Publication


A. G. Feofilov, et al.
CO2(ν2)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere
Atmospheric Chemistry and Physics, 12(19), 9013-9023, 2012; doi: 10.5194/acp-12-9013-2012
CO2 O13C18O O13CO OC17O OC18O
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Abstract


Among the processes governing the energy balance in the mesosphere and lower thermosphere (MLT), the quenching of CO2(ν2) vibrational levels by collisions with O atoms plays an important role. However, there is a factor of 3–4 discrepancy between the laboratory measurements of the CO2-O quenching rate coefficient, kVT, and its value estimated from the atmospheric observations. In this study, we retrieve kVT in the altitude region 85–105 km from the coincident SABER/TIMED and Fort Collins sodium lidar observations by minimizing the difference between measured and simulated broadband limb 15 μm radiation. The averaged kVT value obtained in this work is 6.5 ± 1.5 × 10−12 cm3 s−1 that is close to other estimates of this coefficient from the atmospheric observations. However, the retrieved kVT also shows altitude dependence and varies from 5.5 ± 1.1 × 10−12 cm3 s−1 at 90 km to 7.9 ± 1.2 × 10−12 cm3 s−1 at 105 km. Obtained results demonstrate the deficiency in current non-LTE modeling of the atmospheric 15 μm radiation, based on the application of the CO2-O quenching and excitation rates, which are linked by the detailed balance relation. We discuss the possible model improvements, among them accounting for the interaction of the "non-thermal" oxygen atoms with CO2 molecules.

Reference


@article{acp-12-9013-2012,
  author = "A. G. Feofilov and A. A. Kutepov and C.-Y. She and A. K. Smith and W. D. Pesnell and R. A. Goldberg",
  title = "CO2(ν2)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere",
  year = 2012,
  journal = "Atmospheric Chemistry and Physics",
  volume = 12,
  number = 19,
  pages = "9013-9023",
  month = "Oct",
  keywords = "CO2, O13C18O, O13CO, OC17O, OC18O",
  doi = "10.5194/acp-12-9013-2012",
  url = "https://www.atmos-chem-phys.net/12/9013/2012/"
}
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