Modelling of broad band ultraviolet clearness index distributions for Cordoba, Spain

The biological and photochemical effects of ultraviolet (UV) solar radiation and solar energy applications make it really important to characterize this component. In this report, for different ranges of optical air mass (mr), we have described and modelled its behaviour, in terms of the UV clearness index. In addition, we have compared it to that of the horizontal solar broadband global irradiance (G), in terms of the clearness index. We have used 5-min measurements registered at a radiometric station located in Cordoba (Spain) and analyzed the relative probability distributions as an approximation of the instantaneous ones. We may conclude that, although both have significant similarities, G distributions are bimodal while UV ones are not. According to that, we have modelled UV solar radiation noting that the fitting parameters depend on mr.