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    • Climatological Distributions of pH, pCO2, Total CO2, Alkalinity, and CaCO3 Saturation in the Global Surface Ocean (NCEI Accession 0164568)

    Metadata Updated: December 1, 2023

    Climatological mean monthly distributions of pH in the total H+ scale, total CO2 concentration (TCO2), and the degree of CaCO3 saturation for the global surface ocean waters (excluding coastal areas) are calculated using a data set for pCO2, alkalinity and nutrient concentrations in surface waters (depths less than 50 m), which is built upon the GLODAP, CARINA and LDEO database. The mutual consistency among these measured parameters is demonstrated using the inorganic carbon chemistry model with the dissociation constants for carbonic acid by Lueker et al. (2000) and for boric acid by Dickson (1990). The global ocean is divided into 24 regions, and the linear potential alkalinity (total alkalinity + nitrate) versus salinity relationships are established for each region. The mean monthly distributions of pH and carbon chemistry parameters for the reference year 2005 are computed using the climatological mean monthly pCO2 data adjusted to a reference year 2005 and the alkalinity estimated from the potential alkalinity versus salinity relationships. The climatological monthly mean values of pCO2 over the global ocean are compiled for a 4° x 5° grid for the reference year 2005, and the gridded data for each of 12 months are included in this database. This is updated version of Takahashi et al. (2009) for the reference year 2000 representing non-El Niño years using a database of about 6.5 million pCO2 data (less coastal areas of North and South America) observed in 1957-2012 (Takahashi et al., 2013). The equatorial zone (4°N-4°S) of the Pacific is excluded from the analysis because of the large interannual changes associated with the El Niño-Southern Oscillation events. The pH thus calculated ranges from 7.9 to 8.2. Lower values are located in the upwelling regions in the tropical Pacific and in the Arabian and Bering Seas; and higher values are found in the subpolar and polar waters during the spring-summer months of intense photosynthetic production. The vast areas of subtropical oceans have seasonally varying pH values ranging from 8.05 during warmer months to 8.15 during colder months. The warm tropical and subtropical waters are supersaturated by a factor of as much as 4.2 with respect to aragonite and 6.3 for calcite, whereas the cold subpolar and polar waters are less supersaturated only by 1.2 for aragonite and 2 for calcite because of the lower pH values resulting from greater TCO2 concentrations. In the western Arctic Ocean, aragonite undersaturation is observed.

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    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 2023-08-30T12:45:00Z
    Metadata Created Date December 4, 2020
    Metadata Updated Date December 1, 2023
    Reference Date(s) August 4, 2017 (publication)
    Frequency Of Update asNeeded

    Metadata Source

    Harvested from NOAA/NESDIS/ncei/accessions

    Other Data Resources

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    Additional Metadata

    Resource Type Dataset
    Metadata Date 2023-08-30T12:45:00Z
    Metadata Created Date December 4, 2020
    Metadata Updated Date December 1, 2023
    Reference Date(s) August 4, 2017 (publication)
    Responsible Party (Point of Contact)
    Contact Email
    Guid gov.noaa.nodc:0164568
    Access Constraints Cite as: Takahashi, Taro; Sutherland, Stewart C.; Chipman, David W.; Goddard, John G.; Newberger, Timothy; Sweeney, Colm (2017). Climatological Distributions of pH, pCO2, Total CO2, Alkalinity, and CaCO3 Saturation in the Global Surface Ocean (NCEI Accession 0164568). [indicate subset used]. NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.3334/cdiac/otg.ndp094. 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 180
    Bbox North Lat 90
    Bbox South Lat -90
    Bbox West Long -180
    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:0164568
    Graphic Preview Type PNG
    Harvest Object Id e6d69773-2469-4838-aa42-9fadf833c472
    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": [[[-180.0, -90.0], [180.0, -90.0], [180.0, 90.0], [-180.0, 90.0], [-180.0, -90.0]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 1957-01-01
    Temporal Extent End 2013-12-12

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