Axially Asymmetric Steady State Model of Jupiter's
Magnetosphere-Ionosphere Coupling
Abstract
We present an axially asymmetric steady state model of Jupiter’s
magnetosphere-ionosphere coupling with variable ionospheric conductivity
dependent on the field-aligned current density. We use Juno and Galileo
data to construct a simple model of the equatorial magnetic field, and
develop a method for solving the system of partial differential
equations describing magnetosphere-ionosphere coupling. Using this model
we study the behavior of the system with different radial mass transport
rates of magnetospheric plasma and the effect of additional
field-aligned currents associated with Jupiter’s nightside partial ring
current. We compare the model magnetodisc current intensities with those
determined directly from magnetic field measurements in various local
time sectors, and find that the value of mass transport rate of 2000
kg/s, larger than usually estimated, better accounts for the observed
radial currents. We also find that the inclusion of field-aligned
currents associated with Jupiter’s partial ring current helps to explain
the local time variation of the radial currents, reducing the
discrepancy between the model and the observations.