Regions of ECH occurrence in different planetary magnetospheres. Two distinct regions of ECH waves are present in Saturn and Jupiter. ECH waves are seen in the equatorial regions outside the high density plasmasphere / plasma torus and also at intermediate latitude in the magnetospheres, where plasma is confined in a thin disc near centrifugal equator.

Magnetic reconnection has been commonly reported between the solar wind IMF and the magnetic field of Earth and other planets. This article is the first report of a reconnection event in the tail region of Ganymede, the only known moon with an intrinsic magnetic field. We show strong evidence of Juno passing very close to an X-line at Ganymede's tail. We report the observation of distinctive electron Bernstein mode waves with unique characteristics particular to a reconnection site. We detect a clear reversal of a magnetic field component. Electron densities and pitch angle distributions also support the findings. Finally, from the time sequence of the observations by the different instruments on Juno, we reconstruct a likely trajectory of Juno around the reconnection site.

We present evidence of damping of equatorial noise due to Finite-Larmor-radius (FLR) effect in the inner Van Allen belt. Detail observation of the FLR phenomenon in the inner belt region has not been reported until now. Waves primarily damped by the FLR mechanism can influence the energy dependent proton density structure. We analyze a typical case recorded by the Van Allen probe that involves FLR damping of equatorial noise, which was propagating radially towards the Earth, at L-shell ~1.7. As a result of this damping, protons in the energy range of ~18 – 21 MeV at L-shell ~1.7 – 2 get energized. This kind of wave-particle interaction should be included in the future models of the inner Van Allen belt. This phenomenon may also account for the unknown proton loss mechanism reported in Selesnick and Albert (2019).

• Observations of wave damping due to finite Larmor radius effect in the inner belt region • Evidence of wave-particle interaction modifying the proton density profile at L~1.8

We investigate the rare events of sudden appearances of relativistic electrons (>700 keV), which are normally confined to the Van Allen belts, in the slot region. The frequency of occurrence of these events are on average 1-2 per year. To cope with the scarcity of events, in this study we examine 21 years of trapped relativistic electron fluxes available from the POES and MetOp Space Environment Monitor (SEM‐2). Our statistical analysis show that these events can occur even during moderate geomagnetic activity. Occurrence of these events correlates with high speed solar winds or ICMEs depending on the phase of the solar cycle. Most importantly, we show that ULF wave activity plays a significant role in causing these events and the events could be predicted in 75% of the cases.

We have observed ~30 Hz EMIC wave on September 8, 2017 at ~10:45 to 10:55 UT. This wave is a 2XH+ EMIC wave. This wave was generated by pitch angle anisotropy of protons with energies in the range of ~40eV - 450eV. This anisotropy is likely resulted from strong background Magnetosonic wave. The high frequency EMIC wave caused precipitation of low energy particles in the ionosphere.