In this work we present the results from the analysis of regular solar UV‐B spectral measurements obtained at Thessaloniki (40°N) during a period of three years, from November 1990 through November 1993. The results presented here refer to both clear‐skies (cloudiness ≤3/8) as well as to all‐skies conditions, and to solar zenith angles of 63°±1°. These results support earlier findings of increased solar UV‐B irradiances, under all‐skies conditions, associated with observed ozone decline at the same period. The observed acceleration of the ozone decline‐of about 5 per year‐during the three‐year period resulted to increased solar UV irradiance levels at Thessaloniki by 12.3 per year at 305 nm and 2.7 per year at 325 nm. These figures are slightly modified under all‐skies conditions, and they are in agreement with findings reported independen
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