Plasmoids in the Jovian Magnetotail: Statistical Survey of Ion Acceleration with Juno Observations

Jupiter's magnetosphere provides a unique natural laboratory to study processes of energy transport and transformation. Spatially confined structures such as plasmoids generate strong electric fields in the Jovian magnetotail and are responsible for ion acceleration to high energies. We focus on the effectiveness of ion energization and acceleration in plasmoids. Therefore, we present a statistical study of plasmoid structures in the predawn magnetotail, which were identified in the magnetometer data of the Juno spacecraft from 2016 to 2018 and documented by Vogt et al. (2020). For our study we additionally use the energetic particle observations from the Jupiter Energetic Particle Detector Instrument (JEDI) which discriminates between different ion species. We are particularly interested in the analysis of the acceleration and energization of oxygen, sulfur, helium and hydrogen ions in plasmoids and how these processes are affected by the event properties, such as the radial distance and the local time of the observed plasmoids inside the magnetotail, and the electromagnetic turbulence. We find significant heavy ion energization in plasmoids close to the current sheet center which is in line with the previous statistical results on acceleration in plasmoids based on Galileo observations conducted by Kronberg et al. (2019). The observed effectiveness of the energization is dependent on the position of Juno during the plasmoid event. Our results show no dependence between electromagnetic turbulence and non-adiabatic acceleration for heavy ions during plasmoids which is in opposition to the findings of Kronberg et al. (2019).