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    • Historical Global observations of oceanic radiocarbon conducted prior to GEOSECS (NCEI Accession 0157456)

    Metadata Updated: December 1, 2023

    This dataset contains historical measurements of radiocarbon in oceanic dissolved inorganic carbon (map of the measurement locations). The measurements were compiled and digitized from published articles (Bien et al. 1960, 1965; Broecker et al. 1960; Fairhall and Young 1985; and Linick 1978). The data compilation contains roughly 1500 observations over the period 1955-1974. Samples were collected at the ocean surface and at various depths in the ocean interior. All of the major ocean basins are represented. The methodology involved large-volume sampling of seawater that was acidified to release CO2. The collected CO2 was analyzed for the 14C/C ratio by counting techniques at the SIO, LDEO or University of Washington laboratories. The measurements are reported as Δ14C, which includes a correction for mass dependent fractionation using measurements of δ13C in the CO2 samples. When measurements of δ13C were not available, estimates of δ13C were used to calculate Δ14C. Further details are available in the original publications. In some samples from Broecker et al. (1960), isotopic fractionation occurred while sampling. Δ14C is not affected by fractionation, due to the δ13C correction, but the reported δ13C in these cases is not representative of oceanic δ13C. We omit δ13C measurements on samples assumed to have experienced fractionation (δ13C less than -2.8 per mil or greater than +2.8 per mil), though we caution that some of the retained δ13C data from Broecker et al. (1960) may not be reliable. In some samples from Fairhall and Young (1985), a date range rather than a single date was given for the sample date. We use the midpoint of the date range for these samples. Linick (1978) updates Δ14C measurements previously reported by Bien et al. (1960; 1965), among others. We use the Δ14C data of Linick (1978) for these samples, filling in temperature and salinity data from Bien et al. (1960; 1965) that was missing in Linick (1978). Observations of dissolved inorganic carbon concentration from Fairhall and Young (1985) were converted from mM to µmol/kg by assuming constant density of 1.025 kg/l. The datafile contains 14 columns: Cruise Name, Sample Identification Number, Latitude, Longitude, Date, Depth (m), Temperature (°C), Salinity, Δ14C (/mille), Δ14C uncertainty (/mille), δ13C (/mille), δ13C uncertainty (/mille), Dissolved Inorganic Carbon concentration (µmol/kg), Source. Missing data is denoted with values of -999.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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    Dates

    Metadata Date 2023-08-30T12:31:14Z
    Metadata Created Date December 4, 2020
    Metadata Updated Date December 1, 2023
    Reference Date(s) December 11, 2016 (publication)
    Frequency Of Update asNeeded

    Metadata Source

    Harvested from NOAA/NESDIS/ncei/accessions

    Other Data Resources

    Graphic Preview

    Preview graphic

    Additional Metadata

    Resource Type Dataset
    Metadata Date 2023-08-30T12:31:14Z
    Metadata Created Date December 4, 2020
    Metadata Updated Date December 1, 2023
    Reference Date(s) December 11, 2016 (publication)
    Responsible Party (Point of Contact)
    Contact Email
    Guid gov.noaa.nodc:0157456
    Access Constraints Cite as: Graven, Heather; Kozyr, Alex; Key, Robert M. (2016). Historical Global observations of oceanic radiocarbon conducted prior to GEOSECS (NCEI Accession 0157456). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.3334/cdiac/otg.hist_c14_obs. Accessed [date]., Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose.
    Bbox East Long 28.65
    Bbox North Lat 59.5
    Bbox South Lat -71.7
    Bbox West Long 38.216667
    Coupled Resource
    Frequency Of Update asNeeded
    Graphic Preview Description Preview graphic
    Graphic Preview File https://www.ncei.noaa.gov/access/metadata/landing-page/bin/gfx?id=gov.noaa.nodc:0157456
    Graphic Preview Type PNG
    Harvest Object Id 570f5936-5972-4a70-a8ed-5bab09a3548e
    Harvest Source Id c084a438-6f6b-470d-93e0-16aeddb9f513
    Harvest Source Title NOAA/NESDIS/ncei/accessions
    Licence accessLevel: Public
    Lineage
    Metadata Language eng
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[38.216667, -71.7], [28.65, -71.7], [28.65, 59.5], [38.216667, 59.5], [38.216667, -71.7]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 1955-01-01
    Temporal Extent End 1974-12-31

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