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| Titel |
CO2(ν2)-O quenching rate coefficient derived from coincidental SABER/TIMED and Fort Collins lidar observations of the mesosphere and lower thermosphere |
| VerfasserIn |
A. G. Feofilov, A. A. Kutepov, C.-Y. She, A. K. Smith, W. D. Pesnell, R. A. Goldberg |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 19 ; Nr. 12, no. 19 (2012-10-02), S.9013-9023 |
| Datensatznummer |
250011491
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| Publikation (Nr.) |
 copernicus.org/acp-12-9013-2012.pdf |
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| Zusammenfassung |
| 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. |
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