Field-aligned beams and reconnection in the jovian magnetotail

TL;DR

This paper investigates plasma release phenomena in Jupiter's magnetotail, demonstrating that magnetic reconnection plays a key role in these reconfiguration events through energetic particle measurements.

Contribution

It provides evidence linking reconnection processes to plasma dynamics and energetic particle behaviors in Jupiter's magnetotail, based on detailed particle measurements.

Findings

Electrons propagate along magnetic field lines in PSBL.

Counterstreaming electron beams observed in PSBLs.

Field-aligned ion beams associated with electron beams.

Abstract

The release of plasma in the jovian magnetotail is observed in the form of plasmoids, travelling compression regions, field-aligned particle beams and flux-rope like events. We demonstrate that electrons propagate along the magnetic field lines in the plasma sheet boundary layer (PSBL), while close to the current sheet center the electron distribution is isotropic. The evidences of the counterstreaming electron beams in the PSBLs are also presented. Most of the field-aligned energetic ion beams are associated with the field-aligned electron beams and about half of them have the bipolar fluctuation of the meridional magnetic field component. Moreover they often show a normal velocity dispersion for the different species which fits well in the scenario of particle propagation from a single source. All features above are observed during jovian reconfiguration events which are typically bonded with plasma flow reversals. From all these characteristics, which are based on energetic particle measurements, we believe that the reconfiguration processes in the jovian magnetotail are associated with reconnection.