{"NOAAStudyId":"19580","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":"2015-12-23","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-19580.xml","doi":null,"earliestYearBP":67500,"earliestYearCE":-65550,"entryId":"noaa-ocean-19580","funding":[{"fundingAgency":"US National Science Foundation","fundingGrant":"OCE-1204211"}],"investigators":"Hines, S.K.V.; Southon, J.R.; Adkins, J.F.","mostRecentYearBP":8500,"mostRecentYearCE":-6550,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/19580","originalSource":null,"publication":[{"abstract":"The circulation of intermediate waters plays an important role in global heat and carbon transport in the ocean and changes in their distribution are closely tied to glacial-interglacial climate change. Coupled radiocarbon and U/Th measurements on deep-sea Desmophyllum dianthus corals allow for the reconstruction of past intermediate water ventilation. We present a high-resolution time series of Antarctic Intermediate Water radiocarbon from 44 corals spanning 30 ka through the start of the Holocene, encompassing the transition into the Last Glacial Maximum (LGM) and the last deglaciation. Corals were collected south of Tasmania from water depths between 1430 and 1950 m with 80% of them between 1500 and 1700 m, giving us a continuous record from a narrow depth range. The record shows three distinct periods of circulation: the MIS 3-2 transition, the LGM/Heinrich Stadial 1 (extending from ~22 to 16 kyr BP), and the Antarctic Cold Reversal (ACR). The MIS 3-2 transition and the ACR are characterized by abrupt changes in intermediate water radiocarbon while the LGM time period generally follows the atmosphere at a constant offset, in support of the idea that the LGM ocean was at steady state for its 14C distribution. Closer inspection of the LGM time period reveals a 40 permil jump at ~19 ka from an atmospheric offset of roughly 230 permil to 190 permil, coincident with an observed 10-15 m rise in sea level and a southward shift of the Subantarctic and Polar Fronts, an abrupt change not seen in deeper records. During the ACR time period intermediate water radiocarbon is on average less offset from the atmosphere (~110 permil) and much more variable. This variability has been captured within the lifetimes of three individual corals with changes of up to 35 permil over ~40 yr, likely caused by the movement of Southern Ocean fronts. This surprising result of relatively young and variable intermediate water radiocarbon during the ACR seems to go against the canonical idea of reduced circulation and ventilation in the south during this time period. However comparisons with other records from the Southern Ocean highlight zonal asymmetries, which can explain the deviation of our Tasmanian record from those in Drake Passage and the eastern Pacific. These signals seen in Tasmanian intermediate water 14C can also be found in Greenland ice core d18O and East Asian monsoon strength. Throughout the LGM and the deglaciation, our Tasmanian intermediate water record is sensitive to times when the upper and lower cells of the meridional overturning circulation are more or less interconnected, which has important implications for the global climate system on glacial-interglacial time scales.","author":{"name":"Hines, S.K.V, J.R. Southon, and J.F. Adkins"},"citation":"Hines, S.K.V, J.R. Southon, and J.F. Adkins. 2015. A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years. Earth and Planetary Science Letters, 432, 46-58. doi: 10.1016/j.epsl.2015.09.038","edition":null,"identifier":{"id":"10.1016/j.epsl.2015.09.038","type":"doi","url":"http://dx.doi.org/10.1016/j.epsl.2015.09.038"},"issue":null,"journal":"Earth and Planetary Science Letters","pages":"46-58","pubRank":"1","pubYear":2015,"reportNumber":null,"title":"A high-resolution record of Southern Ocean intermediate water radiocarbon over the past 30,000 years","type":"publication","volume":"432"}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"56662","geo":{"geoType":"Feature","geometry":{"coordinates":["-47","-43","144","152"],"type":"POLYGON"},"properties":{"easternmostLongitude":"152","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"-43","southernmostLatitude":"-47","westernmostLongitude":"144"}},"locationName":"Ocean>Southern Ocean","mappable":"Y","paleoData":[{"NOAADataTableId":"30198","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleocean>geochemistry","earth science>paleoclimate>paleocean>age control","earth science>paleoclimate>paleocean>radiogenic isotope"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hines2015/hines2015.txt","linkText":"14C and U/Th Data","urlDescription":"Formatted Text File","variables":[{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Character","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":null,"cvWhat":"sampling metadata>sample identification"},{"cvAdditionalInfo":"Lab code used for cutting and cleaning sample","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Character","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":null,"cvWhat":"sampling metadata>notes"},{"cvAdditionalInfo":"coral collection depth","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":"U/Th age with initial 230Th correction","cvDataType":"PALEOCEANOGRAPHY","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"inductively-coupled plasma mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"chemical composition>element or compound ratio>uranium/thorium"},{"cvAdditionalInfo":"U/Th age with initial 230Th correction","cvDataType":"PALEOCEANOGRAPHY","cvDetail":"corrected","cvError":"one standard deviation","cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"inductively-coupled plasma mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"chemical composition>element or compound ratio>uranium/thorium"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"accelerator mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"radiocarbon year before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":"one standard deviation","cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"accelerator mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"radiocarbon year before present","cvWhat":"age variable>age"}]}],"dataTableName":"Tasmanian deep-sea corals Hines15","dataTableNotes":null,"earliestYear":67500,"earliestYearBP":67500,"earliestYearCE":-65550,"mostRecentYear":8500,"mostRecentYearBP":8500,"mostRecentYearCE":-6550,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Southern Ocean south of Tasmania"}],"studyCode":null,"studyName":"Southern Ocean Deep-Dea Coral Radiocarbon and U/Th Age Data over the Last 30,000 Years","studyNotes":"Seamounts range in depth from 1000 to 1947 meters. ","version":"1.0","xmlId":"17309"}