GLOBAL CONTEXT OF THE GALILEO-E6 OBSERVATIONS OF JUPITERS-WHITE-OVALS

Galileo Solid State Imaging (SSI) data taken during the E6 orbit on Fe bruary 19, 1997 offer a brief, high-resolution glimpse of Jupiter's Wh ite Ovals. These data can be used to infer relative cloud heights and systematic rotations over a small area of latitude and longitude (appr oximately 20 degrees by 30 degrees) around the White Owls. To fully un derstand the behavior of these cloud systems, however, a longer time s pan of global data is necessary. In this paper, we utilize ground-base d Voyager and Hubble Space Telescope data to interpret the Galileo ima ges. We find that the White Ovals' translation rates have slowed from 0.39 deg day(-1) during the Voyager era to 0.13 deg day(-1) in 1996 an d they, along with three smaller anticyclonic systems, have coalesced into a system of alternating cyclonic and anticyclonic systems that ha s not been observed before. The largest of the ovals, BC, is now imped ing the eastward motion of the system, causing more rapidly translatin g anticyclonic cells to catch the system and increase the westward ext ension of the equally spaced features. Rotational velocities for BC an d a small anticyclonic system at 42 degrees S have also been measured and peak at 120 m sec(-1) for both systems, comparable to the Mitchell et al. (J. Geophys. Res. 86, 8751-8757) measurements of BC and the Gr eat Red Spot (GRS) from Voyager data. The motion of individual feature s and of the whole system in the ambient wind flow is discussed. (C) 1 998 Academic Press.