Journal article
Cold and Hot Electron Populations Observed by Juno‐JADE in the Jovian Magnetodisc
Geophysical research letters, Vol.52(17), e2025GL118209
09/16/2025
DOI: 10.1029/2025GL118209
Abstract
Despite their importance to a variety of plasma processes in Jupiter's magnetosphere, properties of the thermal and suprathermal electrons have been sparsely reported in past literature. To address this gap, we used data from Juno's Jovian Auroral Distributions Experiment Electron sensors to survey electron properties in Jupiter's magnetodisc between M‐shells of M = 9–40 and magnetic latitudes less than 20° within years 2016–2023. We fit the electron measurements with a sum of two anisotropic kappa distributions and provide estimates of the electron density, temperature, anisotropy, and thermodynamic kappa for the cold and hot populations, separately. We find that the electron temperature increases non‐adiabatically with M‐shell and the cold electron temperature anisotropy is most extreme near M = 15. We also provide estimates of the ambient electron properties near the Galilean moons, which should be treated with caution considering the many caveats of the fitting process, which is often associated with large uncertainties.
Plain Language Summary
Electrons play a critical role in Jupiter's magnetosphere, where they produce and respond to different physical processes. We surveyed properties of the electrons measured in Jupiter's inner and middle magnetosphere using the unprecedented amount of data gathered by the Juno spacecraft in this region. We fit a model distribution to the Juno observations to better understand the electron environment. We found that the electron temperature increases non‐adiabatically with M‐shell and electron temperature anisotropy is most extreme near the transition from the inner to the middle magnetosphere. We also provide estimates of the electron densities and temperature near the icy moons, and caution that the fitting is often imperfect and associated with large uncertainties.
Key Points
Electron distributions in the Jovian magnetodisc are well fit with two anisotropic kappa‐distributions
Estimates of density, temperature, anisotropy, and kappa index for cold and hot electrons are provided
Electron temperature increases non‐adiabatically with M‐shell until M ∼ 20
Details
- Title: Subtitle
- Cold and Hot Electron Populations Observed by Juno‐JADE in the Jovian Magnetodisc
- Creators
- Y. Sarkango - University of MinnesotaJ. R. Szalay - Princeton UniversityA. R. Poppe - University of California, BerkeleyQ. Nénon - Institut de Recherche en Astrophysique et PlanétologieZ. Y. Liu - Institut de Recherche en Astrophysique et PlanétologieF. Allegrini - Southwest Research InstituteD. J. McComas - Princeton UniversityR. W. Ebert - The University of Texas at San AntonioP. Kollmann - Johns Hopkins University Applied Physics LaboratoryG. Livadiotis - Princeton UniversityL. Y. Khoo - Princeton UniversityN. André - Centre National de la Recherche ScientifiqueJ.‐Z. Wang - Laboratory for Atmospheric and Space PhysicsF. Bagenal - University of Colorado BoulderS. Schlegel - University of CologneJ. Saur - University of CologneW. S. Kurth - University of IowaA. H. Sulaiman - University of Minnesota
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.52(17), e2025GL118209
- DOI
- 10.1029/2025GL118209
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Publisher
- AMER GEOPHYSICAL UNION
- Number of pages
- 10
- Grant note
- National Aeronautics and Space Administration (80NSSC21K0823; 80NSSC23K0658)
- Language
- English
- Date published
- 09/16/2025
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984962642702771
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