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Abstract The Juno mission, in conjunction with past missions and Earth‐based observations, has provided a wealth of information on Jupiter's magnetosphere. This magnetosphere is governed by Jupiter's strong magnetic field, rapid 10‐hr rotation, and a significant internal plasma source, the volcanic moon Io. Jupiter's magnetodisc exhibits plasma temperatures that deviate strongly from adiabatic expectations, increasing by nearly two orders of magnitude between the Io plasma torus and ∼25 . The physical mechanisms responsible for this heating remain poorly understood, particularly in the middle magnetosphere where advective transport dominates. In this study, we use a global magnetohydrodynamic (MHD) simulation to investigate the processes controlling plasma temperature evolution. Fluid tracing and test particle simulations are performed to analyze radial transport and energization within the magnetodisc. Our results reproduce key features of the observed temperature profiles, including the pronounced increase beyond 10 , without the need for additional heating terms. We demonstrate that a combination of tail reconnection, adiabatic compression, and large‐scale radial and corotational transport can explain the simulated temperature profiles, providing insight into the mechanisms governing plasma heating in Jupiter's magnetodisc. These findings highlight the importance of global scale MHD processes in shaping the thermal structure of the middle magnetosphere and offer a framework for interpreting Juno observations in regions not directly observed.
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The Role of Pedersen Conductance on the Dawn‐Dusk Asymmetries in Jupiter's Magnetosphere‐Ionosphere System: Model‐Data Comparisons
Abstract Jupiter's rapidly rotating magnetosphere, with internal plasma sources such as the volcanic moon Io, provides a unique natural laboratory for studying internally driven planetary magnetospheres. Using the Grid Agnostic Magnetohydrodynamics for Extended Research Applications (GAMERA) model, we simulated Jupiter's magnetosphere with variable ionospheric Pedersen conductances, which is mainly responsible for energy dissipation between the ionosphere and magnetosphere though convection. We chose values ranging from 0.5 to mho to investigate the Pedersen conductance's role in controlling mid‐magnetosphere region's dynamics and the closing of magnetosphere‐ionosphere currents. Simulated density, temperature, and radial and azimuthal flows in the equator are compared with observations from the Jovian Auroral Distributions Experiment (JADE) on the Juno spacecraft. All simulation cases exhibit dawn‐dusk asymmetries, in both the ionosphere and magnetosphere. The 0.5 case showed the best agreement with JADE observations, while the 1 case exhibited a magnetic topology more consistent with the auroral observations from the Hubble Space Telescope and Juno. These results enhance our understanding of Jupiter's magnetosphere‐ionosphere coupling, provide context for observations, and inform the background parameters of future test particle simulations and data‐model comparisons using the GAMERA model.
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- Award ID(s):
- 2350463
- PAR ID:
- 10708589
- Publisher / Repository:
- American Geophysical Union
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Space Physics
- Volume:
- 130
- Issue:
- 10
- ISSN:
- 2169-9380
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1029/2025JA034189
