CHANGES IN SOLAR ULTRAVIOLET-RADIATION REACHING THE GROUND DUE TO TROPOSPHERIC AND STRATOSPHERIC OZONE VARIATIONS

Using the surface ozone mixing ratios in Athens, Greece, from the begi nning to the end of the 20th century, an assessment of variations in s olar UV radiation reaching the ground has been made. Employing a simpl e algorithm, the spectral and broadband solar UV radiation reaching th e surface in the Athens area during the period 1979-1991 was calculate d, considering the TOC variations derived from the ''Nimbus-7'' satell ite data. A total ozone reduction of 2.5% per decade during summer tim e causes a 5% increase in UV irradiance.