Vertical Current Density Structure of Saturn's Equatorial Current Sheet

Abstract

Routine spacecraft encounters with the Saturn current sheet due to the passage of aperiodic waves provide the opportunity to analyze the current sheet structure. The current density is expected to peak where the field strength reaches a minimum if approximated as a Harris current sheet. However, in Earth's magnetotail this is not always the case as the sheet is sometimes bifurcated (having two or more maxima in the current density). We utilize measurements of Saturn's magnetic field to estimate the current density during crossings of the current sheet by time differentiating the Ba component of the field in a current sheet coordinate system, where Ba is perpendicular to both the current and current sheet normal. This is then averaged and organized by the magnitude of Ba. Using this method, we can identify a classical Harris‐style or bifurcated current sheet as a peak at the center or two distinct maxima on either side of Ba=0, respectively. We find that around 10% of current sheet profiles exhibit a bifurcated current sheet signature, which is substantially lower than an ∼25% occurrence rate at Earth.