Ozone photodissociation in the Hartley band: A statistical description of the ground state decomposition channel O2(X 3Σ−g)+O(3P)

Abstract

Ozone photodissociation in the Hartley band O3+hν→O(3P)+O2(X 3Σ−g) is simulated with a statistical model. In the model, energy is partitioned at a decoupling distance which is located at a position with nonzero potential energy on a repulsive and dissociative potential energy surface. Introduction of the repulsive potential on which dissociation takes place, and the choice of decoupling distance is shown to be of crucial importance for the final energy distributions, and in particular it determines the amount of energy left in translation. The model is shown to give good agreement with experimental vibrational and translational energy distributions, while the rotational distributions predicted by the model seem less peaked than experimental data. Vibrational state distributions are calculated for different dissociation wavelengths in the Hartley band (200–310 nm), and they are concluded to deviate substantially from distributions previously used in atmospheric modeling. The statistical approach is compared to impulsive and statistical models, and also related to recent quantum mechanical calculations.