Jupiter’s magnetodisc and magnetospheric currents during Juno’s prime mission.

We study Jupiter’s magnetic field and plasma parameters during Juno’s prime mission, using data from Juno’s FGM magnetometer and ion measurements from the  Jovian Auroral Distributions Experiment Ion (JADE-I) sensor on Juno.  We compare the observed poloidal magnetic field and  plasma density, angular velocity and temperature profiles, with predictions from the Nichols et al. (2015)  axisymmetric magnetic vector potential model.  This  magnetodisc model balances the j x B force of the azimuthal magnetodisc currents with the outwards forces of the plasma pressure gradient, plasma pressure anisotropy and the centrifugal force associated with the rotating plasma.  By varying the model parameters for each orbit we model how Jupiter’s mass outflow rate, plasma angular velocity and ‘hot’ and ‘cold’ plasma temperatures and densities vary throughout Juno’s prime mission.  We further examine how changes in magnetospheric conditions are related to variations in the magnetosphere–ionosphere coupling parameters, in particular by studying the azimuthal and radial currents and the ionospheric field-aligned current density.