title: Evidence for a polar ethane cloud on Titan.
abstract: Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal the presence of a vast tropospheric cloud on Titan at latitudes 51 degrees to 68 degrees north and all longitudes observed (10 degrees to 190 degrees west). The derived characteristics indicate that this cloud is composed of ethane and forms as a result of stratospheric subsidence and the particularly cool conditions near the moon's north pole. Preferential condensation of ethane, perhaps as ice, at Titan's poles during the winters may partially explain the lack of liquid ethane oceans on Titan's surface at middle and lower latitudes.
authors.affiliation: Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, 85721 USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Griffith
authors.forename: P
authors.initials: P
authors.lastname: Penteado
authors.forename: P
authors.initials: P
authors.lastname: Rannou
authors.forename: R
authors.initials: R
authors.lastname: Brown
authors.forename: V
authors.initials: V
authors.lastname: Boudon
authors.forename: K H
authors.initials: KH
authors.lastname: Baines
authors.forename: R
authors.initials: R
authors.lastname: Clark
authors.forename: P
authors.initials: P
authors.lastname: Drossart
authors.forename: B
authors.initials: B
authors.lastname: Buratti
authors.forename: P
authors.initials: P
authors.lastname: Nicholson
authors.forename: C P
authors.initials: CP
authors.lastname: McKay
authors.forename: A
authors.initials: A
authors.lastname: Coustenis
authors.forename: A
authors.initials: A
authors.lastname: Negrao
authors.forename: R
authors.initials: R
authors.lastname: Jaumann
mesh_terms: D001272:Atmosphere; D003080:Cold Temperature; D004980:Ethane; D005118:Extraterrestrial Environment; D005740:Gases; D007053:Ice; D008697:Methane; D010777:Photochemistry; D018539:Saturn; D018531:Spacecraft
chemical_list: D005740:Gases; D007053:Ice; D004980:Ethane; D008697:Methane