Koepke, P., M. Hess, I. Schult, and E.P. Shettle (1997): Global Aerosol Data Set, Report No. 243, Max-Planck-Institut für Meteorologie, Hamburg, ISSN 0937-1060.

For climate change investigations it is necessary to include the influence of aerosol particles with their temporally and spatially variable properties in addition to the known effects of greenhouse gases. Global fields of all optical parameters necessary for an estimate of the radiative forcing by aerosol particles and to quantify the resulting climate effects are not available from measurements due to the multiple influence parameters. Therefore, aerosol data existing from different measurements and more extensive models have been compiled into the Global Aerosol Data Set (GADS).

In the GADS presented here, the atmospheric aerosol particles are described by 10 main aerosol components which are representative for the atmosphere and characterised through their size distribution and their refractive index depending on the wavelength. These aerosol particles are based on components resulting from aerosol emission, formation and removal processes within the atmosphere, so that they exist as mixture of different substances, both external and internal. Typical components include water-soluble, water-insoluble, soot, sea-salt and mineral. The sea-salt particles are defined in two classes and the mineral particles in four.

For the chosen components the radiative properties are calculated by means of Mie theory at wavelengths between 0.3 and 40 µm and for 8 values of relative humidity. In addition to the optical properties, the global aerosol distribution of each defined aerosol component including the vertical profile has been determined by the GADS on a 5°x5° latitude-longitude grid for winter and summer. This permits the determination of the radiative properties and mass concentration of the resulting externally mixed aerosols at each grid point on the globe.