Dissolved inorganic carbon (DIC), total alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations during the R/V Aurora Australis cruise AU0806, CLIVAR_SR03_2008 (EXPOCODE 09AR20080322) in the Indian Ocean from 2008-03-22 to 2008-04-17 (NCEI Accession 0109900)

Description

This dataset includes discrete profile measurements of dissolved inorganic carbon (DIC), total alkalinity, temperature, salinity, dissolved oxygen, nutrients, chlorofluorocarbons (CFC-11, CFC-12, CFC113) and dissolved organic carbon (DOC) during the R/V Aurora Australis cruise AU0806, CLIVAR_SR03_2008 (EXPOCODE 09AR20080322) in the Indian Ocean from 2008-03-22 to 2008-04-17. These data were collected by Bronte Tilbrook and Stephen R. Rintoul of Commonwealth Scientific and Industrial Research Organization (CSIRO) as part of the CLIVAR_SR03_2008 dataset. The International CLIVAR Global Ocean Carbon and Repeat Hydrography Program carries out a systematic and global re-occupation of select WOCE/JGOFS hydrographic sections to quantify changes in storage and transport of heat, fresh water, carbon dioxide (CO2), and related parameters.

Resources

Name Format Description Link
0 Institution web page http://cdiac.ornl.gov
0 Institution web page http://www.utas.edu.au
0 Navigate directly to the URL for data access and direct download. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/data/0109900/
0 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). ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0058/0109900/
0 Institution web page http://cdiac.ornl.gov
0 Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Institution web page http://www.utas.edu.au
0 Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Institution web page http://www.utas.edu.au
0 Institution web page http://www.rsmas.miami.edu
0 Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 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). ftp://ftp-oceans.ncei.noaa.gov/pub/data.nodc/ncei/ocads/data/0109900/
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
21 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0109900.html
0 Navigate directly to the URL for a descriptive web page with download links. https://doi.org/10.3334/cdiac/otg.clivar_sr03_2008
0 Navigate directly to the URL for a descriptive web page. https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system
0 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/archive/accession/oas/109900
0 Navigate directly to the URL for data access and direct download. https://www.ncei.noaa.gov/archive/accession/download/109900
0 Global Change Master Directory (GCMD). 2023. GCMD Keywords, Version 16. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 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). ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0058/0109900/
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
21 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0109900.html
0 Navigate directly to the URL for a descriptive web page with download links. https://doi.org/10.3334/cdiac/otg.clivar_sr03_2008
0 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/archive/accession/oas/109900
0 Navigate directly to the URL for data access and direct download. https://www.ncei.noaa.gov/archive/accession/download/109900
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Institution web page http://www.utas.edu.au
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.utas.edu.au
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
21 related resource https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/RepeatSections/clivar_p12.html
0 OCADS website https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system
21 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0109900.html
0 Navigate directly to the URL for a descriptive web page with download links. https://doi.org/10.3334/cdiac/otg.clivar_sr03_2008
0 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/archive/accession/oas/109900
0 Navigate directly to the URL for data access and direct download. https://www.ncei.noaa.gov/archive/accession/download/109900
0 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). ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0058/0109900/
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Institution web page http://www.utas.edu.au
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.utas.edu.au
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
21 related resource https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/RepeatSections/clivar_p12.html
0 OCADS website https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system
21 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0109900.html
0 Navigate directly to the URL for a descriptive web page with download links. https://doi.org/10.3334/cdiac/otg.clivar_sr03_2008
0 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/archive/accession/oas/109900
0 Navigate directly to the URL for data access and direct download. https://www.ncei.noaa.gov/archive/accession/download/109900
0 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). ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0058/0109900/
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Institution web page http://www.utas.edu.au
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.utas.edu.au
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
21 related resource https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/RepeatSections/clivar_p12.html
0 OCADS website https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system
21 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0109900.html
0 Navigate directly to the URL for a descriptive web page with download links. https://doi.org/10.3334/cdiac/otg.clivar_sr03_2008
0 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/archive/accession/oas/109900
0 Navigate directly to the URL for data access and direct download. https://www.ncei.noaa.gov/archive/accession/download/109900
0 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). ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0058/0109900/
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Institution web page http://www.utas.edu.au
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.utas.edu.au
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
21 related resource https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/RepeatSections/clivar_p12.html
0 OCADS website https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system
21 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/data/oceans/ncei/ocads/metadata/0109900.html
0 Navigate directly to the URL for a descriptive web page with download links. https://doi.org/10.3334/cdiac/otg.clivar_sr03_2008
0 Navigate directly to the URL for a descriptive web page with download links. https://www.ncei.noaa.gov/archive/accession/oas/109900
0 Navigate directly to the URL for data access and direct download. https://www.ncei.noaa.gov/archive/accession/download/109900
0 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). ftp://ftp-oceans.ncei.noaa.gov/nodc/archive/arc0058/0109900/
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Institution web page http://www.utas.edu.au
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.ocean.washington.edu
0 Institution web page http://www.rsmas.miami.edu
0 Institution web page http://www.utas.edu.au
0 Information for contacts at NCEI. https://www.ncei.noaa.gov/contact
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
0 Global Change Master Directory (GCMD). 2025. GCMD Keywords, Version 21. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords
21 related resource https://www.ncei.noaa.gov/access/ocean-carbon-acidification-data-system/oceans/RepeatSections/clivar_p12.html
0 OCADS website https://www.ncei.noaa.gov/products/ocean-carbon-acidification-data-system

Tags

  • silcat
  • cfc-11
  • southern ocean
  • cfc-12
  • doc
  • tcarbn
  • par
  • discrete measurement
  • phspht
  • nitrat
  • profile
  • 09ar20080322
  • oceanography
  • au0806
  • clivar_sr03_2008
  • ctdtmp
  • salnty
  • ctdoxy
  • clivar sr03
  • ctdsal
  • alkali
  • fluoro
  • cfc113
  • tdn
  • oxygen
  • ocean carbon and acidification data system (ocads) project

Topics

Categories