Radial and Local Time Variations in the Thickness of Jupiter's Magnetospheric Current Sheet

The magnetic field observations from the Galileo, Ulysses, Voyager 1 and 2, and Pioneer 10 and 11 spacecraft are analyzed to understand the structures and thickness of the Jovian magnetospheric current sheet. Using a new technique that can determine the motion of the spacecraft relative to the current sheet, we have built the first global map of the thickness of the Jovian magnetospheric current sheet. We show that the current sheet thickness in Jupiter's magnetosphere is not equal everywhere but changes systematically with both radial distance and local time. The extremely thin dawnside current sheet appears to be linked to the stresses imposed by the solar wind on the open magnetic flux housed in the lobes of the magnetosphere in that sector. We also show evidence of a mostly closed magnetosphere in the dusk sector. We show that the current sheet thickness asymmetries likely arise from a field and plasma convection system set up by the reconnection of the interplanetary magnetic field with that of Jupiter.

Automated summary

The structures and thickness of the Jovian magnetospheric current sheet are analyzed using magnetic field observations from various spacecraft. A new technique is used to determine the motion of the spacecraft relative to the current sheet and a global map of the current sheet thickness is created. The current sheet is found to be non-uniform and varies with radial distance and local time. The thin dawnside current sheet is likely related to the solar wind's impact on the magnetosphere, while the dusk sector shows evidence of a mostly closed magnetosphere. The asymmetries in current sheet thickness are believed to be a result of the reconnection of the interplanetary and Jupiter's magnetic fields.