Magnetic field fluctuations in Jupiter's middle magnetosphere on auroral field lines

Jupiter has the most powerful aurora in the solar system, which is currently studied by NASA's Juno spacecraft. Observations above Jupiter's poles have shown that electrons accelerated toward Jupiter, which contribute to auroral emissions, are frequently accompanied by electrons accelerated in the opposite direction, deep into Jupiter's large magnetosphere. These energetic, bidirectional electrons often exhibit broadband energy distributions consistent with a stochastic particle acceleration mechanism. Alfvén waves, which are observed as magnetic field fluctuations, are being discussed to play an important role in the acceleration process. These waves are belived to be generated by the discontinuous radial plasma transport from Jupiter's plasma source Io to the outer magnetosphere.  We investigate magnetic field and plasma measurements in Jupiter's middle magnetosphere, where Alfvénic fluctuations have been observed, to analyze if a correlation between magnetic field fluctuations and plasma velocity fluctuations can be observed.