A monitoring network for erythemally-effective solar ultraviolet radiationin Austria: determination of the measuring sites and visualisation of the spatial distribution

In 1997 the Austrian ultraviolet radiation monitoring network was to built up to measure continuously erythemally-effective ultraviolet radiation. For this network the necessary measuring sites had to be selected by an object ive method. Therefore a method was used. based on the decorrelation distanc es, calculated by the daily maximum of the global solar irradiance across t he entire spectrum. For a correlation coefficient of 0.90, de-correlation d istances were found to be in the order of 170 km (East-West) and 40 knit (N orth-South). From this, 7 measuring sites were selected to derive a total c overage of Austria. For the visualisation of the measured crythemally-effective solar radiation an optimum interpolation method was used to calculate the spatial distribu tion. The topography of Austria was used for height correction. The global solar radiation of 39 stations is also used to include the spatial distribu tion of cloud cover and the resulting attenuation of the erythemally-effect ive radiation. The combination of these two data sets provides an accuracy estimation of people's exposure to erythemally-effective UV radiation withi n the mountainous country of Austria.