{"NOAAStudyId":"27050","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":"2019-06-24","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-27050.xml","doi":null,"earliestYearBP":1234770,"earliestYearCE":-1232820,"entryId":"noaa-ocean-27050","funding":[{"fundingAgency":"US National Science Foundation","fundingGrant":"MGG-1060779"}],"investigators":"Robinson, R.S.","mostRecentYearBP":59790,"mostRecentYearCE":-57840,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/27050","originalSource":null,"publication":[{"abstract":"The emergence of high-amplitude, low-frequency glacial-interglacial cycles during the mid-Pleistocene climate transition (MPT; 800-1,200 ka) is associated with global cooling. In the eastern equatorial Pacific, sea surface temperatures cooled, and the upwelling-induced cold tongue expanded significantly during the MPT. Here we use sedimentary records of iron, biogenic silica, and nutrient-nitrogen consumption to evaluate biogeochemical changes hypothesized to accompany the cold tongue expansion. Our results suggest that the eastern equatorial Pacific of the MPT hosted surface waters with higher nitrate contents and biogenic silica production relative to the last 600 ka. Increased production occurred despite low iron supply. We attribute this to enhanced upwelling and nutrient enrichment of thermocline waters, both likely related to the northward migration of Southern Ocean fronts. The return of these fronts to their southward positions after the MPT may be associated with stronger drawdown of nutrients and, potentially, atmospheric CO2 in the Southern Ocean.","author":{"name":"Robinson, R.S., C.A. Jones, R.P. Kelly, P. Rafter, J. Etourneau, and P. Martinez"},"citation":"Robinson, R.S., C.A. Jones, R.P. Kelly, P. Rafter, J. Etourneau, and P. Martinez. 2019. A cool, nutrient-enriched eastern equatorial Pacific during the mid-Pleistocene transition. Geophysical Research Letters, 46. doi: 10.1029/2018GL081315","edition":null,"identifier":{"id":"10.1029/2018GL081315","type":"doi","url":"http://dx.doi.org/10.1029/2018GL081315"},"issue":null,"journal":"Geophysical Research Letters","pages":null,"pubRank":"1","pubYear":2019,"reportNumber":null,"title":"A cool, nutrient-enriched eastern equatorial Pacific during the mid-Pleistocene transition","type":"publication","volume":"46"}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"19107","geo":{"geoType":"Feature","geometry":{"coordinates":["-3.095","-90.81833"],"type":"POINT"},"properties":{"easternmostLongitude":"-90.81833","maxElevationMeters":"-3296","minElevationMeters":"-3296","northernmostLatitude":"-3.095","southernmostLatitude":"-3.095","westernmostLongitude":"-90.81833"}},"locationName":"Ocean>Pacific Ocean>South Pacific Ocean","mappable":"Y","paleoData":[{"NOAADataTableId":"39433","coreLengthMeters":41,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleocean>nitrogen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/robinson2019/robinson2019-odp846.txt","linkText":"ODP 846 d15N and Total Nitrogen Data","urlDescription":"NOAA Template File","variables":[{"cvAdditionalInfo":"ODP sample identifier","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Character","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":"ODP_SampID","cvUnit":null,"cvWhat":"sampling metadata>sample identification"},{"cvAdditionalInfo":"meters below seafloor; depth based on shipboard depth scale","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":"depth_mbsf","cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":"meters composite depth; depth based on composite depth scale from Lawrence et al.(2006)","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":"depth_mcd","cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":"age based on Lawrence et al. (2006) chronology","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":"Age_ka","cvUnit":"calendar kiloyear before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":"total nitrogen; weight percent","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"elemental analysis","cvSeasonality":null,"cvShortName":"TN%","cvUnit":"percent","cvWhat":"chemical composition>element or single-element molecule>nitrogen"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"isotope ratio mass spectrometry","cvSeasonality":null,"cvShortName":"d15N","cvUnit":"per mil AIR","cvWhat":"chemical composition>isotope>isotope ratio>delta 15N"}]}],"dataTableName":"ODP846 d15N Robinson2019","dataTableNotes":null,"earliestYear":1234770,"earliestYearBP":1234770,"earliestYearCE":-1232820,"mostRecentYear":59790,"mostRecentYearBP":59790,"mostRecentYearCE":-57840,"species":[],"timeUnit":"cal yr BP"}],"siteName":"ODP 846"}],"studyCode":null,"studyName":"Eastern Equatorial Pacific Nitrogen Data during the mid-Pleistocene Transition","studyNotes":"Measurement precision- %TN: 0.01%; d15N: 0.3 per mil.\r\n      Provided Keywords: equatorial Pacific, upwelling, nitrogen isotopes, mid-Pleistocene transition","version":"1.0","xmlId":"66714"}