Water vapor in Titan’s stratosphere from Cassini CIRS far-infrared spectra
| Autor: | Nicholas A Teanby, Carrie M. Anderson, G. Bampasidis, Emmanuel Lellouch, F. M. Flasar, Valeria Cottini, Gordon L. Bjoraker, Richard Achterberg, N. Gorius, Patrick G. J. Irwin, R. de Kok, Bruno Bézard, Athena Coustenis, Donald E. Jennings, Conor A. Nixon |
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| Přispěvatelé: | NASA Goddard Space Flight Center (GSFC), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), School of Earth Sciences [Bristol], University of Bristol [Bristol], Science Systems and Applications, Inc. [Lanham] (SSAI), SRON Netherlands Institute for Space Research (SRON), Clarendon Laboratory [Oxford], University of Oxford [Oxford], University of Oxford |
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Atmospheres
010504 meteorology & atmospheric sciences Satellites Atmospheric sciences 01 natural sciences symbols.namesake Far infrared 0103 physical sciences Mixing ratio Radiative transfer Atmosphere of Titan 010303 astronomy & astrophysics Stratosphere Spectroscopy ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences [PHYS]Physics [physics] Satellites Atmospheres Astronomy and Astrophysics Spectral bands 13. Climate action Space and Planetary Science symbols Atmospheres Composition Environmental science Titan (rocket family) Titan [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Water vapor Composition |
| Zdroj: | Icarus Icarus, Elsevier, 2012, 220 (2), pp.855-862. ⟨10.1016/j.icarus.2012.06.014⟩ Icarus, 2012, 220 (2), pp.855-862. ⟨10.1016/j.icarus.2012.06.014⟩ Icarus 220 (2012) 2 Icarus, 220(2), 855-862 |
| ISSN: | 0019-1035 1090-2643 |
| Popis: | Here we report the measurement of water vapor in Titan's stratosphere using the Cassini Composite Infrared Spectrometer (CIRS, Flasar, F.M. et al. [2004]. Space Sci. Rev. 115, 169-297). CIRS senses water emissions in the far infrared spectral region near 50μm, which we have modeled using two independent radiative transfer codes (NEMESIS (Irwin, P.G.J. et al. [2008]. J. Quant. Spectrosc. Radiat. Trans. 109, 1136-1150) and ART (Coustenis, A. et al. [2007]. Icarus 189, 35-62; Coustenis, A. et al. [2010]. Icarus 207, 461-476). From the analysis of nadir spectra we have derived a mixing ratio of 0.14±0.05ppb at an altitude of 97km, which corresponds to an integrated (from 0 to 600km) surface normalized column abundance of 3.7±1.3×10 14molecules/cm 2. In the latitude range 80°S to 30°N we see no evidence for latitudinal variations in these abundances within the error bars. Using limb observations, we obtained mixing ratios of 0.13±0.04ppb at an altitude of 115km and 0.45±0.15ppb at an altitude of 230km, confirming that the water abundance has a positive vertical gradient as predicted by photochemical models (e.g. Lara, L.M., Lellouch, F., Lopez-Moreno, J.J., Rodrigo, R. [1996]. J. Geophys. Res. 101(23), 261; Wilson, E.H., Atreya, S.K. [2004]. J. Geophys. Res. 109, E6; Hörst, S.M., Vuitton, V., Yelle, R.V. [2008]. J. Geophys. Res., 113, E10). We have also fitted our data using scaling factors of ~0.1-0.6 to these photochemical model profiles, indicating that the models over-predict the water abundance in Titan's lower stratosphere. © 2012 Elsevier Inc.. |
| Databáze: | OpenAIRE |
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