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.
Bibliographical noteFunding Information:
We thank the many JADE and Juno team members that made these observations possible, M. Imai for JRM09 integrations, and B. Bonfond for the Figure 1 Jupiter image. We acknowledge Juno's NASA contracts NNM06AA75C and 699041X.
© 2022. The Authors.
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