{"NOAAStudyId":"10889","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":"2011-04-22","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-10889.xml","doi":null,"earliestYearBP":24922,"earliestYearCE":-22972,"entryId":"noaa-lake-10889","funding":[{"fundingAgency":"US NOAA","fundingGrant":"NA090AR4310107"},{"fundingAgency":"Dutch Organization for Scientific  Research (NWO)","fundingGrant":null},{"fundingAgency":"FWO-Vlaanderen (Belgium) ","fundingGrant":"CHALLACEA project"}],"investigators":"Tierney, J.E.; Russell, J.M.; Sinninghe Damsté, J.S.; Huang, Y.; Verschuren, D.","mostRecentYearBP":-30,"mostRecentYearCE":1980,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/10889","originalSource":null,"publication":[{"abstract":"Both Atlantic and Indian Ocean climate dynamics exert influence \nover tropical African hydroclimate, producing complex patterns \nof convergence and precipitation. To isolate the Indian Ocean \ninfluence on African paleohydrology, we analyzed the deuterium/ \nhydrogen ratio of higher plant leaf waxes (dDwax) in a 25 000-year \nsediment record from Lake Challa (3°S, 38° E) in the easternmost \narea of the African tropics. Whereas both the seismic record of \ninferred lake level fluctuations and the Branched and Isoprenoidal \nTetraether (BIT) index proxy record changes in hydrology within \nthe Challa basin, dDwax, as a proxy for the isotopic composition \nof precipitation (dDP) is interpreted as a tracer of large-scale \natmospheric circulation that integrates the history of the moisture \ntransported to the Lake Challa area.  Specifically, based on modern- \nday isotope-rainfall relationships, we argue that Lake Challa dDwax \nreflects the intensity of East African monsoon circulation. \nThe three hydrological proxy records show generally similar trends \nfor the last 25 000 years, but there are important differences \nbetween them, primarily during the middle Holocene. We interpret \nthis deviation of dDwax from local hydrological history as a \ndecoupling of East African monsoon intensity - which heavily \ninfluences the isotopes of precipitation in East Africa today - \nfrom rainfall amount in the Challa basin. In combination, \nthe hydrological proxy data from Lake Challa singularly highlight \nzonal gradients in tropical African climate that occur over \na variety of timescales, suggesting that the Congo Air Boundary \nplays a fundamental role in controlling hydroclimate in the \nAfrican tropics. \n\n","author":null,"citation":"Tierney, J.E., J.M. Russell, J.S. Sinninghe Damsté, Y. Huang, \nand D. Verschuren. 2011. \nLate Quaternary behavior of the East African monsoon \nand the importance of the Congo Air Boundary. \nQuaternary Science Reviews, Vol. 30 (7-8), pp. 798-807. \ndoi:10.1016/j.quascirev.2011.01.017 \n","edition":null,"identifier":{"id":"10.1016/j.quascirev.2011.01.017","type":"doi","url":"http://dx.doi.org/10.1016/j.quascirev.2011.01.017"},"issue":null,"journal":"Quaternary Science Reviews","pages":null,"pubRank":"1","pubYear":2011,"reportNumber":null,"title":"Late Quaternary behavior of the East African monsoon  and the importance of the Congo Air Boundary","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":["Monsoon"],"site":[{"NOAASiteId":"47999","geo":{"geoType":"Feature","geometry":{"coordinates":["-3.3167","37.7"],"type":"POINT"},"properties":{"easternmostLongitude":"37.7","maxElevationMeters":"880","minElevationMeters":"880","northernmostLatitude":"-3.3167","southernmostLatitude":"-3.3167","westernmostLongitude":"37.7"}},"locationName":"Continent>Africa>Eastern Africa>Kenya","mappable":"Y","paleoData":[{"NOAADataTableId":"19586","coreLengthMeters":2,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleolimnology>hydrogen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/challa2011.txt","linkText":"challa2011.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":null,"cvDataType":"PALEOLIMNOLOGY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>organooxygen compound>fatty acid>n-alkanoic acid>C28 n-alkanoic acid","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VSMOW","cvWhat":"chemical composition>isotope>isotope ratio>delta 2H"},{"cvAdditionalInfo":"ice volume corrected","cvDataType":"PALEOLIMNOLOGY","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>organooxygen compound>fatty acid>n-alkanoic acid>C28 n-alkanoic acid","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/eastafrica/challa2011.xls","linkText":"challa2011.xls","urlDescription":"Data","variables":[]}],"dataTableName":"Challa001","dataTableNotes":null,"earliestYear":24922,"earliestYearBP":24922,"earliestYearCE":-22972,"mostRecentYear":-30,"mostRecentYearBP":-30,"mostRecentYearCE":1980,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Lake Challa"}],"studyCode":null,"studyName":"Lake Challa, East Africa 25KYr Leaf Wax Deuterium Data","studyNotes":"Deuterium/hydrogen ratio of higher plant leaf waxes (dDwax) \nfrom Lake Challa, Kenya, covering the last 25,000 years. \nThe chronology for the Lake Challa composite sediment sequence \nis based on a combination of 210Pb and AMS 14C dating as \npreviously described by Verschuren et al. (2009). \n\nThe composite sedimentary sequence was sampled every 4 cm \ndown to a depth of 200 cm to generate a high-resolution \n(30-50 year) record for the past two millennia, and then \nwas sampled every 16 cm (~300 years) thereafter. \nHigher sampling resolution (~100 year) was also applied \nduring the Younger Dryas interval. \n\nD/H composition of the C28 fatty acid samples (dDwax) \nwas determined via gas chromatography-isotope-ratio \nmass spectrometry. \n\n","version":"1.0","xmlId":"9452"}