A method to generate near real time UV-Index maps of Austria

[摘要] A method is presented that combines individual ground based ultraviolet (UV)measurements and satellite data from MSG (Meteosat Second Generation) togenerate a UV-Index map all over the region of Austria. Cloud modificationfactors (CMFs) gathered from satellite images give an area wide informationof the cloud situation but compared to ground based measurements significantdiscrepancies have been found. These discrepancies are especially large forhigh mountain stations but also for low altitude sites differences betweensatellite derived and ground based data in the order of 15% have been found.To overcome these discrepancies a correction procedure based on thecorrelation of both data sets at the pixel of the measurement stations isdeveloped. The uncertainty of the final UV-Index map is evaluated exemplarilyfor the pixel of the measurement sites Bad Vöslau and München byeliminating the information of both sites from the UV-Index map generationprocess and comparing afterwards calculated and measured results. More than5000 maps for all weather conditions have been evaluated leading to a meanagreement of 1.02 (standard deviation ±0.31, Bad Vöslau) and 1.01(standard deviation ±0.34, München) between calculated and measuredUV-Indexes.

[学科分类] 大气科学