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Abstract :
[en] Jovian auroras, the most intense in the Solar System, arise from interactions between Jupiter's magnetosphere and atmosphere. While their horizontal morphology has been extensively studied, their vertical structure, shaped by the penetration depth of magnetospheric electrons, remains less well understood. Previous observations, including those from the Hubble Space Telescope (HST), have provided only partial insights into this aspect. This study aims to characterize the vertical structure of Jovian auroral emissions.We analyzed observations from Juno's UltraViolet Spectrograph (UVS) to examine the altitude and horizontal distribution of auroral emissions. Building on recent studies that mapped the average energy of precipitating electrons in auroral regions, we explored the relationship between this energy and the volume emission rate (VER) of H_2;. Our analysis considers two types of electron energy distributions: monoenergetic and a kappa distribution with kappa = 2.5.By leveraging brightness maps, we reconstructed the three-dimensional VER structure of Jovian auroras in both hemispheres across multiple spacecraft perijoves (PJs). For PJ11, we found that in the polar emission region, the average altitude of the VER peak is approximately 250 km for the monoenergetic case and 190 km for the kappa distribution. In the main emission region, the average altitude is around 260 km for the monoenergetic case and 197 km for the kappa distribution. Similar results were obtained for other PJs.Our findings align, on average, with measurements from the Galileo probe and HST observations, reinforcing the value of Juno data in probing the vertical structure of auroral emissions. Given the variability of the kappa parameter in auroral regions, we assessed its impact on the altitude distribution of emissions. Our sensitivity analysis indicates that kappa variability has a minor effect on the peak altitude of the VER but does influence the amplitude, suggesting potential effects on the thermal structure and chemical composition of Jupiter's auroral regions.
