Mass release process in the Jovian magnetosphere: Statistics on particle burst parameters

Abstract

The Jovian magnetosphere undergoes periodic reconfiguration processes mainly driven by the fast planetary rotation and mass loading from the moon Io. These reconfiguration processes of the Jovian magnetosphere are associated with the release of plasmoids discernible as ion flow bursts associated with bipolar magnetic signatures. We investigate these plasma flows statistically using data from the Energetic Particles Detector and from the magnetometer on board Galileo. The plasma flows are observed in different magnetospheric regions: the current sheet center, the plasma sheet boundary layers, and the lobe. We show that the bulk velocity of all species is the same for most of the magnetic field bipolar signatures associated with these plasma flows. The average speed of the observed plasmoids in the plasma sheet associated with the ion flow bursts is between 350 and 500 km s−1, and the duration of the events is between 10 and 20 min. The associated plasmoid length is correspondingly ∼9 RJ. The plasmoids are moving approximately with Alfvénic speed. The convection electric field during the plasmoid release is about an order of magnitude higher than the ambient value of the Jovian convection electric field.