Author(s)

Wolfgang Junkermann

Abstract

UV-Actinic Flow in the Lower Troposphere: Results from Flight Experiments Guest contribution Wolfgang Junkermann Fraunhofer Institutfur atmosphdrische Umweltforschung, Kreuzeckbahnstr. 19 D-82467 Garmisch-Partenkirchen, Germany Tropospheric UV radiation transfer is affected by clouds, aerosols or the changing ground albedo. Cloud and aerosol properties (albedo and scattering coefficients) depend on droplet or particle size distribution, the angle of incident light and, partially the chemical composition. Ground albedo varies between a few to nearly 100 percent. Most of the cloud and aerosol variability can be found in the lower troposphere up to a few kilometres, dense aerosol layers occur mostly in the lower two kilometres. In the upper troposphere attenuation and scattering by aerosols is of minor importance and the presence of clouds with their highly reflective surfaces is the mai

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