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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.








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