Excitation of oxygen emissions in the night airglow of the terrestrial planets

Abstract

The excitation, energy transfer and quenching of O 2 (A 3 Σ u +, C 3 Δ u, c 1 Σ u −) and O( 1S) are discussed, taking into account laboratory measurements and observations on the airglow of the Earth, Venus and Mars. The excitation of O( 1S) occurs by the Barth mechanism with O 2(c) as a precursor: the rate coefficient is 2.5 × 10 −12 cm 3 s −1 for υ > 0 and 2.5 × 10 −12 exp( −1100 T ) cm 3 s −1for υ = 0. The O 2(c) can be formed directly by recombination or by O 2(A) and O 2(C) colliding with other molecules; the O 2(c) yield through quenching of these states is about 0.3 in air and about 1.0 in carbon dioxide. The rate coefficients of some processes that control the molecular oxygen bands and the atomic oxygen green line are estimated.