ON THE OZONE-RELATED CHANGES IN BIOLOGICALLY-ACTIVE ULTRAVIOLET-RADIATION REACHING THE EARTHS SURFACE

With the depletion of the stratospheric ozone layer, the atmosphere be came more transparent to solar ultraviolet radiation. The penetration of this radiation is also affected by tropospheric ozone, aerosol, and clouds. Increases in tropospheric ozone may have decreased the levels of the solar ultraviolet radiation in industrialized regions by amoun ts comparable to the increases estimated from stratospheric ozone chan ge. Using the surface ozone mixing ratios monitored in Athens, Greece from the beginning to the end of the 20th century, the estimation of t he reduction of the solar ultraviolet reaching the ground is attempted .