Upstream of Saturn and Titan

Abstract

The formation of Titan's induced magnetosphere is a unique and important example in the solar system of a plasma-moon interaction where the moon has a substantial atmosphere. The field and particle conditions upstream of Titan are important in controlling the interaction and also play a strong role in modulating the chemistry of the ionosphere. In this paper we review Titan's plasma interaction to identify important upstream parameters and review the physics of Saturn's magnetosphere near Titan's orbit to highlight how these upstream parameters may vary. We discuss the conditions upstream of Saturn in the solar wind and the conditions found in Saturn's magnetosheath. Statistical work on Titan's upstream magnetospheric fields and particles are discussed. Finally, various classification schemes are presented and combined into a single list of Cassini Titan encounter classes which is also used to highlight differences between these classification schemes.

The latitudinal structure of the nightside outer magnetosphere of Saturn as revealed by velocity moments of thermal ions

“…It is also suggested that the thickness of the plasma sheet varies with the beat period. These new results motivated Szego et al (2013) to modify the simple structural model of Arridge et al (2011a). In the new model the dual periodicities of the equatorial region are also taken into account.…”

“…In the Kronian magnetosphere many properties of the observed fields, particles and waves show periodic variations, associated with the planetary rotation (Arridge et al, 2011a;. The periodicity observed in Saturn kilometric radiation (SKR) is a good example of these periods (Gurnett et al, 2005).…”

“…Arridge et al (2011a) proposed a "simple structural model" to describe the shape and the flapping of the magnetodisk.…”

The Structure of Titan’s N2 and CH4 Coronae

“…The two flybys shown in the figure sample roughly the same nightside region of Titan's atmosphere over the northern hemisphere and separated by only one Titan day. This implies that the structure of Titan's corona may vary substantially over relatively short timescales, which is more likely caused by the highly variable plasma environment in the vicinity of Titan (e.g., Arridge et al 2011a).…”

“Water group” ion induced ionization and dissociation of major constituents of atmosphere of Titan

“…The plasma is quite rapid, reaching the velocity of 170 km s 1 near Titan [1]. A precipitation of O + ions with keV energies was found at Titan by the Cassini CAPS spectrometer [2].…”