Skip to main content
Dataset Overview | National Centers for Environmental Information (NCEI)

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

browse graphicPreview graphic
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.
  • 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].
gov.noaa.nodc:0164568
Download Data
  • HTTPS (download)
    Navigate directly to the URL for data access and direct download.
  • FTP (download)
    These data are available through the File Transfer Protocol (FTP). FTP is no longer supported by most internet browsers. You may copy and paste the FTP link to the data into an FTP client (e.g., FileZilla or WinSCP).
Distribution Formats
  • Originator data format
Ordering Instructions Contact NCEI for other distribution options and instructions.
Distributor NOAA National Centers for Environmental Information
+1-301-713-3277
NCEI.Info@noaa.gov
Dataset Point of Contact NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Time Period 1957-01-01 to 2013-12-12
Spatial Bounding Box Coordinates
West: -180
East: 180
South: -90
North: 90
Spatial Coverage Map
General Documentation
Publication Dates
  • publication: 2017-08-04
Data Presentation Form Digital table - digital representation of facts or figures systematically displayed, especially in columns
Dataset Progress Status Complete - production of the data has been completed
Historical archive - data has been stored in an offline storage facility
Data Update Frequency As needed
Purpose This dataset is available to the public for a wide variety of uses including scientific research and analysis.
Use Limitations
  • accessLevel: Public
  • Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives.
Dataset Citation
  • 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].
Cited Authors
Contributors
Resource Providers
Publishers
Theme keywords NODC DATA TYPES THESAURUS NODC OBSERVATION TYPES THESAURUS WMO_CategoryCode
  • oceanography
Global Change Master Directory (GCMD) Science Keywords Originator Keywords
  • Climatological Distributions of pH, pCO2, Total CO2, Alkalinity, and CaCO3 Saturation in the Global Surface Ocean
  • NDP-094
  • pH, pCO2, Total CO2, Alkalinity, and CaCO3 Saturation
Data Center keywords NODC COLLECTING INSTITUTION NAMES THESAURUS NODC SUBMITTING INSTITUTION NAMES THESAURUS Global Change Master Directory (GCMD) Data Center Keywords
Instrument keywords NODC INSTRUMENT TYPES THESAURUS Global Change Master Directory (GCMD) Instrument Keywords
Place keywords NODC SEA AREA NAMES THESAURUS Global Change Master Directory (GCMD) Location Keywords
Project keywords NODC PROJECT NAMES THESAURUS Global Change Master Directory (GCMD) Project Keywords Ocean Acidification Search Keywords
  • Ocean Carbon Data System (OCADS) Project
Keywords NCEI ACCESSION NUMBER
Use 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].
Access Constraints
  • 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.
Fees
  • In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: dataset
Processing Steps
  • 2017-08-04T23:03:19Z - NCEI Accession 0164568 v1.1 was published.
Output Datasets
Acquisition Information (collection)
Instrument
  • carbon dioxide (CO2) gas analyzer
  • pH sensor
  • showerhead equilibrator
  • titrator
Last Modified: 2024-03-08T13:21:40Z
For questions about the information on this page, please email: ncei.info@noaa.gov