Revised predictions of the effect on stratospheric ozone of increasing atmospheric N 2O and chlorofluoromethanes: A two-dimensional model study

Abstract

The perturbation of stratospheric ozone caused by a doubling of atmospheric N 2O and by an increase of stratospheric chlorine of about 0.9 ppbv due to continued release of chlorofluoromethanes is simulated with the aid of a two-dimensional photochemical model and new measurements of OH reaction rate coefficients. The global mean O 3 decrease is revised upward from about 8.5% to about 14% for N 2O doubling, but is reduced from about 1.6% to about 0.8% for 0.9 ppbv chlorine increase. The latitude variation of the O 3 perturbations as well as predictions of stratospheric OH abundance are also discussed.