The ionospheric oxygen green airglow: Electron temperature dependence and aeronomical implications

The laboratory measurement of processes involved in terrestrial airglows is essential in developing diagnostic tools of the dynamics and photochemistry of the upper atmosphere. Dissociative electron recombination of O⁺₂ in the ionospheric F-region is expected to produce both O(¹D) and o(¹S) which are the sources of the 630.0 nm red airglow and the 557.7 nm green airglow lines, respectively. We present both theoretical and experimental evidence, the latter from a heavy ion storage ring technique, that the O(¹S) quantum yield from O⁺₂ (v = 0) is a strong function of the electron temperature due to a molecular resonance phenomenon. At present the O⁺₂(v = 0) theoretical and laboratory recombination data cannot explain rocket observations of the ionospheric green and red airglows [Takahashi et al. 1990; Sobral et al. 1992].