Tropospheric ozone

Abstract

Photochemical equilibrium models have been used to study the effect of recent revisions in important chemical reaction rates on the calculated tropospheric ozone concentration. Reasonable agreement with observed values is obtained if the NO(x) background is approximately 0.02 to 0.03 ppb, about an order of magnitude less than used in many previous model studies, but consistent with present nitrogen budget considerations and with observations of NO2. Chemical production and loss of ozone may dominate transport terms depending on values of key chemical rate constants and of the NO(x) background. This is consistent with the structure observed in the mean annual latitudinal distribution of ozone since ozone is its own chemical precursor and regions of enhanced stratosphere-troposphere exchange are also regions of enhanced photochemical activity.