The Jovian magnetodisk plays an essential role in the dynamics of the Jupiter system by coupling its various components. Here, we investigate the Juno (JADE, JEDI and MAG) observations of the magnetodisk within 20-80 Jupiter radii (RJ) in the 0-6 hour local time sector. JADE and JEDI data are combined to generate equatorial plane distributions of density, pressure, temperature, and anisotropy of electrons, protons, and heavy ions. Results show: (1) Heavy ions dominate both the number density and pressure. (2) The number density and pressure of all species decrease with radial distance. (3) The temperature increases for electrons and heavy ions and decreases for protons as radial distance increases. (4) On average, the parallel pressure exceeds the perpendicular pressure for all species. Based on these distributions, we explore the equilibrium and dynamics of the magnetodisk and show that: (1) Radial force balance is primarily achieved between the inward magnetic stress and the outward plasma anisotropy force. (2) An examination of the kappa parameters indicates that electrons, protons, and heavy ions primarily undergo adiabatic motion, magnetic moment diffusion, and stochastic motion, respectively. (3) A radial diffusion coefficient is derived from the radial profile of mass, providing an estimate of the timescale for radial transport from 20 to 80 RJ of  7 hours. (4) The total mass (\(5\times10^7\) kg) and thermal energy(\(3.8\times10^{37}\) eV) of the magnetodisk between 20 and 80 RJ are obtained.

On June 7th, 2021 the Juno spacecraft visited Ganymede and provided the first in situ observations since Galileo’s last flyby in 2000. The measurements obtained along a one-dimensional trajectory can be brought into global context with the help of three-dimensional magnetospheric models. Here we apply the magnetohydrodynamic model of Duling et al. (2014) to conditions during the Juno flyby. In addition to the global distribution of plasma variables we provide mapping of Juno’s position along magnetic field lines, Juno’s distance from closed field lines and detailed information about the magnetic field’s topology. We find that Juno did not enter the closed field line region and that the boundary between open and closed field lines on the surface matches the poleward edges of the observed auroral ovals. To estimate the sensitivity of the model results, we carry out a parameter study with different upstream plasma conditions and other model parameters.

Observations of energetic charged particles associated with Io’s footprint (IFP) tail, and likely within or very near the Main Alfvén Wing, during Juno’s 12th perijove (PJ) crossing show evidence of intense proton acceleration by wave-particle heating. Measurements made by Juno/JEDI reveal proton characteristics that include pitch angle distributions concentrated along the upward loss cone, broad energy distributions that span ~50 keV to 1 MeV, highly structured temporal/spatial variations in the particle intensities, and energy fluxes as high as ~100 mW/m2. Simultaneous measurements of the plasma waves and magnetic field suggest the presence of ion cyclotron waves and transverse Alfvénic fluctuations. We interpret the proton observations as upgoing conics likely accelerated via resonant interactions with ion cyclotron waves. These observations represent the first measurements of ion conics associated with moon-magnetosphere interactions, suggesting energetic ion acceleration plays a more important role in the IFP tail region than previously considered.