Joint Cassini, Galileo and ground-based infrared observations of Jupiter's atmosphere

During the simultanous Galileo and Cassini encounter with Jupiter in December, 2000, and January, 2001, data on its atmosphere were obtained simultaneously by (1) Galileo's Photopolarimeter-Radiometer (PPR) at 27 microns, (2) Cassini's Composite Infrared Spectrometer (CIRS) between 7 and 16 microns, and (3) ground-based imaging from the NASA IRTF between 5 and 24 microns. These data sets mapped temperature structure, minor and trace constituent abundances and the NH>3 3< gas are associated with regions of substantial cloudiness. The meridional variability of zonally averaged para-H2 abundances is similar to that observed by Voyager IRIS at Jupiter; it is more abundant in the Great Red Spot than in surrouding regions. Implications of these and other observations will be discussed. This work was supported by NASA grants to JPL, GSFC and Cornell, as well as the Galileo and Cassini projects.