HR: 08:15h
AN: P21D-02    [Abstracts]
TI: The Meridional and Vertical Structure of Titan's Atmosphere from Cassini Radio Occultations
AU: * Flasar, F M
EM: f.m.flasar@nasa.gov
AF: NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771, United States
AU: Schinder, P J
EM: paul.schinder@ssedmail.gsfc.nasa.gov
AF: Cornell University, Department of Astronomy, Ithaca, NY 14853, United States
AU: Marouf, E A
EM: emarouf@email.sjsu.edu
AF: San Jose State University, Department of Electrical Engineering, San Jose, CA 95192, United States
AU: French, R G
EM: rfrench@wellesley.edu
AF: Wellesley College, Department of Astronomy, Wellesley, MA 02841, United States
AU: McGhee, C A
EM: cmcghee@wellesley.edu
AF: Wellesley College, Department of Astronomy, Wellesley, MA 02841, United States
AU: Kliore, A J
EM: arvydas.j.kliore@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Rd, Pasadena, CA 91109, United States
AU: Rappaport, N J
EM: Nicole.J.Rappaport@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Rd, Pasadena, CA 91109, United States
AB: The four radio occultations during the Cassini prime mission have provided soundings in northern winter at eight mid- and high-latitude locations: 74 S, 69 S, 53 S, 34 S, 33 S, 31 S, 53 N, and 73 N. In the lower troposphere, the meridional contrast in temperature is muted, and temperatures in the lowest two kilometers differ by only 1.5 K, except for the northernmost sounding, which is colder by another ~1-1.5 K. Near 30 S, the lapse rates of the retrieved temperature profiles near the surface are nearly adiabatic, but at higher latitudes the profiles are more stably stratified in both hemispheres. At high northern latitudes the profiles exhibit stable inversions above the surface. We discuss the effect of the methane distribution on the retrieved temperatures and interpret the observed thermal structure in terms of the atmosphere's radiative response and surface-atmospheric exchange.
DE: 0350 Pressure, density, and temperature
DE: 6281 Titan
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting