Centrifugal Equator in Jupiter’s Plasma Sheet

Abstract

In Jupiter’s magnetosphere, the structure of the plasma sheet depends on the magnetic field geometry and the centrifugal forces on the plasma. We present a simple formulation for the centrifugal equator, the farthest point along a magnetic flux tube from the planetary spin axis, for Jupiter’s torus to plasma sheet region (5–30 jovian radii). The formulation is based on a dipole magnetic field and azimuthally symmetric current sheet, both tilted by 9.5° toward System III west longitude of 201°. We find a good fit to such a model with a hyperbolic tangent function varying sinusoidally with longitude. The latitudinal angle of the derived centrifugal equator relative to the jovigraphic equator changes from the dipolar value (2/3 of the dipole tilt) around 5 jovian radii to close to the full dipole tilt at 25 jovian radii.