Jovian System Data Analysis Program

Cover Page/Proposal Summary

ROSS-99    NRA 99-OSS-01

Date Due: 5/5/99

Several project utilizing the field and particle data from Galileo's GEM mission supplemented by observations from previous missions are proposed to establish the role of solar wind driven convection in Jupiter's magnetosphere. We will assemble a database of averaged field in the lobe regions and perform multivariate analysis on it to infer local time effects on the field of Jupiter's magnetosphere. We will compute electric current density in the equatorial plane of Jupiter's magnetosphere to infer the presence of a partial ring current on the nightside. We will use the current continuity equation to calculate the strength of field-aligned currents from the divergence of currents in the equatorial plane. Specifically, we will look for Region-2 sense currents that mark the presence of a solar wind driven convection system deep in a magnetosphere. We will use the results of the multivariate analysis on currents to understand why the Jovian aurora is consistently seen at lower latitudes on the nightside than it is seen on the dayside. We will analyze field and particle data to see if reconnection occurs in the dusk sector of the magnetotail. If local time asymmetries are found in the reconnection rate between the dawn and the dusk sectors of the magnetotail, we will perform stress balance analysis to understand why such a difference exists. We will make data products resulting from this study available to the community though a web page on the Internet.