Statistics of Titan's South Polar Tropospheric Clouds

We present the first long-term study of the behavior of the sporadically observed tropospheric clouds recently discovered near Titan's south pole. We find that one or more small individual cloud systems is present in the 70°-80° south region during every night of observation. These clouds acc...

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Bibliographic Details
Published in:The Astrophysical Journal
Main Authors: Bouchez, Antonin H., Brown, Michael E.
Format: Article in Journal/Newspaper
Language:unknown
Published: American Astronomical Society 2005
Subjects:
Online Access:https://doi.org/10.1086/427693
Description
Summary:We present the first long-term study of the behavior of the sporadically observed tropospheric clouds recently discovered near Titan's south pole. We find that one or more small individual cloud systems is present in the 70°-80° south region during every night of observation. These clouds account for 0.5%-1% of Titan's 2.0 μm flux, consistent with a global cloud cover fraction of 0.2%-0.6%. Clouds observed over multiple-night observing periods remained nearly fixed in brightness and position with respect to Titan's surface. The continual presence of south polar clouds is consistent with the hypothesis that surface heating during the long period of continuous polar sunlight at the time of Titan's southern summer solstice drives seasonal convection and cloud formation at the pole. © 2005 American Astronomical Society. Received 2004 October 13; accepted 2004 November 23; published 2004 December 3. We thank the many observers who took time out of their own programs to observe Titan. This research is supported by NSF planetary astronomy grant AST-0401559.We thank Henry Roe and Emily Schaller for interesting comments and conversations. Published - 1538-4357_618_1_L53.pdf