Three‐dimensional multifluid simulation of the plasma interaction at Titan

Abstract

Using a three‐dimensional multifluid simulation, we demonstrate the importance of ion gyroradius and heavy ion effects when characterizing Titan's plasma interaction with the Kronian magnetosphere. Ion gyroradius and heavy ion effects drastically change the mass loading and magnetic field draping at Titan. We find that the large ion gyroradius of picked up ionospheric species results in an extension of the ionosphere and therefore the mass loading and magnetic pileup region on the anti‐Saturn side of Titan. Also, the additional thermal pressure provided by heavy ion cyclotron motion near Titan causes boundary layer currents to form at higher altitudes. The Saturn‐facing side of Titan's ionosphere experiences both magnetic shielding from the incident plasma at lower altitudes and additional heating due to the acceleration of heavy ions in the ionosphere. Finally, we find that well‐confined heavy ion beams form on the anti‐Saturn side of Titan's magnetosphere and extend more than three Titan radii from Titan's main ion tail. The location of this ion beam is dependent on the Kronian field orientation, and we find that during the TA, TB, and T3 encounters, the bulk of the ion beam was located below Titan's equatorial plane. We also find that for a single set of incident conditions, good agreement with Cassini magnetometer data from the TA, TB, and T3 encounters is obtained with the ion loss rate similar to that measured by Cassini during the TA encounter.