Electronic kinetics of molecular oxygen in the nightglow

Abstract

Altitude profiles of O2 nightglow emission intensities give information about composition of the atmosphere. Remote measurements of intensities of the emissions from satellites or rockets allow estimation of concentrations of atomic oxygen at the altitudes of the nightglow. Peculiarities of O2 electronic-state kinetics in the nightglow of the atmosphere are studied here. A model of the kinetics based on calculated quenching-rate coefficients for Herzberg states of O2 is suggested. The model considers intramolecular and intermolecular electron-energy transfer processes in molecular collisions as production and loss mechanisms of Herzberg states. The quenching-rate coefficients are applied in the calculation of vibrational populations of O2(A3Σu +), O2(A′3Δu) and O2(c1Σu −) in the nightglow. The function of the distribution of electronically excited molecular oxygen after the process of three-body recombination is estimated using experimental data and a least-squares fitting program. Calculated vibrational populations of A3Σu + and A′3Δu Herzberg states at an altitude of 95 km are compared with results of experimental measurements.