A 2-DIMENSIONAL MODEL OF PLASMA TRANSPORT AND CHEMISTRY IN THE JOVIANMAGNETOSPHERE

A two-dimensional model of plasma transport and chemistry in the Jovia n inner magnetosphere that enables us to calculate ion and electron de nsities and temperatures as well as their radiative emission propertie s is presented. As input data, the model uses (assumed) neutral densit ies, arbitrary initial ion densities, and ion and electron (both therm al and hot) temperatures given by the published empirical model derive d from Voyager data. Six thermal ion species, three hot ion species, a nd both thermal and hot electrons are included. The calculated ion par titioning is similar to the results of previous numerical models (rath er than the empirical model). The observed general increase in tempera ture of both the ions and electrons versus distance can be accounted f or by a distributed neutral source. Model electron temperature (and th us torus emission) was found to be less than expected. Of three propos ed mechanisms that might account for the observed electron heating, na mely, (1) an increase in the temperature of the thermal ions, resultin g in electron heating via Coulomb collisions, (2) hot ions, presumably of ring current origin, diffusing inward and heating the thermal elec trons, and (3) a flux of suprathermal electrons, alternative (2) is mo st strongly supported by our model.