A PRELIMINARY STUDY OF MIT COUPLING AT JUPITER BASED ON JUNO OBSERVATIONS AND MODELLING TOOLS

The dynamics of the Jovian magnetosphere is controlled by the complex in- terplay of the planet’s fast rotation, its solar-wind interaction and its main plasma source at the Io torus. Juno observations have amply demonstrated that the Magnetosphere-Ionosphere-Thermosphere (MIT) coupling process- es and regimes which control this interplay are significantly different from their Earth and Saturn counterparts. At the ionospheric level, these MIT cou- pling processes can be characterized by a set of key parameters which in- clude ionospheric electrodynamic parameters (conductances, currents and electric fields), exchanges of particles along field lines and auroral emissions. Knowledge of these key parameters in turn makes it possible to estimate the net deposition/extraction of momentum and energy into/out of the Jovian upper atmosphere. We will present a method combining Juno multi-instru- ment data (MAG, JADE, JEDI, UVS, JIRAM and WAVES), adequate modelling tools (the TRANSPLANET ionospheric dynamics model and a simplified set of ionospheric current closure equations) and the AMDA data handling tools to provide preliminary estimates of these key parameters and their variation along the ionospheric footprint of Juno’s magnetic field line and across the auroral ovals for three of the first perijoves of the mission. We will discuss how this synergistic use of data and models can also contribute to provide a better determination of poorly known parameters such as the vertical struc- ture of the auroral and polar Jovian neutral atmosphere.