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www.ann-geophys.net/22/3305/2004/
doi:10.5194/angeo-22-3305-2004
© European Geosciences Union 2004
Nightglow vibrational distributions in the A3Σu+ and A'3Δu states of O2 derived from astronomical sky spectra
1Molecular Physics Laboratory, SRI International, 333 Ravenswood Avenue, Menlo Park CA 94025, USA
2Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, USA
Abstract. Astronomical sky spectra from the Keck I telescope on Mauna Kea have been used to obtain vibrational distributions in the O2A3Σu+) and O2(A'3Δu) states from rotationally-resolved Herzberg I and Chamberlain band emissions in the terrestrial nightglow. The A3Σu+ distribution is similar to that presented in earlier publications, with the exception that there is significant population in the previously undiscerned v=0 level. The vibrational distributions of the A'3Δu and A3Σu+ states are essentially the same when comparison is made in terms of the level energies. The intensity of Chamberlain band emission at the peak of the distribution is about one-fourth that of the Herzberg I emission, as previously shown, and may be related primarily to radiative efficiency. The peaks in both population distributions are about 0.25eV below the O(3P)+O(3P) dissociation limit. We compare these Herzberg state distributions with that of the O2(b1Σg+) state, concurring with others that the intense nightglow emission associated with b1Σg+(v=0) is a reflection of direct transfer from the Herzberg states. This process takes place following O2 collisions, with simultaneous production of very high a1Δg and b1Σg+ vibrational levels.
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Citation: Slanger, T. G., Cosby, P. C., Huestis, D. L., and Widhalm, A. M.: Nightglow vibrational distributions in the A3Σu+ and A'3Δu states of O2 derived from astronomical sky spectra, Ann. Geophys., 22, 3305-3314, doi:10.5194/angeo-22-3305-2004, 2004. Bibtex EndNote Reference Manager XML
