Variability of Jupiter's Magnetospheric Current Sheet Associated with Time-Dependent Mass-Loading, Transport and Chemistry in the Io Plasma Porus

Abstract:

Jupiter’s magnetospheric current sheet is generated by stresses imposed by rapid planetary rotation and hot plasma in the plasma sheet. The current carried in this current sheet is known to be variable on time-scales of months but the origin of this variability is not well-understood. Volcanic activity on the moon Io is also known to be variable and feeds plasma into the plasma sheet via the Io plasma torus. In this paper we investigate how this variability in the plasma source affects the current sheet.

We solve the time-dependent equations for diffusive radial transport coupled with a neutral-plasma chemistry model, thus allowing for time-dependent plasma sources and the motion of radial structures produced by such time-dependence. These time-dependent solutions are coupled to a semi-empirical Euler potential magnetospheric model to calculate time-dependent magnetospheric currents. In this paper we review our understanding of the jovian magnetospheric current sheet, present our modelling methodology, and apply this to understand the observed time-variability in the current sheet.