On the flowside plasma environment of Titan

SZEGO, K.; BERTUCCI, C.; COATES, A. J.; BEBESI, Z.; ERDOS, G.; FOLDY, L.; YOUNG, D. T.; CRARY, F.; SITTLER, E. C.; HARTLE, R.; THOMSEN, M.

Congreso; AGU Fall Meeting 2006; 2006

We call the hemisphere of Titan centered on the corotation flow "the flowside hemisphere", and the perturbed plasma region surrounding the flowside ionosphere "the flowside plasma sphere" of Titan. Cassini explored this region three times between 18 March - 21 July, 2006; twice flying near the equatorial plane of Titan (T12 and T14), and once on a polar orbit (T16). These flowside flybys are not very favorable for low energy charged particle observations because the pointing of the spacecraft prefers remote sensing observations, and the corotating ions are outside the Cassini Plasma Spectrometer (CAPS). Despite this limitation, the combined study of the electron, ion, and magnetic field data has given new insights into the flowside plasma sphere. During these flybys the magnetic field was not in a dipole configuration. The perturbed plasma region both inbound and outbound extended to 6-7 R-Titan; its structure was not symmetric to the corotation direction. The different major regions of the plasma sphere were reflected simultaneously in the data we examined. Here we concentrate on the deceleration region, pointing out that the deceleration of the heavy and light ion components were different, leading to different bulk speeds of the species. Hence the plasma interaction is dominantly kinetic in this region.