Current Density in Saturn's Equatorial Current Sheet: Cassini Magnetometer Observations. Issue 1 (25th January 2019)

• Record Type: Journal Article
• Authors: Martin, C. J.; Arridge, C. S.
• Is Part Of: Journal of geophysical research. Volume 124:Issue 1(2019)
• Page Start: 279
• Page End: 292
• Publication Date: 2019-01-25
• Subjects: Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2018JA025970
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: The equatorial current sheet at Saturn is the result of a rapidly rotating magnetosphere. The sheet itself exhibits periodic seasonal and diurnal movements as well as aperiodic movements of a currently unknown origin, along with periodic thickening and thinning of the magnetodisc, and azimuthal changes in the thickness due to local effects in the magnetosphere. In this paper aperiodic movements of the magnetodisc are utilized to calculate the height‐integrated current density of the current sheet using a Harris current sheet model deformed by a Gaussian wave function. We find a local time asymmetry in both the radial and azimuthal height‐integrated current density. We note that the local time relationship with height‐integrated current density is similar to the relationship seen at Jupiter, where a peak of ∼0.04 A/m at ∼3 SLT (Saturn local time) is seen inside 20 R S . The divergence of the radial and azimuthal current densities are used to infer the parallel currents, which are seen to diverge from the equator in the prenoon sector and enter the equator in the premidnight sector. Key Points: Current density is estimated using a deformed Harris current sheet model Current density generally decreases with radial distance with some local time asymmetries mainly in the azimuthal current Divergence of the perpendicular current density used to infer parallel field‐aligned currents that can enhance auroral emission premidnight