleolimnology age,null,null,calendar year before present,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology carbon isotopes earth science paleoclimate paleolimnology hydrogen isotopes geoscientificInformation Monsoon 21025 cal yr BP 68 cal yr BP Complete 6.5 6.5 -1.4167 -1.4167 99 99 Continent Africa Western Africa Ghana Lake Bosumtwi>LATITUDE 6.5>LONGITUDE -1.4167 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Timothy M. Shanahan, Nicholas P. McKay, Konrad A. Hughen, Jonathan T. Overpeck, Bette Otto-Bliesner, Clifford W. Heil, John King, Christopher A. Scholz, John Peck 2015 Nature Geoscience 8 2 140-144 10.1038/ngeo2329 http://www.nature.com/ngeo/journal/v8/n2/abs/ngeo2329.html

During the African Humid Period about 14,800 to 5,500 years ago, changes in incoming solar radiation during Northern Hemisphere summers led to the large-scale expansion and subsequent collapse of the African monsoon. Hydrologic reconstructions from arid North Africa show an abrupt onset and termination of the African Humid Period. These abrupt transitions have been invoked in arguments that the African monsoon responds rapidly to gradual forcing as a result of nonlinear land surface feedbacks. Here we present a reconstruction of precipitation in humid tropical West Africa for the past 20,000 years using the hydrogen isotope composition of leaf waxes preserved in sediments from Lake Bosumtwi, Ghana. We show that over much of tropical and subtropical Africa the monsoon responded synchronously and predictably to glacial reorganizations of overturning circulation in the Atlantic Ocean, but the response to the relatively weaker radiative forcing during the African Humid Period was more spatially and temporally complex. A synthesis of hydrologic reconstructions from across Africa shows that the termination of the African Humid Period was locally abrupt, but occurred progressively later at lower latitudes. We propose that this time-transgressive termination of the African Humid Period reflects declining rainfall intensity induced directly by decreasing summer insolation as well as the gradual southward migration of the tropical rainbelt that occurred during this interval. STUDY NOTES: Hydrogen (dD) and carbon (d13C) isotope data from leaf waxes in sediments collected in Lake Bosumtwi, Ghana, covering the past 21,000 years.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/bosumtwi2015dd.txt Data File; Lake Bosumtwi 21,000 Year Leaf Wax dD and d13C Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11