Variability of Titan's induced magnetotail: Cassini magnetometer observations

Abstract

We study the structure and variability of Titan's magnetotail by analyzing Cassini magnetic field observations from all tail crossings between 2005 and 2013. Titan's magnetotail is strongly affected by fluctuations in the ambient magnetospheric field conditions. Therefore, even Titan flybys with nearly identical trajectories may reveal a completely different location and strength of the perturbations in the moon's tail. Short-scale variations of the ambient magnetospheric field may cause a "fragmentation" of Titan's magnetic lobes, as also seen in Cassini Plasma Spectrometer ion data. By transforming the magnetic field perturbations detected during all available tail crossings to the Draping Coordinate System, we identified the following general characteristics of Titan's plasma interaction: (1) Perpendicular to the background magnetic field and the corotation direction, Titan's magnetotail is confined to a narrow region with a diameter of about 5 Titan radii. Thus, Titan's tail exhibits a rather "flat" structure reminiscent of a delta wing. (2) The plasma incident upon Titan does not possess a significant velocity component along the Saturn-Titan line. (3) The nonzero component of the background field along the corotation direction generates an asymmetry of Titan's magnetotail which clearly manifests in Cassini magnetometer data. Key Points Survey of Cassini magnetometer data from 20 crossings of Titan's magnetotail Titan's tail structure strongly affected by ambient magnetospheric variability Delta wing structure perpendicular to initial velocity and magnetic field plane ©2014. American Geophysical Union. All Rights Reserved.