{"NOAAStudyId":"6412","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":"2003-07-01","dataPublisher":"NOAA","dataType":"PALEOCEANOGRAPHY","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/paleoceanography","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-ocean-6412.xml","doi":null,"earliestYearBP":3029653,"earliestYearCE":-3027703,"entryId":"noaa-ocean-6412","funding":[],"investigators":"Larrasoaña, J.C.; Roberts, A.P.; Rohling, E.J.; Winklhofer, M.; Wehausen, R.","mostRecentYearBP":0,"mostRecentYearCE":1950,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/6412","originalSource":null,"publication":[{"abstract":"We present a 3 million year record of aeolian dust supply into the eastern Mediterranean Sea, based on hematite contents derived from magnetic properties of sediments from Ocean Drilling Program Site 967. Our record has an average temporal resolution of ~400 years. Geochemical data validate this record of hematite content as a proxy for the supply of aeolian dust from the Sahara. We deduce that the aeolian hematite in eastern Mediterranean sediments derives from the eastern Algerian, Libyan, and western Egyptian lowlands located north of the central Saharan watershed (~21°N). In corroboration of earlier work, we relate dust flux minima to penetration of the African summer monsoon front to the north of the central Saharan watershed. This would have enhanced soil humidity and vegetation cover in the source regions, in agreement with results from \"\"green Sahara\"\" climate models. Our results indicate that this northward monsoon penetration recurred during insolation maxima throughout the last 3 million years. As would be expected, this orbital precession-scale mechanism is modulated on both short (~100-kyr) and long (~400-kyr) eccentricity time scales. We also observe a strong expression of the ~41-kyr (obliquity) cycle, which we discuss in terms of high- and low-latitude mechanisms that involve Southern Hemisphere meridional temperature contrasts and shifts in the latitudes of the tropics, respectively. We also observe a marked increase in sub-Milankovitch variability around the mid-Pleistocene transition (~0.95 Ma), which suggests a link between millennial-scale climate variability, including monsoon dynamics, and the size of northern hemisphere ice sheets.","author":null,"citation":"Larrasoaņa, J.C., A.P. Roberts, E.J. Rohling, M. Winklhofer, and R. Wehausen. 2003. Three million years of monsoon variability over the northern Sahara. Climate Dynamics, 21, 689-698.","edition":null,"identifier":null,"issue":null,"journal":"Climate Dynamics","pages":null,"pubRank":"1","pubYear":2003,"reportNumber":null,"title":"Three million years of monsoon variability over the northern Sahara","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"20707","geo":{"geoType":"Feature","geometry":{"coordinates":["34.07","32.72"],"type":"POINT"},"properties":{"easternmostLongitude":"32.72","maxElevationMeters":"-2553","minElevationMeters":"-2553","northernmostLatitude":"34.07","southernmostLatitude":"34.07","westernmostLongitude":"32.72"}},"locationName":"Ocean>Indian Ocean","mappable":"Y","paleoData":[{"NOAADataTableId":"9569","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleocean>physical properties","earth science>paleoclimate>paleocean>age control"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/larrasoana2003","linkText":"larrasoana2003","urlDescription":"Original Data and Full Metadata","variables":[]},{"NOAAKeywords":["earth science>paleoclimate>paleocean>age control","earth science>paleoclimate>paleocean>physical properties"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/paleocean/sediment_files/complete/odp967-tab.txt","linkText":"odp967-tab.txt","urlDescription":"Alternate Format Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"radiocarbon year before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":"imparted w/induction of 0.9T","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"dimensionless","cvWhat":"magnetic property>magnetic moments>remanent magnetization>isothermal remanent magnetization"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth"}]}],"dataTableName":"ODP967","dataTableNotes":"The magnetic parameter (IRM@AF, measured in A/m), is a proxy for the concentration of airborne Saharan hematite delivered into the eastern Mediterranean. This proxy reflects oscillations in dust flux that are related to wet-arid (\"green\" vs \"yellow\" Sahara) monsoon-driven cycles in the north east Sahara.","earliestYear":3029653,"earliestYearBP":3029653,"earliestYearCE":-3027703,"mostRecentYear":0,"mostRecentYearBP":0,"mostRecentYearCE":1950,"species":[],"timeUnit":"14C yr BP"}],"siteName":"ODP 967"}],"studyCode":null,"studyName":"Eastern Mediterranean (ODP967) Aeolian Hematite Data","studyNotes":null,"version":"1.0","xmlId":"2416"}