IGPP Seminar Series

The Role of Methane in Titan's Clouds, Climate and Spin

by Jonathan Mitchell, Sponsored by the Geoscience Initiative
School of Natural Sciences Institute for Advanced Study Princeton

Abstract

Titan's atmosphere is laden with methane vapor, the equivalent of a 5 meter global ocean. Methane is near its triple point at Titans surface conditions, suggesting it should be thermodynamically active. I will demonstrate how the coupling of methane thermodynamics to Titans large-scale circulation limits cloud coverage and duration, defines climate zones, and damps the seasonal cycle. Cassini and ground-based observations are beginning to reveal these effects in the seasonality of methane clouds, the latitudinal distribution of surface morphologies, and a phase lag in Titans seasonal spin rate change, respectively. Several mysteries deserve further investigation including mechanisms sustaining the observed pattern of zonal winds and the long-term evolution of the methane reservoir. I will briefly discuss plans to extend this work to extrasolar planets
Wednesday, 21 May 2008
3853 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM