Plasma waves in Jupiter's high‐latitude regions: Observations from the Juno spacecraft

The Juno Waves instrument detected a new broadband plasma wave emission (~50 Hz to 40 kHz) on 27 August 2016 as the spacecraft passed over the low‐altitude polar regions of Jupiter. We investigated the characteristics of this emission and found similarities to whistler mode auroral hiss observed at Earth, including a funnel‐shaped frequency‐time feature. The electron cyclotron frequency is much higher than both the emission frequency and local plasma frequency, which is assumed to be ~20–40 kHz. The E/cBratio was about three near the start of the event and then decreased to one for the rest of the period. A correlation of the electric field spectral density with the flux of an upgoing 20 to 800 keV electron beam was found, with a correlation coefficient of 0.59. We conclude that the emission is propagating in the whistler mode and is driven by the energetic upgoing electron beam. A new broadband plasma wave emission between 50 Hz and 40 kHz was discovered from Juno Waves data in Jupiter's high‐latitude polar regionsThe plasma waves are assumed to be propagating in the whistler mode below 40 kHzSignificant correlation found between Waves data and an upgoing electron beam from JEDI, indicating that the beam is the source of the radiation