JOVIAN SYSTEM DATA ANALYSIS PROGRAM PROPOSAL SUMMARY

We plan to exploit the extensive real time survey (RTS) field and particle data from Galileo supplemented by observations from previous Jupiter missions to study several key problems pertaining to the structure and dynamics of Jupiter's magnetosphere. In order to establish the relative roles of solar wind and the internal plasma processes in shaping the structure and dynamics of Jupiter's magnetosphere, we will establish a database of averaged field in the lobe regions and perform multivariate analysis on it to study local time effects in the field strength and orientation in the database. We will develop a quantitative model of the structure of Jupiter's current sheet to understand the relative influences of centrifugal force and the solar wind dynamic forcing in containing the plasma near the equatorial plane. Improved models of Jupiter's current sheet are also required for constructing the empirical models of the magnetospheric field. By using new and existing techniques, we will compute and establish a database of electric current density in Jupiter's magnetosphere. The database will then be used in quantitative studies outlined below. By computing Lorentz force from the calculated current density and observed magnetic field, we will perform studies of stress balance in Jupiter's magnetosphere to understand the relative importance of cold and hot plasma in generating currents in Jupiter's magnetosphere. We will use the new database of radial current density to understand how the angular momentum is transferred outwards in Jupiter's magnetosphere. Data from the middle and outer magnetosphere in G2 and G8 orbits clearly show semi-periodic reconfigurations of Jupiter's magnetosphere. We will analyze field, particle and plasma wave spectrometer data to ask if these events constitute magnetic substorms. We will perform stress balance studies to understand why the magnetosphere undergoes reconfigurations during certain periods. The new data products resulting from these studies will be made available to the community though a home page on the internet.