Modeling the Composition and Structure of Jupiters Northern Aurora based on Junos MWR Maps

As the Juno perijove has moved north, the MicroWave Radiometer (MWR) has begun producing maps of the northern hemisphere that display the spatial structure of the northern aurora. These maps show auroral features in MWR channel 1 (0.6 GHz) which correlate with the UltraViolet Spectrograph (UVS) images. Previously in Hodges et al. (2020), heightened electron densities were only considered to reside in the auroral arcs. However, these new maps show that the whole auroral region has lower emission than that expected from Jupiters adiabatic thermal atmosphere (Li et al. 2020). The reduced antenna temperatures suggest that there are high electron densities in the overall auroral region. The previous work has been expanded by assuming the auroral plasma has a neutral charge, with both electrons and ions having densities on the order of 107 particles cm-3. For the cold plasma approximation, the aurora is modeled to have multiple layers, which would allow the electron density to decrease from the 109 cm-3 estimate in Hodges et al. (2020). The study also considers a hot plasma approximation. The hot plasma model assumes that the medium is collisionless, magnetized, and has a Maxwellian electron velocity distribution. These new models provide insight into the vertical structure of the aurorae and the relationship between ions and electrons in that region.