{"NOAAStudyId":"13545","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":"2012-12-03","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-13545.xml","doi":null,"earliestYearBP":29320,"earliestYearCE":-27370,"entryId":"noaa-ocean-13545","funding":[{"fundingAgency":"US National Science Foundation","fundingGrant":"OCE 00752191"}],"investigators":"Horn, M.G.S.; Beucher, C.P.; Robinson, R.S.; Brzezinski, M.A.","mostRecentYearBP":0,"mostRecentYearCE":1950,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/13545","originalSource":null,"publication":[{"abstract":"The reinvigoration of overturning in the Southern Ocean is hypothesized to have returned CO2 from the deep ocean to the atmosphere at the end of the last ice age. Large peaks in opal accumulation have been put forward as evidence for an increase in wind driven upwelling between 10 and 15 ka. Here, we use coupled nitrogen and silicon isotope records alongside opal accumulation rates to provide quasi-quantitative estimates of Southern Ocean nutrient supply, by upwelling, and nutrient utilization across this interval. Significant changes in the consumption of N and Si across the two opal accumulation peaks indicate major changes in both upwelling and nutrient demand. We find N and Si consumption to be relatively incomplete during peak opal accumulation at the onset of the deglaciation. This indicates that nutrient supply was significantly enhanced. The second deglacial peak in opal accumulation is associated with more complete Si consumption and variable N consumption. We suggest that this peak represents strong upwelling and more complete utilization of the available silicic acid pool. Differences between the Si and N responses during opal peaks may stem from decreasing iron availability across the glacial termination. The nutrient isotope evidence for excess nutrients during the deglaciation indicates that the high export productivity was insufficient to overcome the evasion of CO2 to the atmosphere as a result of physical circulation changes. Previous work has demonstrated that the reinvigoration of overturning circulation during the deglaciation causes a transient peak in nutrient supply to the low latitudes. This is supported by our data, which indicate that relatively high macronutrient concentrations were maintained in the Southern Ocean surface waters that are incorporated into mode waters despite high demand.","author":null,"citation":"Matthew G. Horn, Charlotte P. Beucher, Rebecca S. Robinson, Mark A. Brzezinski. 2011. \r\nSouthern ocean nitrogen and silicon dynamics during the last deglaciation. \r\nEarth and Planetary Science Letters, Vol. 310, Issues 3-4, pp. 334-339.  \r\nDOI: 10.1016/j.epsl.2011.08.016","edition":null,"identifier":{"id":"10.1016/j.epsl.2011.08.016","type":"doi","url":"http://dx.doi.org/10.1016/j.epsl.2011.08.016"},"issue":null,"journal":"Earth and Planetary Science Letters","pages":null,"pubRank":"1","pubYear":2011,"reportNumber":null,"title":"Southern ocean nitrogen and silicon dynamics during the last deglaciation","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":["biogeochemical cycles"],"site":[{"NOAASiteId":"22720","geo":{"geoType":"Feature","geometry":{"coordinates":["-53.1728","5.1275"],"type":"POINT"},"properties":{"easternmostLongitude":"5.1275","maxElevationMeters":"-2848","minElevationMeters":"-2848","northernmostLatitude":"-53.1728","southernmostLatitude":"-53.1728","westernmostLongitude":"5.1275"}},"locationName":"Ocean>Southern Ocean","mappable":"Y","paleoData":[{"NOAADataTableId":"23254","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleocean>nitrogen isotopes","earth science>paleoclimate>paleocean>geochemistry"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/horn2011/horn2011.txt","linkText":"horn2011.txt","urlDescription":"Original Data and Full Metadata","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":"calendar kiloyear before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":"diatom-bound nitrogen","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>organism>diatom","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"micromole per gram","cvWhat":"chemical composition>element or single-element molecule>nitrogen"},{"cvAdditionalInfo":"diatom-bound organic matter","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>organism>diatom","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil","cvWhat":"chemical composition>isotope>isotope ratio>delta 15N"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil","cvWhat":"chemical composition>isotope>isotope ratio>delta 15N"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"micromole per gram","cvWhat":"chemical composition>element or single-element molecule>nitrogen"}]}],"dataTableName":"TN057-13PC4Horn2011","dataTableNotes":null,"earliestYear":29320,"earliestYearBP":29320,"earliestYearCE":-27370,"mostRecentYear":0,"mostRecentYearBP":0,"mostRecentYearCE":1950,"species":[],"timeUnit":"cal yr BP"}],"siteName":"TN057-13PC4"}],"studyCode":null,"studyName":"South Atlantic TN057-13PC 30 KYr Nitrogen Data","studyNotes":"Bulk sedimentary and diatom-bound N isotope values for South Atlantic core TN057-13PC spanning the last 30 ky, based on previously published ages. Bulk d15N was measured by EA-IRMS. Diatom-bound d15N was measured after physical and chemical cleaning of the diatom-opal by the persulfate-denitrifier method. ","version":"1.0","xmlId":"11586"}