CO<SUB>2</SUB>(ν<SUB>2</SUB>)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere - Archive ouverte HAL Access content directly
Journal Articles Atmospheric Chemistry and Physics Year : 2012

CO22)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere

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A. A. Kutepov
  • Function : Author
C. -Y. She
  • Function : Author
A. K. Smith
  • Function : Author
W. D. Pesnell
  • Function : Author
R. A. Goldberg
  • Function : Author

Abstract

Among the processes governing the energy balance in the mesosphere and lower thermosphere (MLT), the quenching of CO22) 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.
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Dates and versions

insu-03621706 , version 1 (28-03-2022)

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Attribution - CC BY 4.0

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A. G. Feofilov, A. A. Kutepov, C. -Y. She, A. K. Smith, W. D. Pesnell, et al.. CO22)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere. Atmospheric Chemistry and Physics, 2012, 12, pp.9013-9023. ⟨10.5194/acp-12-9013-2012⟩. ⟨insu-03621706⟩
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