Energetic charged particle kinematics in Saturn's inner magnetosphere von Maria Andriopoulou | ISBN 9783942171779

Energetic charged particle kinematics in Saturn's inner magnetosphere

von Maria Andriopoulou
Buchcover Energetic charged particle kinematics in Saturn's inner magnetosphere | Maria Andriopoulou | EAN 9783942171779 | ISBN 3-942171-77-5 | ISBN 978-3-942171-77-9

Energetic charged particle kinematics in Saturn's inner magnetosphere

von Maria Andriopoulou
Plasma circulation in the Saturnian magnetosphere, and especially in its inner part, was a topic not fully understood prior to this thesis. The arrival of Cassini in the Saturnian system confirmed that the Saturnian magnetospheric plasma is mainly rotationally driven and this dominance initially prevented from resolving possible convection patterns through the usage of direct velocity measurements that were obtained from Cassini. In this thesis, I have developed a new method to resolve possibly existing convection patterns in the inner Saturnian magnetosphere. This method considers the effects that the icy moons have on energetic electrons, also known as energetic electron microsignatures. Particularly, it studies the radial displacement of the resulting dropouts from their predicted location. The latter can be estimated if one ignores any possible effects of non-corotation convection patterns. The development of this method led to the detection of a convective pattern that is related to dawnward flows of a few km/s in the inner magnetosphere of Saturn. The results of this method were later supported by other independent studies. In addition to this, plasma radial velocities measurements as well as global simulations also confirmed the proposed pattern. A big advantage of this method is that the observed offset is representative of the radial flows over all the local times that the microsignature has crossed before its detection, allowing for properties of the global circulation pattern to be inferred from single events. The continuously growing microsignature dataset is probably the best tool to derive additional properties of this electric field in order for its currently unknown origin to be revealed. This method to infer convection patterns can also be applied in the magnetospheres of other outer planets and be useful for future planetary missions.