Titan's surface and atmosphere from Cassini/VIMS data with updated methane opacity

International audience; We present an analysis of Titan data acquired by the Cassini Visual and Infrared Mapping Spectrometer (VIMS), making use of recent improvements in methane spectroscopic parameters in the region 1.3-5.2 μm. We first analyzed VIMS spectra covering a 8 × 10-km2 area near the Huygens landing site in order to constrain the single scattering albedo (ω0) of the aerosols over all of the VIMS spectral range. Our aerosol model agrees with that derived from Huygens Probe Descent Imager/Spectral Radiometer (DISR) in situ measurements below 1.6 μm. At longer wavelengths, ω0 steadily decreases from 0.92 at 1.6 μm to about 0.70 at 2.5 μm and abruptly drops to about 0.50 near 2.6 μm…

Simulations of Titan Observations in the 1.58 Micron Transparency Window with High-Resolution, Low Temperature CRDS Spectra

Le méthane dans l'atmosphère de Titan. De la spectroscopie fondamentale à la planétologie

Le méthane (CH4) joue sur Tian, le plus gros satellite de Saturne, un rôle similaire à celui de l'eau sur Terre. Il y est de plus à l'origine d'une chimie organique complexe. La spectroscopie étant la technique privilégiée pour mesurer le CH4 dans les atmosphères planétaires, des modèles précis de l'absorption de la lumière par cette molécule doivent être développés. Les résultats récents obtenus dans ce domaine à l'Institut Carnot de Bourgogne, en collaboration étroite avec des planétologues, permettent notamment de contribuer à l'interprétation des résultats de la mission Cassini-Huygens.

The 2009 Edition of the GEISA Spectroscopic Database

The updated 2009 edition of the spectroscopic database GEISA (Gestion et Etude des Informations Spectroscopiques Atmosphériques; Management and Study of Atmospheric Spectroscopic Information) is described in this paper. GEISA is a computer-accessible system comprising three independent sub-databases devoted, respectively, to: line parameters, infrared and ultraviolet/visible absorption cross-sections, microphysical and optical properties of atmospheric aerosols. In this edition, 50 molecules are involved in the line parameters sub-database, including 111 isotopologues, for a total of 3,807,997 entries, in the spectral range from 10-6 to 35,877.031cm-1.The successful performances of the new …

Corrigendum to "Titan's surface and atmosphere from Cassini/VIMS data with updated methane opacity" [Icarus 226 (2013) 470-486]

0019-1035/$ see front matter 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.icarus.2013.07.015 DOI of original article: http://dx.doi.org/10.1016/j.icarus.2013.05.033 ⇑ Corresponding author. Address: LESIA, Observatoire de Paris, Section de Meudon, 92195 Meudon Cedex, France. Fax: +33 145072806. E-mail address: bruno.bezard@obspm.fr (B. Bezard). 1 Present address: Foundation ‘‘La main a la pâte’’, Montrouge, France. M. Hirtzig , B. Bezard a,⇑, E. Lellouch , A. Coustenis , C. de Bergh , P. Drossart , A. Campargue , V. Boudon , V. Tyuterev , P. Rannou , T. Cours , S. Kassi , A. Nikitin , D. Mondelain , S. Rodriguez , S. Le Mouelic g

Methane in Titan's atmosphere: from fundamental spectroscopy to planetology

The methane molecule (CH4) is relatively abundant in the Universe and in particular in our Solar System. On Earth, it is the main compound of natural gas and is also the second greenhouse gas of anthropic origin. On Saturn's satellite Titan it plays a role similar to water on Earth and leads to a complex chemistry.

Le méthane dans l’atmosphère de Titan - De la spectroscopie fondamentale à la planétologie

Le methane (CH4) joue sur Tian, le plus gros satellite de Saturne, un role similaire a celui de l'eau sur Terre. Il y est de plus a l'origine d'une chimie organique complexe. La spectroscopie etant la technique privilegiee pour mesurer le CH4 dans les atmospheres planetaires, des modeles precis de l'absorption de la lumiere par cette molecule doivent etre developpes. Les resultats recents obtenus dans ce domaine a l'Institut Carnot de Bourgogne, en collaboration etroite avec des planetologues, permettent notamment de contribuer a l'interpretation des resultats de la mission Cassini-Huygens.

Applications of a New Methane Linelist to the Modeling of Titan's Spectrum in the 1.58 Micron Window

International audience

First Applications of New Methane Linelists to the Modelling of Titan's Spectrum in the 1.58 and 1.28 Micron Windows

Application of new methane linelists to Cassini and Earth-based data of Titan

International audience

Applications of a new set of methane line parameters to the modeling of Titan's spectrum in the 1.58 μm window

International audience; In this paper we apply a recently released set of methane line parameters (Wang et al., 2011) to the modeling of Titan spectra in the 1.58 mu m window at both low and high spectral resolution. We first compare the methane absorption based on this new set of methane data to that calculated from the methane absorption coefficients derived in situ from DISR/Huygens (Tomasko et al., 2008a; Karkoschka and Tomasko, 2010) and from the band models of Irwin et al. (2006) and Karkoschka and Tomasko (2010). The Irwin et al. (2006) band model clearly underestimates the absorption in the window at temperature-pressure conditions representative of Titan's troposphere, while the Ka…

Methane and carbon monoxide infrared emissions observed at the Canada-France-Hawaii Telescope during the collision of comet SL-9 with Jupiter

Observations with the Fourier Transform Spectrometer were conducted in spectral ranges from 1.6 to 4.7 µm from July 17 to 21 (UT) on the hot plumes appearing on the limb as well as hours or days after the impacts. We present here an analysis of the methane emission observed at 3.3 µm some 10 min after the C impact, indicating the presence of a very small (less than 100 km wide) hot region with temperatures in the 750–1500 K range within the 0.1- to 0.01-mbar region. We also report the detection of CO emission at 4.7 µm 4.5 hrs after the L impact, indicative of a temperature of 274±10 K at the ∼1016 CO molec cm−2 level. The observations suggest that the stratospheric temperature decreases wi…