Using airglow to derive the temperature profile in the Mars atmosphere
- Paper number
IAC-08.E2.2.1
- Author
Ms. Marie-Ève Gagné, University of Toronto, Canada
- Year
2008
- Abstract
Middle-atmospheric (50 - 100 km) temperature measurements of Mars are rare and unreliable because of the high opacity of the atmosphere. The absorption bands of the standard sensors used to infer temperature quantities, i.e. in the thermal infrared region, are mostly saturated due to the high concentration of carbon dioxide (CO 2) in the Martian atmosphere, as the main absorption lines of CO 2 cover most of this spectral region. Airglow measurements provide a highly promising approach for the determination of temperature and atomic-oxygen density over this altitude range given the strong heritage of this technique for Earth observations. Airglow has been observed during the Mariner 6, 7 & 9 missions; the presence of atmospheric airglow features in different spectral regions has recently been confirmed by the measurements of SPICAM on board Mars EXpress 1.
Our study aims to simulate airglow emissions in the Martian atmosphere from the Herzberg I & II and Chamberlain bands. Those emissions are used to sound the temperature of the Martian neutral atmosphere in the aerobreaking altitude region. The simulations are performed with a time-dependent photochemical model that solves for the diurnal changes in composition driven by varying insolation between the ground and 100 km altitude 2. Ultimately, the findings of the study will support the development of an instrument that can be used to derive temperature measurements and atomic-oxygen density from airglow detection.
1 Leblanc, F., J. Y. Chaufray, J. Lilensten, O. Witasse, and J.-L. Bertaux, 2006. Martian dayglow as seen by the SPICAM UV spectrograph on Mars Express. J. Geophys. Res., V.111, No.E09S11.2 García-Muñoz, A., J.C. McConnell, I.C. McDade and S.M.L. Melo, 2005. Airglow on Mars: Some model expectations for the OH Meinel bands and the O 2 -IR atmospheric band. Icarus, V.176, Issue 1, pp. 75-95.
- Abstract document
- Manuscript document
IAC-08.E2.2.1.pdf (🔒 authorized access only).
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