{"NOAAStudyId":"25490","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":"2018-10-31","dataPublisher":"NOAA","dataType":"CLIMATE FORCING","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/climate-forcing","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-forcing-25490.xml","doi":null,"earliestYearBP":1535666,"earliestYearCE":-1533716,"entryId":"noaa-forcing-25490","funding":[{"fundingAgency":"US National Science Foundation","fundingGrant":"EAR-1349616"}],"investigators":"Dyez, K.A.; Hönisch, B.; Schmidt, G.A.","mostRecentYearBP":1384000,"mostRecentYearCE":-1382050,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/25490","originalSource":null,"publication":[{"abstract":"In the early Pleistocene, global temperature cycles predominantly varied with ~41-kyr (obliquity-scale) periodicity. Atmospheric greenhouse gas concentrations likely played a role in these climate cycles; marine sediments provide an indirect geochemical means to estimate early Pleistocene CO2. Here we present a boron isotope-based record of continuous high-resolution surface ocean pH and inferred atmospheric CO2 changes. Our results show that, within a window of time in the early Pleistocene (1.38-1.54 Ma), pCO2 varied with obliquity, confirming that, analogous to late Pleistocene conditions, the carbon cycle and climate co-varied at ~1.5 Ma. Pairing the reconstructed early Pleistocene pCO2 amplitude (92 ±13 matm) with a comparably smaller global surface temperature glacial/interglacial amplitude (3.0 ±0.5 K), yields a surface temperature change to CO2 radiative forcing ratio of S[CO2]~0.75 (±0.5) degC/Wm-2, as compared to the late Pleistocene S[CO2] value of ~1.75 (±0.6) degC/Wm-2. This direct comparison of pCO2 and temperature implicitly incorporates the large ice sheet forcing as an internal feedback and is not directly applicable to future warming. We evaluate this result with a simple climate model, and show that the presumably thinner, though extensive, northern hemisphere ice sheets would increase surface temperature sensitivity to radiative forcing. Thus, the mechanism to dampen actual temperature variability in the early Pleistocene more likely lies with Southern Ocean circulation dynamics or antiphase hemispheric forcing. We also compile this new carbon dioxide record with published Plio-Pleistocene d11B records using consistent boundary conditions and explore potential reasons for the discrepancy between Pliocene pCO2 based on different planktic foraminifera.","author":{"name":"Dyez, Kelsey A.; Hönisch, Bärbel; Schmidt, Gavin A."},"citation":"Dyez, Kelsey A.; Hönisch, Bärbel; Schmidt, Gavin A. 2018. Early Pleistocene obliquty-scale pCO2 variability at ~1.5 million years ago. Paleoceanography and Paleoclimatology. . ","edition":null,"identifier":null,"issue":null,"journal":"Paleoceanography and Paleoclimatology","pages":null,"pubRank":"1","pubYear":2018,"reportNumber":null,"title":"Early Pleistocene obliquty-scale pCO2 variability at ~1.5 million years ago","type":"publication","volume":null}],"reconstruction":"Y","scienceKeywords":null,"site":[{"NOAASiteId":"19249","geo":{"geoType":"Feature","geometry":{"coordinates":["4.77","-20.93"],"type":"POINT"},"properties":{"easternmostLongitude":"-20.93","maxElevationMeters":"-2693","minElevationMeters":"-2693","northernmostLatitude":"4.77","southernmostLatitude":"4.77","westernmostLongitude":"-20.93"}},"locationName":"Ocean>Atlantic Ocean>North Atlantic Ocean","mappable":"Y","paleoData":[{"NOAADataTableId":"37353","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>climate forcing>carbon dioxide"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/dyez2018odp668boron.txt","linkText":"ODP668 Early Pleistocene Boron Isotope and CO2 Data","urlDescription":"NOAA Template File","variables":[{"cvAdditionalInfo":null,"cvDataType":"CLIMATE FORCING|CLIMATE RECONSTRUCTIONS|PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age"},{"cvAdditionalInfo":"N-TIMS","cvDataType":"PALEOCEANOGRAPHY","cvDetail":"averaged","cvError":null,"cvFormat":"Numeric","cvMaterial":"biological material>organism>foraminifer>planktic foraminifer>Trilobatus sp.>Trilobatus sacculifer","cvMethod":"thermal ionization mass spectrometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil","cvWhat":"chemical composition>isotope>isotope ratio>delta 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property>acidity>pH"},{"cvAdditionalInfo":"based on planktic foram delta 11B","cvDataType":"CLIMATE FORCING|PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"atmospheric material>bulk atmosphere","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"parts per million","cvWhat":"chemical composition>compound>inorganic compound>carbon dioxide"},{"cvAdditionalInfo":"based on planktic foram delta 11B","cvDataType":"CLIMATE FORCING|PALEOCEANOGRAPHY","cvDetail":null,"cvError":"two standard deviations upper bound","cvFormat":"Numeric","cvMaterial":"atmospheric material>bulk atmosphere","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"parts per million","cvWhat":"chemical composition>compound>inorganic compound>carbon dioxide"},{"cvAdditionalInfo":"based on planktic foram delta 11B","cvDataType":"CLIMATE FORCING|PALEOCEANOGRAPHY","cvDetail":null,"cvError":"two standard deviations lower bound","cvFormat":"Numeric","cvMaterial":"atmospheric material>bulk atmosphere","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"parts per million","cvWhat":"chemical composition>compound>inorganic compound>carbon dioxide"}]},{"NOAAKeywords":["earth science>paleoclimate>climate forcing>carbon dioxide"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/dyez2018odp668boron.xlsx","linkText":"ODP668 Early Pleistocene Boron Isotope and CO2 Data","urlDescription":"Excel File","variables":[]}],"dataTableName":"Dyez2018ODP668boron","dataTableNotes":null,"earliestYear":1535666,"earliestYearBP":1535666,"earliestYearCE":-1533716,"mostRecentYear":1384000,"mostRecentYearBP":1384000,"mostRecentYearCE":-1382050,"species":[],"timeUnit":"cal yr BP"}],"siteName":"ODP668B"}],"studyCode":null,"studyName":"Paleo-pCO2 Database ODP668 Early Pleistocene Boron Isotope and CO2 Data","studyNotes":"Paleo-CO2 derived from boron isotope measurements on marine sediment core ODP668 the early Pleistocene 1.53-1.38 ma), plus secondary Mg/Ca-based SST reconstructions, contributed to the Paleo-pCO2 Database","version":"1.0","xmlId":"23674"}