Journal article
Jupiter's Low‐Altitude Auroral Zones: Fields, Particles, Plasma Waves, and Density Depletions
Journal of geophysical research. Space physics, Vol.127(8), e2022JA030334
08/2022
DOI: 10.1029/2022JA030334
Appears in UI Libraries Support Open Access
Abstract
The Juno spacecraft's polar orbits have enabled direct sampling of Jupiter's low‐altitude auroral field lines. While various data sets have identified unique features over Jupiter's main aurora, they are yet to be analyzed altogether to determine how they can be reconciled and fit into the bigger picture of Jupiter's auroral generation mechanisms. Jupiter's main aurora has been classified into distinct “zones”, based on repeatable signatures found in energetic electron and proton spectra. We combine fields, particles, and plasma wave data sets to analyze Zone‐I and Zone‐II, which are suggested to carry upward and downward field‐aligned currents, respectively. We find Zone‐I to have well‐defined boundaries across all data sets. H+ and/or H3+ cyclotron waves are commonly observed in Zone‐I in the presence of energetic upward H+ beams and downward energetic electron beams. Zone‐II, on the other hand, does not have a clear poleward boundary with the polar cap, and its signatures are more sporadic. Large‐amplitude solitary waves, which are reminiscent of those ubiquitous in Earth's downward current region, are a key feature of Zone‐II. Alfvénic fluctuations are most prominent in the diffuse aurora and are repeatedly found to diminish in Zone‐I and Zone‐II, likely due to dissipation, at higher altitudes, to energize auroral electrons. Finally, we identify significant electron density depletions, by up to 2 orders of magnitude, in Zone‐I, and discuss their important implications for the development of parallel potentials, Alfvénic dissipation, and radio wave generation.
Key Points
We discuss how the various fields, particles, and plasma wave phenomena of Jupiter's low‐altitude auroral zones are related
We confirm that Zone‐I and Zone‐II carry upward and downward field‐aligned currents, respectively
We identify large‐scale electron density depletions over the auroral zones and discuss the implications for auroral acceleration processes
Details
- Title: Subtitle
- Jupiter's Low‐Altitude Auroral Zones: Fields, Particles, Plasma Waves, and Density Depletions
- Creators
- A. H. Sulaiman - University of IowaB. H. Mauk - Johns Hopkins University Applied Physics LaboratoryJ. R. Szalay - Princeton UniversityF. Allegrini - Southwest Research InstituteG. Clark - Princeton UniversityG. R. Gladstone - Southwest Research InstituteS. Kotsiaros - Technical University of DenmarkW. S. Kurth - University of IowaF. Bagenal - Laboratory for Atmospheric and Space PhysicsB. Bonfond - Astrophysics Research InstituteJ. E. P. Connerney - Johns Hopkins University Applied Physics LaboratoryR. W. Ebert - Southwest Research InstituteS. S. Elliott - University of MinnesotaD. J. Gershman - Goddard Space Flight CenterG. B. Hospodarsky - University of IowaV. Hue - Southwest Research InstituteR. L. Lysak - University of MinnesotaA. Masters - Imperial College LondonO. Santolík - Charles UniversityJ. Saur - University of CologneS. J. Bolton - Southwest Research Institute
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.127(8), e2022JA030334
- DOI
- 10.1029/2022JA030334
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Publisher
- Wiley
- Number of pages
- 24
- Grant note
- Praemium Academiae Award (LTAUSA17070) National Aeronautics and Space Administration (699041X)
- Language
- English
- Date published
- 08/2022
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984323338602771
Metrics
12 Record Views