Ultraviolet index estimated in Badajoz (Spain) using a multiband radiometer

摘要

The Ultraviolet Index (UVI) obtained by a multichannel radiometer GUV‐2511 (BiosphericalInstruments Inc.) is analyzed in this paper. This instrument has been recently installed in theradiometric station of Extremadura University in Badajoz (Spain). The UV Index has been calculatedby a linear combination of three and four GUV channel irradiance values. In order to test theseresults, simultaneous values of UVI were calculated with the data provided by a well calibratedbroadband UVS‐E‐T instrument co‐located side by side the GUV multichannel. This radiometer has aspectral response that is adapted to the erythemal (sunburn) action spectrum of the human skin.One‐minute simultaneous values of both instruments have been used to calculate ultraviolet Index(UVI). Although the measurement period is limited, it covers all sky conditions, from cloud‐free toovercast days. UVI calculated with the whole data set by both methods are well correlated, but not aswell as using only clear day data. It was observed that GUV underestimates UVI values (mean biaserror, MBE=?18.9%), being the four channel method the most successful.