ETON 2: Quenching parameters for the proposed precursors of O2(b1Σg+) and O(1S) in the terrestrial nightglow

Abstract

Volume emission profiles of the O2(b1Σg+-X3 Σgt-)(O-O) Atmospheric Band and the O(1S-1D) green line are used together with coordinated measurements of the atomic oxygen concentrations to test the hypothesis that both emissions are excited by Barth type mechanisms. By considering O2(b1Σg+) to be produced from an excited O2 precursor, with O2 as transfer agent, and O(1S) to be formed from a similar precursor with atomic oxygen as the transfer agent, precursor quenching rates are obtained as a function of altitude. These quenching profiles can be well resolved into components corresponding to collisional deactivation by O(3P) and O2 (or N2), and support the suggestion that Barth type mechanisms are involved. Minimum efficiencies for the production of the two precursors in oxygen atom recombination and ratios for the quenching of each by O(3P) and O2 (or N2) are deduced. Differences in the quenching coefficients for the two precursors are discussed. © 1986.