{"NOAAStudyId":"15976","contactInfo":{"address":"325 Broadway, E/NE31","city":"Boulder","constraints":"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.","country":"USA","dataCenterUrl":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data","email":"paleo@noaa.gov","fax":"303-497-6513","longName":"National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce ","phone":"303-497-6280","postalCode":"80305-3328","shortName":"DOC/NOAA/NESDIS/NCEI","state":"CO","type":"CONTACT INFORMATION"},"contributionDate":"2013-12-20","dataPublisher":"NOAA","dataType":"PALEOLIMNOLOGY","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/lake","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-lake-15976.xml","doi":null,"earliestYearBP":15132,"earliestYearCE":-13182,"entryId":"noaa-lake-15976","funding":[{"fundingAgency":"US National Science Foundation","fundingGrant":null}],"investigators":"Costa, K.; Russel, J.; Konecky, B.L.; Lamb, H.F.","mostRecentYearBP":1390,"mostRecentYearCE":560,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/15976","originalSource":null,"publication":[{"abstract":"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.","author":{"name":"Costa, K., Russell, J., Konecky, B., Lamb, H."},"citation":"Costa, K., Russell, J., Konecky, B., Lamb, H. 2014. Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia. Quaternary Science Reviews, 83, 58-67. doi: http://dx.doi.org/10.1016/j.quascirev.2013.10.031","edition":null,"identifier":{"id":"http://dx.doi.org/10.1016/j.quascirev.2013.10.031","type":"doi","url":"http://dx.doi.org/http://dx.doi.org/10.1016/j.quascirev.2013.10.031"},"issue":null,"journal":"Quaternary Science Reviews","pages":"58-67","pubRank":"1","pubYear":2014,"reportNumber":null,"title":"Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia","type":"publication","volume":"83"}],"reconstruction":"N","scienceKeywords":["Tropics","hydrology","precipitation","abrupt climate change","Intertropical Convergence Zone (ITCZ)"],"site":[{"NOAASiteId":"55798","geo":{"geoType":"Feature","geometry":{"coordinates":["12","37.25"],"type":"POINT"},"properties":{"easternmostLongitude":"37.25","maxElevationMeters":"1830","minElevationMeters":"1830","northernmostLatitude":"12","southernmostLatitude":"12","westernmostLongitude":"37.25"}},"locationName":"Continent>Africa>Eastern Africa>Ethiopia","mappable":"Y","paleoData":[{"NOAADataTableId":"25965","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>hydrogen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014deterium.txt","linkText":"tana2014deterium.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"year Common Era","cvWhat":"age variable>age"},{"cvAdditionalInfo":"leaf wax interpretation","cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>bulk biological material>organic matter","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VSMOW","cvWhat":"chemical composition>isotope>isotope ratio>delta 2H"},{"cvAdditionalInfo":"leaf wax interpretation; ice volume corrected","cvDataType":"PALEOLIMNOLOGY","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>bulk biological material>organic matter","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VSMOW","cvWhat":"chemical composition>isotope>isotope ratio>delta 2H"},{"cvAdditionalInfo":"leaf wax interpretation; ice volume corrected","cvDataType":"PALEOLIMNOLOGY","cvDetail":"corrected","cvError":"two standard deviations","cvFormat":"Numeric","cvMaterial":"biological material>bulk biological material>organic matter","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VSMOW","cvWhat":"chemical composition>isotope>isotope ratio>delta 2H"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>hydrogen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014.xls","linkText":"tana2014.xls","urlDescription":"Data","variables":[]}],"dataTableName":"03TL3-deterium","dataTableNotes":null,"earliestYear":15132,"earliestYearBP":15132,"earliestYearCE":-13182,"mostRecentYear":1390,"mostRecentYearBP":1390,"mostRecentYearCE":560,"species":[],"timeUnit":"cal yr BP"},{"NOAADataTableId":"25966","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>carbon isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014d13c.txt","linkText":"tana2014d13c.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":"leaf wax interpretation","cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>bulk biological material>organic matter","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"leaf wax interpretation","cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":"two standard deviations","cvFormat":"Numeric","cvMaterial":"biological material>bulk biological material>organic matter","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"}]},{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>carbon isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014.xls","linkText":"tana2014.xls","urlDescription":"Data","variables":[]}],"dataTableName":"03TL3-d13c","dataTableNotes":null,"earliestYear":14999,"earliestYearBP":14999,"earliestYearCE":-13049,"mostRecentYear":1390,"mostRecentYearBP":1390,"mostRecentYearCE":560,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Tana Lake"}],"studyCode":null,"studyName":"Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia","studyNotes":"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.","version":"1.0","xmlId":"13757"}