Dissipation of Titan%26apos;s north polar cloud at northern spring equinox

作者：Le Mouelic Stephane^*; Rannou Pascal; Rodriguez Sebastien; Sotin Christophe; Griffith Caitlin A; Le Corre Lucille; Barnes Jason W; Brown Robert H; Baines Kevin H; Buratti Bonnie J; Clark Roger N; Nicholson Philip D; Tobie Gabriel

来源：Planetary and Space Science, 2012, 60(1): 86-92.

DOI：10.1016/j.pss.2011.04.006

• Titan
• Cloud
• Meteorology
• Cassini
• VIMS

Saturn%26apos;s Moon Titan has a thick atmosphere with a meteorological cycle. We report on the evolution of the giant cloud system covering its north pole using observations acquired by the Visual and Infrared Mapping Spectrometer onboard the Cassini spacecraft. A radiative transfer model in spherical geometry shows that the clouds are found at an altitude between 30 and 65 km. We also show that the polar cloud system vanished progressively as Titan approached equinox in August 2009, revealing at optical wavelengths the underlying sea known as Kraken Mare. This decrease of activity suggests that the north-polar downwelling has begun to shut off. Such a scenario is compared with the Titan global circulation model of Rannou et al. (2006), which predicts a decrease of cloud coverage in northern latitudes at the same period of time.

• 出版日期2012-1
• 单位中国地震局