ИСТИНА

The UV-index is a measure of the erythemal effective solar radiation reaching the Earth surface. It was introduced to alert people about the need of sun protection. Therefore the UVindex has to be determined with adequate accuracy. To minimise the risk of too high levels of sunburn the UV-index is determined usually for clear sky conditions. To alert people in time the UV-index forecast is essential. Here the schemes of UV-index forecast for one day in advance are presented. Because the UV-index under clear sky conditions depends on the total ozone column over a given geographic location the UV-index forecast implicates the forecast of the total ozone column. The scheme of ozone forecast is based on satellite data. For the determination of the UV, model calculations using the radiation transfer model TUV of Madronich are implemented. The land snow cover is taken into account.