37th DPS Meeting, 4-9 September 2005
Session 30 Outer Planets
Poster, Tuesday, September 6, 2005, 6:00-7:15pm, Music Lecture Room 5

## [30.19] Saturn's atmospheric structure: the intercomparison of Cassini/CIRS-derived temperatures with ground-based determinations

P.D. Parrish, G.S. Orton, P.A. Yanamandra-Fisher (Jet Propulsion Laboratory), L. Fletcher, P.G.J. Irwin, N. Teanby (Oxford University), F.M. Flasar, C.A. Nixon, A.A. Simon-Miller (Goddard Space Flight Center), Cassini CIRS Team

\noindent Although Saturn is similar to that of Jupiter in several respects, it has yet to be qualitatively-determined whether Saturn experiences similar seasonal variation of its equatorial stratosphere as have been observed on Jupiter [Orton {\em et al.}, 1991; Flasar {\em et al.}, 2003] and Earth [Linzen, 1968; reviewed by Baldwin {\em et al.}, 2003]. While the nature of the radiatively-based, seasonal forcing on Jupiter is not fully understood, the modulated-temperatures are thought to play an important role in the transport of momentum between the troposphere and the stratosphere of any planet [Friedson, 1999]. The recent arrival of the Cassini-Huygens spacecraft to the Saturnian system provides an ideal opportunity to study this phenomena on Saturn. Specifically, what is the spatial orientation and temporal organisation of the atmospheric structure at upper-tropospheric/lower-stratospheric altitudes with regard to the dynamical models of other, better-characterised planets? The preliminary analysis, comparing Cassini Composite Infrared Spectrometer-derived temperatures with those obtained via images taken with NASA's Infrared Telescope Facility will be presented.

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Flasar, F.M. et al. (2003). Nature, 429(6969): 132-135.

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Lindzen, R.S. et al. (1968). J. Atmos. Sci., 25: 1095-1107.

Orton, G.S. et al. (1991). Science, 252: 537-542.

Acknowledgements: The acquisition of data described here was accomplished through the coordinated effort of Cassini-Huygens project staff, Deep Space Network personel and the CIRS instrument and science-planning teams with funding provided by NASA/JPL, the UK Particle Physics and Astronomy Council, NASA/GSFC and the National Research Council Research Associate Program.

Bulletin of the American Astronomical Society, 37 #3
© 2004. The American Astronomical Soceity.