Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

Poster session, J8 171CO 2 broadening and shift coefficients for the 2–0 band of COand influence on the inversion of SOIR spectraM. Tudorie, 1 S. Robert, 2 T. Földes, 1 A. Mahieux, 2 R. Drummond, 2V. Wilquet, 2 A. C. Vandaele 2 and J. Vander Auwera 11 Service de Chimie Quantique et Photophysique, C.P. 160/09, Université Libre deBruxelles, 50 avenue F.D. Roosevelt, B-1050 Brussels, Belgium, jauwera@ulb.ac.be;2 Planetary Aeronomy Division, Belgian Institute for Space Aeronomy, 3 AvenueCirculaire, B-1180 Brussels, Belgium, severine.robert@aeronomie.beCarbon monoxide is present in the atmosphere of Venus and Mars, as observed for thefirst time by Connes et al. 1 and Kaplan et al., 2 respectively. More recent CO spectrawere recorded in the 2.2 and 4.3 μm region 3,4 by the SOIR (Solar Occultation in theInfraRed) instrument onboard the ESA Venus Express spacecraft 5 and by the PFS(Planetary Fourier Spectrometer) instrument onboard the ESA Mars Expressspacecraft. 6 As carbon dioxide is the predominant species in these atmospheres,retrievals of CO concentrations from SOIR spectra require knowledge of CO 2broadening and shift coefficients 7 and their temperature dependence.We recorded spectra of CO/CO 2 mixtures at 284, 272, 255 and 240 K and totalpressures between 120 and 900 Torr, using a Bruker IFS125HR Fourier transformspectrometer. We measured CO 2 pressure broadening and shift coefficients of lines inthe 2–0 band of CO near 2.3 μm, using a multi-spectrum non-linear least squares fittingprocedure. 8 The analysis put forward the necessity to consider speed dependenceeffects, and possibly line mixing effects, on the Voigt profile.With a resolution of 0.12 cm –1 , the highest onboard Venus Express, SOIR may besensitive enough to study line profiles. The line broadening parameters measured in thepresent work have been used to fit SOIR spectra with the ASIMAT code. 9 The results interms of retrieved densities and temperatures will be compared with those obtainedusing HITRAN2008. 10Tudorie M.Robert S.Foldes T.Mahieux A.Drummond R.Wilquet V.Vandaele A.C.Vander Auwera J.References[1] P. Connes, J. Connes, L.D. Kaplan, W.S. Benedict, Astrophys. J. 152, 731, 1968.[2] L.D. Kaplan, J. Connes, P. Connes, Astrophys. J. 157, L187, 1969.[3] J.L. Bertaux, A.C. Vandaele et al., Nature 450, 646, 2007.[4] A.C. Vandaele, M. De Mazière et al., J. Geophys. Res. 113, E00B23, 2008.[5] D. Nevejans, E. Neefs et al., Appl. Opt. 45, 5191, 2006.[6] G. Sindoni, V. Formisano, A. Geminale, Planet. Space Sci. 59, 149, 2011.[7] K. Sung and P. Varanasi, JQSRT 91, 319, 2005.[8] M. Tudorie, T. Földes, A.C. Vandaele, J. Vander Auwera, JQSRT 113, 1092, 2012.[9] A. Mahieux, A.C. Vandaele et al., J. Geophys. Res. 115, E12014, 2010.[10] L.S. Rothman, I. Gordon et al., JQSRT 110, 533, 2009.AcknowledgmentsFinancial support from the Fonds de la Recherche Scientifique (F.R.S.-FNRS, Belgium,contract FRFC), the Action de Recherches Concertées of the Communauté française deBelgique, the Belgian Federal Science Policy Office (contract SD/CS/07A, AdvancedExploitation of Ground-Based Measurements for Atmospheric Chemistry and Climateapplications – II), and the European Space Agency (ESA, PRODEX program, contracts C90268, 90113, and 17645) is gratefully acknowledged.