Articles | Volume 15, issue 4
Technical note
17 Feb 2015
Technical note |  | 17 Feb 2015

Technical Note: On the possibly missing mechanism of 15 μm emission in the mesosphere–lower thermosphere (MLT)

R. D. Sharma

Related subject area

Subject: Radiation | Research Activity: Atmospheric Modelling | Altitude Range: Mesosphere | Science Focus: Chemistry (chemical composition and reactions)
Photochemical modeling of molecular and atomic oxygen based on multiple nightglow emissions measured in situ during the Energy Transfer in the Oxygen Nightglow rocket campaign
Olexandr Lednyts'kyy and Christian von Savigny
Atmos. Chem. Phys., 20, 2221–2261,,, 2020
Short summary
Influence of a Carrington-like event on the atmospheric chemistry, temperature and dynamics
M. Calisto, P. T. Verronen, E. Rozanov, and T. Peter
Atmos. Chem. Phys., 12, 8679–8686,,, 2012
Influence of Galactic Cosmic Rays on atmospheric composition and dynamics
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Cited articles

Allen, D. C., Scragg, T., and Simpson, C. J. S. M.: Low temperature fluorescence studies of the bend-stretch mode of CO2, Chem. Phys., 51, 279–278, 1980.
Bougher, S. W., Hunten, D. M., and Roble, R. G.: CO2 cooling in the terrestrial planet thermospheres, J. Geophys. Res. 99, 14609–14622, 1994.
Bougher, S. W., Engel, S., Roble, R. G., and Foster, B.: Comparative terrestrial planet thermospheres 2. Solar cycle variations of global structure and winds at equinox, J. Geophys. Res., 104, 16591–16611, 1999.
Burtt, K. D. and Sharma, R. D.: Near-resonant energy transfer from vibrationally excited OH to N2, J. Chem. Phys., 128, 124311,, 2008a.
Burtt, K. D. and Sharma, R. D.: Near-resonant energy transfer from vibrationally excited OH(v), v=9, 8, 1 to CO2, Geophys. Res. Lett., 35, L18102,, 2008b.
Short summary
This paper investigates the discrepancy between the rate coefficients for the deactivation of the bending mode of CO2 by atomic oxygen, a process of great importance in the energy budget of the mesosphere and the lower thermosphere, measured in the laboratory and arrived at by space-based measurements. It is concluded that super-thermal rotational levels of N2, produced by the impact of hot O atoms or by N + NO reaction, have the potential to provide the unknown mechanism.
Final-revised paper