Dissipation of Titan's south polar clouds

• Published in: Icarus
• Main Authors: Schaller, Emily L., Brown, Michael E., Roe, Henry G., Bouchez, Antonin H., Trujillo, Chadwick A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Elsevier 2006
• Subjects: Titan; Infrared observations; Atmospheres; dynamics; Meteorology; Canada; Gemini; South Pole; South pole
• Online Access: https://doi.org/10.1016/j.icarus.2006.05.025

Nearly all adaptive optics images of Titan taken between December 2001 and November 2004 showed tropospheric clouds located within 30° of the south pole. We report here on a dissipation of Titan's south polar clouds observed in twenty-nine Keck and Gemini images taken between December 2004 and April 2005. The near complete lack of south polar cloud activity during this time, and subsequent resurgence months later at generally higher latitudes, may be the beginning of seasonal change in Titan's weather. The ∼5 month decrease in cloud activity may also have been caused by methane rainout from a large cloud event in October 2004. Understanding the seasonal evolution of Titan's clouds, and of any precipitation associated with them, is essential for interpreting the geological observations of fluid flow features observed over a wide range of Titan latitudes with the Cassini/Huygens spacecraft. © 2006 Elsevier Inc. Received 22 January 2006; revised 12 May 2006. Available online 18 July 2006. We thank Robert West and an anonymous reviewer for helpful comments. E.L.S. is supported by an NASA Graduate Student Research Fellowship. H.G.R. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under Award AST-0401559. Additional support was provided by an NSF Grant to M.E.B. (AST-0307929). The W.M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The Gemini Observatory is operated by the Association of Universities for Research in Astronomy, under a cooperative agreement with the NSF on behalf of the Gemini partnership: the NSF, the Particle Physics and Astronomy Research Council (UK), the National Research Council (Canada), Comision Nacional de Investigacion Cientfficay Tecnologica (CONICYT) (Chile), the Autralian Research Council (Australia), Conselho Nacional de ...