Modification of Titan's ion tail and the Kronian magnetosphere: Coupled magnetospheric simulations

Three-dimensional multifluid/multiscale modeling is used to study the coupled interaction between the Kronian magnetosphere and Titan's induced magnetosphere. The multifluid aspect of the model allows ions from the solar wind, Saturn's ionosphere, Enceladus torus, and Titan's ionosphere to be tracked separately. The multiscale aspect of the model allows simultaneous resolution of global and local processes down to 100 km near Titan. In the simulation, Titan is placed in the premidnight sector at 2100 Saturn local time. Two orientations of interplanetary magnetic field (IMF) are considered: parallel and antiparallel to Saturn's planetary field. During parallel IMF, plasma conditions near Titan are relatively stable and Titan's ion tail extends to 10 Saturn radii. The ion tail produces mass loading of the Kronian plasma disk and leads to a modification of the position of the plasma sheet. During antiparallel IMF, fingers of cold dense plasma from the inner magnetosphere propagate outward, driven by the centrifugal interchange instability. Titan's interaction with the fingers causes enhanced outflow as well as large changes in the orientation of Titan's ion tail. The plasma fingers are also disrupted by the interaction with Titan. In both IMF configurations, ions lost from Titan do not produce a complete ion torus. However, Titan's ion tail has global importance because it influences the inner boundary of the plasma sheet and has the potential to modify Kronian auroral processes when it is in this position in the Kronian magnetosphere.