Solar UV-B irradiance and total ozone in Italy: Fluctuations and trends

Solar UV irradiance spectra (290-325 nm) together with daily total ozone co lumn observations have been collected since 1992 by means of Brewer spectro photometers at two Italian stations (Rome and Ispra). The available Brewer irradiance data, recorded around noon and at fixed solar zenith angles, tog ether with the output of a radiative transfer model (the STAR model) are pr esented and analyzed. The Bower irradiance measurements and total ozone flu ctuations and anomalies are investigated, pointing out the correlation betw een the high-frequency O-3 components and irradiance at 305 nm. In addition , the total ozone long time series of Arosa (170 km apart from Ispra) and V igna di Valle (very close to Rome) are analyzed to illustrate evidence of t emporal variations and a possible trend.