Articles | Volume 25, issue 11
29 Nov 2007
 | 29 Nov 2007

On magnetospheric electron impact ionisation and dynamics in Titan's ram-side and polar ionosphere – a Cassini case study

K. Agren, J.-E. Wahlund, R. Modolo, D. Lummerzheim, M. Galand, I. Müller-Wodarg, P. Canu, W. S. Kurth, T. E. Cravens, R. V. Yelle, J. H. Waite Jr., A. J. Coates, G. R. Lewis, D. T. Young, C. Bertucci, and M. K. Dougherty

Abstract. We present data from the sixth Cassini flyby of Titan (T5), showing that the magnetosphere of Saturn strongly interacts with the moon's ionosphere and exo-ionosphere. A simple electron ionisation model provides a reasonable agreement with the altitude structure of the ionosphere. Furthermore, we suggest that the dense and cold exo-ionosphere (from the exobase at 1430 km and outward to several Titan radii from the surface) can be explained by magnetospheric forcing and other transport processes whereas exospheric ionisation by impacting low energy electrons seems to play a minor role.