A review of Titan’s atmospheric phenomena

• Published in: The Astronomy and Astrophysics Review
• Main Authors: Hirtzig, Mathieu, Tokano, Tetsuya, Rodriguez, Sébastien, Le Mouélic, Stéphane, Sotin, Christophe
• Other Authors: 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), Planetary Science Laboratory Ann Arbor (PSL), University of Michigan Ann Arbor, University of Michigan System-University of Michigan System, Institut für Geophysik und Meteorologie Köln (IGN), Universität zu Köln = University of Cologne, Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique de Nantes UMR 6112 (LPGN), Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2009
• Subjects: Titan; satellites; Near-infrared; Clouds; Imagery; spectroscopy; spectro-imagery; [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]; South pole
• Online Access: https://u-paris.hal.science/hal-03657699; https://u-paris.hal.science/hal-03657699/document; https://u-paris.hal.science/hal-03657699/file/AARv_review_clouds_inpress.pdf; https://doi.org/10.1007/s00159-009-0018-0

International audience Saturn's satellite Titan is a particularly interesting body in our solar system. It is the only satellite with a dense atmosphere, which is primarily made of nitrogen and methane. It harbours an intricate photochemistry, that populates the atmosphere with aerosols, but that should deplete irreversibly the methane. The observation that methane is not depleted led to the study of Titan's methane cycle, starting with its atmospheric part. The features that inhabit Titan's atmosphere can last for timescales varying from year to day. For instance, the reversal of the north-south asymmetry is linked to the 16-year seasonal cycle. Diurnal phenomena have also been observed, like a stratospheric haze enhancement or a possible tropospheric drizzle. Furthermore, clouds have been reported on Titan since 1993. From these first detections and up to now, with the recent inputs from the Cassini-Huygens mission, clouds have displayed a large range of shapes, altitudes, and natures, from the flocky tropospheric clouds at the south pole to the stratiform ones in the northern stratosphere. It is still difficult to compose a clear picture of the physical processes governing these phenomena, even M. Hirtzig (B) LATMOS, IPSL