Implications of smaller concentrations of stratospheric OH - A two-dimensional model study of ozone perturbations

There is growing observational evidence that stratospheric OH concentrations are smaller than models have been predicting. Using very recent HOx reaction rate coefficient measurements in a two-dimensional photochemical model, results which support these observations are obtained. As a consequence of smaller OH concentrations, we show that perturbations of stratospheric ozone by NOx (SST emissions and nitrogen fertilizers) may be larger than expected, while perturbations due to added water vapor and chlorine (SSTs and chlorofluoromethanes, respectively) may be smaller.