Student seminar: Dynamics in Titan's ionosphere

The ionosphere of Titan was probed 127 times by Cassini-Huygens with its close encounters of the moon, and the plasma parameters of the surrounding ionospheric electrons and ions could be measured. Though the structure and dynamics of Titan’s ionosphere have been investigated extensively both with simulations and in situ measurements, there are still unexplained structures found in the topside ionosphere, which we want to understand. For instance, so-called ‘density spikes’ have been observed as a sharp increase of electron density, measured by the Langmuir probe (RPWS/LP) instrument, at an average altitude of ~1700 km above Titan’s surface. The preliminary results of the data analysis of RPWS/LP observation of density spikes for 28 cases are presented and discussed. We are focusing on describing the main features of observed structures and their origin. The supplement analysis of magnetic field data shows a coincident decrease of the magnetic field strength and a rotation of the field direction with the density spikes. We propose that the underlying process, which leads to the formation of these ionospheric structures and which we interpret as current sheets, is related to the interaction with Saturn’s magnetosphere.