Modeling and measurements of UV-B irradiance in cloudy conditions

Abstract

The authors examined the temporal and spatial variation of UV-B erythemal irradiance under cloudy stratocumulus conditions. A three-dimensional cloud model was constructed which had fractal properties in the horizontal. Fractal parameters were derived from 98 aircraft measurements in nor thwest Tasmania. Modelled radiation was compared with spatial sky radiance measurements using a Variable Sky Platform. Temporal measurements of irradiance were also compared with model predictions. In both areas both model and measurements agree well.