Our objective was to develop an MHD model for the interaction between the Jovian magnetospheric plasma and the moons. Therefore, the goal was to modify the MHD code MPI-AMRVAC and implement a self-consistent calculation of the electron temperature and the electron density which is crucial for the modeling of the moons' aurora. We encountered numerical difficulties in the implementation of the electron temperature and were not able to finish the development of the MHD code during the project time. We performed successful simulations of Io's and Europa's plasma interaction with the code ZEUS-MP which was applied by the fellow for the moons' plasma interaction but does not account for the electron temperature. We performed a systematic parameter study of Io's plasma interaction with different upstream plasma conditions and models of Io's atmosphere and volcanic plumes in order to calculate the Poynting flux radiated away from Io and to compare the modeled variations of the Poynting flux with the variations of the emitted power of the southern auroral footprint (a set of auroral spots at Jupiter resulting from Io’s plasma interaction, see Figure 1c) (2)) derived from Juno-Ultraviolet Spectrograph (UVS) observations. With the investigation of the relation between Io’s plasma interaction and the emitted power of Io’s southern footprint at Jupiter with our MHD model, we achieved one main goal of the project and provided new findings about the properties of Io's atmosphere and how the variability of Io's atmosphere affects the Poynting flux radiated away from the moon.
Furthermore, we performed a series of simulations of Europa's plasma interaction with different models of Europa's atmosphere and atmospheric plumes (see Figure 1a) and compared the results with in-situ measurements from the Galileo spacecraft in order to derive constraints on Europa’s atmosphere. During the project we established a collaboration with H. Huybrighs, a research fellow from ESTEC-ESA, to work on the Energetic Particle Detector (EPD) data from Galileo spacecraft flybys. Therefore, he applied our MHD simulation results of Europa's plasma interaction with different atmospheres and plumes and performed further simulations of the flux of energetic protons using a Monte Carlo particle tracing method and analyzed the EPD data by comparing the data with his simulation results.
Exploitation and dissemination of the results were achieved by presentations on large international as well as small focused national conferences and meetings, and seminars in research institutions. The project was presented, e.g. at AGU fall meeting 2019 in San Francisco (USA), the MOP meeting 2019 in Sendai (Japan), or Svenska rymdforskares samarbetsgrupp (SRS) meeting 2019 in Göteborg (Sweden). The studies on Europa's and Io's plasma interaction led to two scientific papers published in peer-reviewed journals and two collaboration papers in preparation. The last half year of the project was strongly affected by the Covid-19 pandemic through a series of cancellations of meetings and workshops as well as official travel restrictions.
