A vibrational analysis of the O2 (A3[Sigma]+u) Herzberg I system using rocket data

An observation of the u.v. nightglow between 2670 and 3040 A was conducted over White Sands Missile Range on 22 October 1984. A 1/4 m spectrometer operating at 3.5 A resolution viewed the Earth's limb at tangent heights between 90 and 110 km for 120 s. A total of 41 spectral scans of the nightglow were obtained with the brightest feature being the O2 (A3[Sigma]u+-X3[Sigma]g-) Herzberg I bands. The data were sorted into two groups, one from the top side of the layer and one containing the emission peak, and compared with synthetic spectra. The deduced O2 (A3[Sigma]u+) vibrational distributions indicate that at low altitudes, the higher vibrational levels were relatively depleted; however, the magnitude of the vibrational shift is much less than that predicted from theories of vibrational relaxation. It is shown that increasing the electronic quenching of O2 (A3[Sigma]g+) with respect to the vibrational quenching can reduce the vibrational shift in the model and qualitatively explain the observations; however, several details of the vibrational distribution are not well reproduced.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28345/1/0000105.pd