1. Seasonal evolution of C2N2, C3H4, and C4H2 abundances in Titan’s lower stratosphere
- Author
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Nicholas A Teanby, Sébastien Lebonnois, Sandrine Vinatier, Patrick G. J. Irwin, Melody Sylvestre, School of Earth Sciences [Bristol], University of Bristol [Bristol], Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, and École normale supérieure - Paris (ENS Paris)-École normale supérieure - Paris (ENS Paris)
- Subjects
North pole ,010504 meteorology & atmospheric sciences ,Atmospheric circulation ,Astrophysics ,Atmospheric sciences ,01 natural sciences ,C-4 ,law.invention ,Latitude ,symbols.namesake ,[SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology ,law ,0103 physical sciences ,data analysis [Methods] ,010303 astronomy & astrophysics ,Stratosphere ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Physics ,planets and satellites: atmospheres ,Astronomy and Astrophysics ,methods: data analysis ,13. Climate action ,Space and Planetary Science ,Volume mixing ratio ,symbols ,atmospheres [Planets and satellites] ,Atmospheric dynamics ,Titan (rocket family) ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
Aims. We study the seasonal evolution of Titan’s lower stratosphere (around 15 mbar) in order to better understand the atmospheric dynamics and chemistry in this part of the atmosphere. Methods. We analysed Cassini/CIRS far-IR observations from 2006 to 2016 in order to measure the seasonal variations of three photochemical by-products: C4H2, C3H4, and C2N2. Results. We show that the abundances of these three gases have evolved significantly at northern and southern high latitudes since 2006. We measure a sudden and steep increase of the volume mixing ratios of C4H2, C3H4, and C2N2 at the south pole from 2012 to 2013, whereas the abundances of these gases remained approximately constant at the north pole over the same period. At northern mid-latitudes, C2N2 and C4H2 abundances decrease after 2012 while C3H4 abundances stay constant. The comparison of these volume mixing ratio variations with the predictions of photochemical and dynamical models provides constraints on the seasonal evolution of atmospheric circulation and chemical processes at play.
- Published
- 2018
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