noaa-lake-15976 Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia Costa, K.; Russel, J.; Konecky, B.L.; Lamb, H.F. Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia 2013-12-20 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/15976 Investigator K. Costa Investigator J. Russel Investigator B.L. Konecky Investigator H.F. Lamb earth science paleoclimate paleolimnology delta 2H,organic matter,null,per mil VSMOW,null,paleolimnology,null,null,N,leaf wax interpretation earth science paleoclimate paleolimnology delta 2H,organic matter,two standard deviations,per mil VSMOW,null,paleolimnology,corrected,null,N,leaf wax interpretation; ice volume corrected earth science paleoclimate paleolimnology depth,null,null,centimeter,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology delta 13C,organic matter,two standard deviations,per mil VPDB,null,paleolimnology,null,null,N,leaf wax interpretation earth science paleoclimate paleolimnology delta 13C,organic matter,null,per mil VPDB,null,paleolimnology,null,null,N,leaf wax interpretation earth science paleoclimate paleolimnology age,null,null,year Common Era,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology age,null,null,calendar year before present,null,paleolimnology,null,null,N,null earth science paleoclimate paleolimnology delta 2H,organic matter,null,per mil VSMOW,null,paleolimnology,corrected,null,N,leaf wax interpretation; ice volume corrected earth science paleoclimate paleolimnology carbon isotopes earth science paleoclimate paleolimnology hydrogen isotopes geoscientificInformation Intertropical Convergence Zone (ITCZ) Tropics abrupt climate change hydrology precipitation 15132 cal yr BP 1390 cal yr BP Complete 12 12 37.25 37.25 1830 1830 Continent Africa Eastern Africa Ethiopia Tana Lake>LATITUDE 12>LONGITUDE 37.25 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 Costa, K., Russell, J., Konecky, B., Lamb, H. 2014 Quaternary Science Reviews 83 58-67 http://dx.doi.org/10.1016/j.quascirev.2013.10.031

The African Humid Period of the early to mid-Holocene (12,000e5000 years ago) had dramatic ecological and societal consequences, including the expansion of vegetation and civilization into the “green Sahara.” While the humid period itself is well documented throughout northern and equatorial Africa, mechanisms behind observed regional variability in the timing and magnitude of the humid period remain disputed. This paper presents a new hydrogen isotope record from leaf waxes (dDwax) in a 15,000-year sediment core from Lake Tana, Ethiopia (12°N, 37°E) to provide insight into the timing, duration, and intensity of the African Humid Period over northeastern Africa. dDwax at Lake Tana ranges between 80‰ and 170 ‰, with an abrupt transition from D-enriched to D-depleted waxes between 13,000 e11,500 years before present (13e11.5 ka). A similarly abrupt transition from D-depleted to D-enriched waxes occurs ca 8.5e8 ka and is followed by generally D-enriched waxes throughout the late Holocene. Trends in dDwax covary with changes in Northern Hemisphere summer insolation and reflect increased precipitation at Lake Tana during the AHP; however, the transition from D-depleted to D-enriched waxes occurs earlier at Lake Tana (ca 8 ka, vs 5 ka) than in many other regional records, and the amplitude of Ddepletion during the AHP is larger at Lake Tana as well.We attribute this early enrichment to a reduction of moisture derived from westerly sources (the Congo Basin and Atlantic Ocean) which we suggest are Ddepleted relative to moisture sourced from the east (Indian Ocean) and the north (Red Sea and Mediterranean Sea). Our new record highlights the importance of both the northward migration of the tropical rain belt as well as east-west migration of the Congo Air Boundary to precipitation source and amount during the African Humid Period. STUDY NOTES: δD of the C28 n-alkanoic acid (δDwax) fromcore 03TL3 taken from Lake Tana, Ethiopia (12 N, 37.25 E, 1830m) in 2007. Keywords - Tropical paleoclimate, East Africa, Compound specific hydrogen isotopes, African Humid Period, Holocene paleoclimate, Air mass trajectories, Congo Air Boundary, Tropics, Hydrology, Intertropical Convergence Zone (ITCZ), Abrupt climate change, Precipitation, Hydrogen isotopes, Carbon isotopes.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014deterium.txt GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014.xls GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014d13c.txt USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11