Abstract
Two new Juno-observed particle features of Jupiter's main aurora demonstrate substantial diversity of processes generating Jupiter's mysterious auroral emissions. It was previously speculated that sometimes-observed potential-driven aurora (up to 400 kV) can turn into broadband stochastic acceleration (dominating at Jupiter) by means of instability. Here direct evidence for such a process is revealed with a “mono-energetic” electron inverted-V rising in energy to 200 keV, transforming into a region of broadband acceleration with downward energy fluxes tripling to 3,000 mW/m2, and then transforming back into a mono-energetic structure ramping down from 200 keV. But a second feature of interest observed nearby is unlikely to have operated in the same way. Here a downward accelerated proton inverted-V, with inferred potentials to 300–400 kV, occurred simultaneously with downward accelerated broadband electrons with downward energy fluxes as high as any observed (~3,000 mW/m2). This latter feature has no known precedent with Earth auroral observations.
Original language | English (US) |
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Pages (from-to) | 1277-1285 |
Number of pages | 9 |
Journal | Geophysical Research Letters |
Volume | 45 |
Issue number | 3 |
DOIs | |
State | Published - Feb 16 2018 |
All Science Journal Classification (ASJC) codes
- Geophysics
- General Earth and Planetary Sciences
Keywords
- Juno
- Jupiter
- aurora
- energetic particles
- magnetosphere