ABSTRACT
The most common ground-based method of measuring total column ozone is the Dobson spectrophotometer, which determines the differences in atmospheric attenuation of solar ultraviolet (UV) radiation across spectral lines centred on 320 nanometers. Satellite measurements are also being made of both total column ozone and vertical variation, using ultraviolet radiation back-scattered from the atmosphere. The discovery of ozone depletion in the Antarctic in 1985, and the recognition of the potentially severe consequences for the UV climate, resulted in a fast piece of international pollution control legislation. The ozone layer absorbs UV, and it is the potential increase of ground level UV that is seen as the main environmental hazard of ozone depletion. Even with ozone depletion, UV fluxes in the Antarctic are less than those at the equator. The greatest reductions of column ozone and associated increases in UV have occurred in Antarctica, where plant densities are low.
