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World Data Centres


 Presently, there are six GAW WDCs each responsible for archiving one or more GAW measurement parameters or measurement types. They are operated and maintained by their individual host institutions. They collect, document and archive atmospheric measurements and the associated metadata from measurement stations world-wide and make these data freely available to the scientific community. In some cases, WDCs also provide additional products including data analyses, maps of data distributions, and data summaries.

 The data residing in the WDCs are always subject to change, for example, from new calibrations. For this reason, data providers at individual stations should always be contacted directly for detailed information on such changes. In order that data providers be given appropriate recognition, scientists accessing the data are required to accept the following conditions set forth by the CAS WG and supported by the Thirteenth Session of CAS: "For scientific purposes, access to these data is unlimited and provided without charge. By their use you accept that an offer of co-authorship will be made through personal contact with the data providers or owners whenever substantial use is made of their data. In all cases, an acknowledgement must be made to the data providers or owners and the data centre when these data are used within a publication.


  World Ozone and Ultraviolet Radiation Data Centre

 The World Ozone and Ultraviolet Radiation Data Centre (WOUDC) is one of six World Data Centres which are part of the Global Atmosphere Watch programme of the World Meteorological Organization. The WOUDC data centre is operated by the Meteorological Service of Canada, a branch of Environment Canada.

 Ozone data set categories include total column ozone and vertical profile data from lidar measurements, ozonesonde flights, and the Umkehr technique. Ultraviolet (UV) radiation data set categories include broadband, multiband, and high resolution spectral data types.

 There are over 500 registered stations in the archive from over 150 contributors. Metadata such as station lists with locations, are available from the WOUDC Website.

 Value added data products include total ozone time series graphs and near real-time ozone maps.

 All WOUDC data are made available by using the data search / download, or anonymous FTP access. In addition, the Open Geospatial Consortium web services provide enhanced access to the archive, which provides standards-based-on-demand access to the archive. For more information, please refer to the data access page.

 History of the Data Centre

  • 1960: World Ozone Data Centre (WODC) created
  • 1964: first publication of Ozone Data for the World issued
  • 1992: solar ultraviolet (UV) radiation data is added to the data archives; data centre renamed to World Ozone and Ultraviolet Radiation Data Centre (WOUDC)
  • 1995: initial website and FTP site created
  • 1996: first data CD ROM produced
  • 2006: first data DVD ROM with complete data archive released
  • 2015: website updated, providing modernized mechanisms supporting discovery, visualization, access and management of ozone and UV data

  The World Radiation Data Centre

 The World Radiation Data Centre (WRDC) is located in St. Petersburg at the Main Geophysical Observatory of the Russian Federal Service for Hydrometeorology and Environmental Monitoring. The WRDC was established in 1964, and since that time it centrally collects, archives and publishes radiometric data for the world, to ensure the availability of these data for research purposes by the international scientific community. It issues a periodic bulletin entitled "Solar Radiation and Radiation Balance Data. The World Network."

 The WRDC processes solar radiation data currently submitted from more than 500 stations located in 56 countries and operates an archive with more than 1200 stations listed in its catalogue. The WRDC is the central depository of the measured components such as: global, diffuse and direct solar radiation, downward atmospheric radiation, net total and terrestrial surface radiation (upward), spectral radiation components (instantaneous fluxes), and sunshine duration, on hourly, daily or monthly basis.

 At the present time, recent and current data can be viewed by accessing the WRDC web site. It also contains a list of all stations that have submitted data. As new measurement data are received from National Meteorological Services and other institutions in paper form, on magnetic media or electronically, the WRDC performs a supplementary quality control and requests stations to confirm the data for total quality assurance. The data from GAW sites is represented in a specified directory as tables and as figures including graphs showing relationships between measured and estimated parameters.

  The World Data Centre for Greenhouse Gases 

 The World Data Centre for Greenhouse Gases (WDCGG) was established at the Japan Meteorological Agency (JMA) in October 1990 and collects and distributes data on the mixing ratios of greenhouse (CO2, CH4, CFCs, N2O, etc.) and related reactive (O3, CO, NOx, SO2, VOC, etc.) gases in the atmosphere and the ocean. Simultaneously measured meteorological parameters are also recorded at WDCGG.

 Data contributors submit their data on the Internet in accordance with the Revision of the WDCGG Data Submission and Dissemination Guide (GAW Report No. 188).  As of March 2012, 325 stations from 65 countries submitted observational data for 111 species of greenhouse and related gases to the WDCGG.  The WDCGG periodically publishes the "WMO WDCGG DVD" and "WMO WDCGG Data Summary".  The "DVD" contains hourly, daily, monthly and annual mean values, as well as information on site environment, measurement procedures, and calibration techniques. Information on contact persons, methods of measurement and calibration at the observation stations is also made available, and all data can be accessed from the WDCGG website.  The "Data Summary" includes averaged results from the past and present conditions on regional, and global scales.

The World Data Centre for Aerosols

 The World Data Centre for Aerosols (WDCA) operated by the European Union's Joint Research Centre, Ispra, Italy, has recently moved to the Norwegian Institute for Air Research. It is established to archive aerosol related observations made under GAW. A wide variety of aerosol parameters have been recommended by the GAW Scientific Advisory Group for Aerosols as suitable for measurement and archiving at GAW Regional and Global stations.

GAW aerosol long-term observation core parameters:

  • Physical Properties:
    • particle number concentration (size integrated)
    • particle number size distribution
    • particle mass concentration (two size fractions)
    • cloud condensation nuclei number concentration (at various super-saturations)
  • Optical Properties:
    • light scattering coefficient (various wavelengths)
    • light hemispheric backscattering coefficient (various wavelengths)
    • light absorption coefficient (various wavelengths)
  • Chemical Properties:
    • mass concentration of major chemical components (two size fractions)
  • Column and Profile:
    • aerosol optical depth (various wavelengths)
    • vertical profile of aerosol backscattering coefficient
    • vertical profile of aerosol extinction coefficient

Additional parameters recommended for long-term or intermittent observation:

  • dependence of aerosol properties on relative humidity
  • detailed, size segregated chemical composition

 The extent of the observation programme varies between observatories networked in GAW. The observations are reported by the GAW observatories on a voluntary basis, while the station infrastructure is a contribution of the participating national authorities to the GAW Programme.


  World Data Centre for Precipitation Chemistry

 The World Data Centre for Precipitation chemistry (WDCPC) is presently operated by Mr Van Bowersox in association with the Illinois State Water Survey and the US National Oceanic and Atmospheric Administration (NOAA). Mr. Bowersox, formerly the Program Coordinator of the US National Atmospheric Deposition Program, assumed this position in January 2009. The WDCPC was initiated in 1992 at the State University of New York in Albany, New York, where it operated jointly with the Quality Assurance/Science Activity Centre (QA/SAC) for the Americas. This joint arrangement of the WDCPC and the QA/SAC-Americas continues unchanged.

 The WDCPC seeks to provide on-line access to GAW precipitation chemistry data by creating links to major regional precipitation chemistry programs that offer their own data ports, and by archiving and making accessible data from other GAW global and regional sites not affiliated with one of these major networks. The WDCPC will provide laboratory contact information, as well as pictures and links to monitoring site information. Other unique and
historic data also will be archived on the WDCPC Web site. This site operates in close coordination with the QA/SAC-Americas, which conducts semi-annual laboratory intercomparison studies. These studies, designed to help ensure the known and high quality of GAW precipitation chemistry measurements, provide data for assessing laboratory performance. Performance charts are presented as "ring diagrams." These diagrams uniquely enable data users to visually evaluate laboratory accuracy for individual chemical species and make decisions about the appropriateness of data for their own studies.

 Conventional FTP access to the WDCPC and QA/SAC data sets will require username and password. Together the links to major networks and the online data archives will give users access to more than 200 global, regional, and contributing stations worldwide.









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