HR: 16:30h
AN: P44A-03 INVITED     [Abstracts]
TI: Saturn Temperatures, Winds, and Composition from Cassini CIRS
AU: Flasar, F
EM: f.m.flasar@nasa.gov
AF: NASA/GSFC, Code 693, Greenbelt, MD 20771 United States
AU: * Conrath, B J
EM: barney.j.conrath@gsfc.nasa.gov
AF: Cornell University, Space Sciences Bldg, Ithaca, NY 14853 France
AU: Achterberg, R K
EM: richard.k.achterberg@gsfc.nasa.gov
AF: SSAI, 5900 Princess Garden Parkway, Suite 300, Lanham, MD 20706 United States
AU: Simon-Miller, A A
EM: lepasm@gsfc.nasa.gov
AF: NASA/GSFC, Code 693, Greenbelt, MD 20771 United States
AU: Jennings, D E
EM: donald.e.jennings@nasa.gov
AF: NASA/GSFC, Code 693, Greenbelt, MD 20771 United States
AU: Bjoraker, G L
EM: Gordon.L.Bjoraker@nasa.gov
AF: NASA/GSFC, Code 693, Greenbelt, MD 20771 United States
AU: Orton, G S
EM: Glenn.S.Orton@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Bezard, B
EM: Bruno.Bezard@obspm.fr
AF: LESIA, CNRS-FRE 246, Observatoire de Paris, 5 place Jules Janssen, Meudon, F-9192 France
AU: Irwin, P
EM: irwin@atm.ox.ac.uk
AF: University of Oxford, Atmospheric, Oceanic, and Planetary Physics, Clarendon Laboratory, Parks Rd, Oxford, OX1 3PU United Kingdom
AU: Gautier, D
EM: Daniel.Gautier@obspm.fr
AF: LESIA, CNRS-FRE 246, Observatoire de Paris, 5 place Jules Janssen, Meudon, F-9192 France
AB: We summarize CIRS observations of Saturn's southern hemisphere during the approach phase and early part of the Cassini tour. Stratospheric temperatures near 1 mbar increase from the equator to the south pole by 20 K. It is approximately three saturnian weeks after southern summer solstice, suggesting an efficient radiative response to insolation. At the tropopause (100 mbar), the equator-pole temperature contrast is more subdued, consistent with a larger radiative relaxation time. Zonal winds have been derived from the observed temperature field. The limited latitude resolution the early CIRS observations (8 degrees) precludes resolving the mid-latitude jets, but at low latitudes there is a large decrease (~140 m/s) of the zonal winds above the cloud tops to the upper stratosphere. The CIRS spectral range (7 micrometers - 1 mm) encompasses the signatures of a panoply of compounds, including hydrocarbons, oxygen compounds, phosphine, ammonia, and isotopes of carbon, nitrogen, and hydrogen. The extension of coverage to submillimeter wavelengths offers a unique capability not fully realized before. A brief preview of CIRS observations in the next few months of the Cassini tour will be presented.
DE: 5704 Atmospheres--composition and chemistry
DE: 5707 Atmospheres--structure and dynamics
SC: Planetary Sciences [P]
MN: 2004 AGU Fall Meeting