Dhyne, Miguel

Fissiaux, Laurent

Lepère, Muriel

Maldague, Félix

Populaire, Claude

Vandaele, Ann Carine

English

Repository of the University of Namur

Temperature dependence of CO2-broadening coefficients of lines in the 4 band of CH4M. Dhynea, F. Maldaguea, L. Fissiauxa, J.-C. Populairea, A.-C. Vandaele b, M. Lepèrea.a , Laboratoire Lasers et Spectroscopies, PMR, University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium, Tel. +32 81 72 45 84, Fax. +32 81 72 45 45, muriel.lepere@unamur.be.b Institut d’Aéronomie Spatiale de Belgique, Avenue circulaire 3, 1180 Bruxelles, Tel. +32 2 373 04 04, Fax. +32 2 374 84 23, ann-carine.vandaele@aeronomie.bec Address, Tel.: , Fax: , E-mail:Methane is a constituent of some planetary, like Mars, and Earth atmospheres [1]. This is the second most abundant greenhouse gas on our atmosphere [2-4]. In order to retrieve the abundance of methane in atmosphere, we need to have information about their spectral parameters like the collisional broadening coefficient.Using a high resolution tunable diode-laser spectrometer [5], CO2-broadening coefficients have been measured for lines in the 4 band of CH4. The lines have been studied for 7 temperatures ranging from 350 to 650 K.For each line, we have recorded spectra at 4 pressures of the perturber. The collisional halfwidths of line at each pressure and each temperature have been obtained by fitting on the experimental profile, the Voigt [6] lineshape, but also the models developed by Rautian and Sobel'man [7] and by Galatry [8] which take into account a supplementary physical effect (molecular confinement : Dicke effect [9]).The collisional broadening coefficients of each line at each temperature have been deduced as the slope of the best straight line obtained from a linear regression when halfwidths are plotted in function of the perturber gas pressure. From these results, the temperature dependence parameters of each line have been determined.[1] M. J. Mumma, R. E. Novak, M. A. DiSanti, B. P. Bonev, Bulletin of the American Astronomical Society 2003, 35, 937.[2] K. Tsuji, S., Fujikawa, K. Yamada, N. Yoshida, K. Yamamoto, T. Kikugawa, Sensors and Actuators B 2006, 114, 326-333.[3] K. Yamamoto, N. Yoshida, Spectrochim. Acta Part A 2002, 58, 2699-2707.[4] J. Barry McManus, Mark S. Zahniser, David D. Nelson, Leah R. Williams, Charles E. Kolb, Spectrochim. Acta Part A 2002, 58, 2465-2479.[5] L. Fissiaux, G. Blanquet, M. Lepère, J. Quant. Spectrosc. Radiat. Transfer 2012, 113(11), 1233-1239.[6] B.-H. Armstrong, J. Quant. Spectrosc. Radiat. Transfert 1967, 7, 61.[7] S.G. Rautian, Sobel'man I I, Sov. Phys. Usp. Engl. Trans. 1967, 9, 701-716.[8] L. Galatry, Phys. Rev. 1960, 122, 1218-1224.[9] R.H. Dicke, Phys. Rev. 1953, 89, 472-473.

Temperature dependence of CO2-broadening coefficients of lines in the ν4 band of CH4

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Temperature dependence of CO<sub>2</sub>-broadening coefficients of lines in the ν<sub>4</sub> band of CH<sub>4</sub>

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