Prediction of UV-B dosage at the surface

Stratospheric ozone reduction is expected to result in increased UV radiation at the surface. The UV region most sensitive to ozone amount is that between 280 and 315 nm and is known as UV-B. One response to the concern about increased UV-B has been the development of systems to provide public UV forecasts. This paper reviews the factors that influence UV-B at the ground and describes the basic radiative transfer concepts that form the basis for forecast schemes. The role of clouds and atmospheric aerosols are also reviewed. The standard definition for the UV index (UVI) currently used for public forecasts is defined followed by a brief summary of three operational UVI schemes.