Atomic oxygen is a chemically active trace gas and a critical component of the energy balance of the mesosphere and lower thermosphere (MLT). By sequentially applying continuity equations of low degree, a new model representing the airglow and photochemistry of oxygen in the MLT is implemented, enabling comparisons with airglow observations at each step. The most effective data sets required to derive the abundance of atomic oxygen are the O₂ atmospheric band emission, temperature, N₂ and O₂.

This paper investigates the discrepancy between the rate coefficients for the deactivation of the bending mode of CO2 by atomic oxygen, a process of great importance in the energy budget of the mesosphere and the lower thermosphere, measured in the laboratory and arrived at by space-based measurements. It is concluded that super-thermal rotational levels of N2, produced by the impact of hot O atoms or by N + NO reaction, have the potential to provide the unknown mechanism.