Jovian System Data Analysis Program

Cover Page/Proposal Summary

ROSS-99    NRA 99-OSS-01

Date Due: 5/5/99

The plasma added to the magnetosphere at Io is accelerated at right angles to the magnetic field near the magnetic equator, scattered in pitch angle so that it moves along the magnetic field and transported across the magnetic field by convection and diffusion. These processes lead to the ultimate loss of the plasma from the system either into the loss cone and then into the atmosphere or into the magnetodisk, and after reconnection, into the tail by controlling the diffusion and transport taking place. We know that the requisite waves exist but we have not surveyed the waves sufficiently to know the average properties of the waves including their amplitude, handedness, ellipticity, direction of propagation and variation in local time, latitude and radius. Moreover, new GEM data will soon be obtained by Galileo in the last region of the magnetosphere not yet probed by Galileo, 8 to 10 RJ, and more data will be added inside 8 RJ to the one pass that presently exists. Understanding these waves is critical to understanding the distribution of mass in the jovian magnetosphere, both in radial distance and in latitude. The proposed effort provides a quantitative determination of the mechanisms controlling this distribution and the loss of jovian plasma. We also determine what anisotropies in the plasma distribution function are needed in order to make the waves grow. The proposal uses experienced personnel, existing and new GEM data, and existing software, and trains a graduate student Z. Yu, and compare these anisotropies to those expected and observed. Finally we will make preparations for a final conference and book on the Galileo mission. This effort will consist of identifying a site, a time, topics and potential speakers in conjunction with the project office. This proposal does not include support for the conference itself or the conference proceedings.