Closed Fluxtubes and Dispersive Proton Conics at Jupiter's Polar Cap. Issue 9 (29th April 2022)

• Record Type: Journal Article
• Authors: Szalay, J. R.; Clark, G.; Livadiotis, G.; McComas, D. J.; Mitchell, D. G.; Rankin, J. S.; Sulaiman, A. H.; Allegrini, F.; Bagenal, F.; Ebert, R. W.; Gladstone, G. R.; Kurth, W. S.; Mauk, B. H.; Valek, P. W.; Wilson, R. J.; Bolton, S. J.
• Is Part Of: Geophysical research letters. Volume 49:Issue 9(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-29
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2022GL098741
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Two distinct proton populations are observed over Jupiter's southern polar cap: a ∼1 keV core population and ∼1–300 keV dispersive conic population at 6–7 RJ planetocentric distance. We find the 1 keV core protons are likely the seed population for the higher‐energy dispersive conics, which are accelerated from a distance of ∼3–5 RJ . Transient wave‐particle heating in a "pressure‐cooker" process is likely responsible for this proton acceleration. The plasma characteristics and composition during this period show Jupiter's polar‐most field lines can be topologically closed, with conjugate magnetic footpoints connected to both hemispheres. Finally, these observations demonstrate energetic protons can be accelerated into Jupiter's magnetotail via wave‐particle coupling. Plain Language Summary: Jupiter's interaction with its surrounding environment is complex and many open questions related to this interaction remain. The aurora and charged particle environment of Jupiter's polar‐most regions can help us understand this complex interaction. The Juno spacecraft in a polar orbit about Jupiter observed multiple ion populations near Jupiter's southern pole. From these observations, we find there is a process that pushes protons away from Jupiter at very high energies into the outer reaches of Jupiter's magnetosphere. We also find that during these observations, Jupiter's magnetic field lines are "closed" and connected Jupiter at both ends. This is opposed to the other planetary magnetospheres known to exhibit open magnetic topologies in their polar‐most regions. Key Points: Dispersive proton conics are observed connected to Jupiter's polar cap Inferring perpendicular heating, the source region for these events is within a jovicentric distance of ∼3–5 RJ Plasma composition and trapped protons indicate closed magnetic structures exists even at Jupiter's most polar regions