Two-dimensional model studies of the impact of aircraft exhaust emissions on tropospheric ozone

The potential effects of aircraft operations in the troposphere were investigated with a two-dimensional (latitude-altitude) transport-kinetics model. There appears to be reasonable agreement between the present and previous studies that aircraft operations may have already increased ozone concentrations in the upper troposphere by up to a few per cent or so. The corresponding increases in the total ozone column amount to a few tenths of a per cent and may well have partially offset any decrease due to the release of chlorofluorocarbons 11 and 12.