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 Å was conducted over White Sands Missile Range on 22 October 1984. A 1 4 m spectrometer operating at 3.5 Å 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 (A3Σu+-X3Σg-) 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 (A3Σu+) vibrational distributions indicate that at low altitudes, the higher vibrational levels ( v ́ > 6) 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 (A3Σg+) 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. © 1990.