New benzene absorption cross sections in the VUV, relevance for Titan’s upper atmosphere

Autor: Norbert Champion, Tommi Koskinen, Martin Schwell, Ivan Lehocki, Roger V. Yelle, Yves Bénilan, Nicolas Fray, Et-touhami Es-sebbar, Fernando J. Capalbo
Přispěvatelé: Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Université (SU), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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 de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, See manuscript and published article., École normale supérieure - Paris (ENS Paris), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Sorbonne Universités, École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP)
Jazyk: angličtina
Rok vydání: 2016
Předmět:
Materials science
[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
010504 meteorology & atmospheric sciences
[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Atmospheres: composition
Ultraviolet observations
Atmospheric sciences
medicine.disease_cause
01 natural sciences
Molecular physics
Atmosphere
symbols.namesake
chemistry.chemical_compound
0103 physical sciences
medicine
[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]
Atmosphere of Titan
Benzene
Spectroscopy
010303 astronomy & astrophysics
Spectrograph
0105 earth and related environmental sciences
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere
Astronomy and Astrophysics
Titan: atmosphere
chemistry
13. Climate action
Space and Planetary Science
symbols
Occultations
Thermosphere
Titan (rocket family)
Ultraviolet
Zdroj: Icarus
Icarus, 2016, 265, pp.95-109. ⟨10.1016/j.icarus.2015.10.006⟩
Icarus, Elsevier, 2016, 265, pp.95-109. ⟨10.1016/j.icarus.2015.10.006⟩
ISSN: 0019-1035
1090-2643
DOI: 10.1016/j.icarus.2015.10.006⟩
Popis: This is a pre-print (pre-peer review) manuscript. It is moderately different from the accepted manuscript and from the published article. Citation of published article: Fernando J. Capalbo, Yves Bénilan, Nicolas Fray, Martin Schwell, Norbert Champion, Et-touhami Es-sebbar, Tommi T. Koskinen, Ivan Lehocki, Roger V. Yelle. Icarus, vol. 265, p. 95 - 109. February 2016. doi: 10.1016/j.icarus.2015.10.006.; International audience; Benzene is an important molecule in Titan’s atmosphere because it is a potential link between the gas phase and the organic solid phase. We measured photoabsorption in the ultraviolet by benzene gas at temperatures covering the range from room temperature to 215 K. We derived benzene absorption cross sections and analyzed them in terms of the transitions observed. No significant variation with measurement temperature was observed. We discuss the implications of our measurements for the derivation of benzene abundance profiles in Titan’s thermosphere, by the Cassini/Ultraviolet Imaging Spectrograph (UVIS). The use of absorption cross sections at low temperature is recommended to avoid small systematic uncertainties in the profiles. We used our measurements, together with absorption cross sections from other molecules, to analyze four stellar occultations by Titan, measured by UVIS during flybys T21, T41, T41_II, and T53. We derived and compared benzene abundance profiles in Titan’s thermosphere between approximately 530 and 1000 km, for different dates and geographical locations. The comparisons of our benzene profiles with each other, and with profiles from models of the upper atmosphere, point to a complex behavior that is not explained by current photochemical models.
Databáze: OpenAIRE
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