- 1Aix-Marseille Université, CNRS, CNES, Institut Origines, LAM, Marseille, France (bilal.benmahi@lam.fr)
- 2Laboratory for Planetary and Atmospheric Physics, STAR Institute, University of Liège, Liège, Belgium
- 3The University of Edinburgh, School of GeoSciences, Edinburgh, UK
- 4Space Science and Engineering Division, Southwest Research Institute, San Antonio, TX, USA
- 5NASA Langley Research Center, Hampton, Va, USA
- 6Science Systems And Applications Inc., Hampton, Va, USA
- 7Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
- 8Univ. Grenoble Alpes, CSUG, 38000 Grenoble, France
- 9Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- 10Institute for Space Astrophysics and Planetology, National Institute for Astrophysics (INAF-IAPS), Roma, Italy
- 11Space Research Institute (IWF), Austrian Academy of Sciences (ÖAW) Schmiedlstraße 6, 8042 Graz, Austria
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 H₂. Our analysis considers two types of electron energy distributions: monoenergetic and a kappa distribution with κ = 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 κ parameter in auroral regions, we assessed its impact on the altitude distribution of emissions. Our sensitivity analysis indicates that κ 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.
How to cite: Benmahi, B., Bonfond, B., Benne, B., Hue, V., Grodent, D., Barthélemy, M., Sinclair, J. A., Moirano, A., Head, L. A., Gladstone, R., Gronoff, G., Sicorello, G., Simon-Wedlund, C., Giles, R., and Greathouse, T. K.: Reconstruction of the 3D Auroral Structure Using Juno/UVS Observations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3530, https://doi.org/10.5194/egusphere-egu25-3530, 2025.
