Planetary Infrared Observations: The Occultation of 28 Sagittarii by Saturn and the Dynamics of Jupiter's Atmosphere.

The thesis consists of three parts. Part I reports an imaging observation of the occultation of 28 Sgr by Saturn and its rings, including a map of ring optical depth at 5-km resolution, ring event timings accurate to ~0.05 sec (~1 km in the ring plane), ring masses, and observation of material both in the deepest part of the B ring and exterior to the F ring. Part II reports imaging observations of Jupiter's tropospheric cloud opacities at a wavelength of 4.9 microns. Power spectrum analysis reveals an inertial enstrophy cascade between planetary wavenumbers ~25 and ~50. The power law exponent that best fits the cascade is -3.09 +/- 0.13, close to the theoretical value of -3. The power law indicates that there is no significant energy input in Jupiter's atmosphere in this wavenumber range, implying that baroclinic instability may not be important on Jupiter. The spectra show no slowly-moving planetary-scale waves. This is despite the detection by others of such features in images sensitive to the stratosphere. These data have ten times the spatial resolution and twice the temporal resolution of a prior null wave search at this wavelength. The question of how the thermal features are connected to the rotation rate of the interior remains open. Appendices describe new techniques for automated image mosaic assembly and planetary limb identification. Part III presents models of the impact of comet P/Shoemaker-Levy 9 on Jupiter that predict observable inertia-gravity waves resulting from the collisions. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617 -253-5668; Fax 617-253-1690.).