Dynamics of the Saturnian inner magnetosphere: First inferences from the Cassini magnetometers about small‐scale plasma transport in the magnetosphere

Abstract

The Cassini magnetometers reveal a very dynamic plasmadisc within the inner Saturnian magnetosphere during the first three orbits of the Cassini orbital tour. This corotation‐dominated region is known to contain various neutral and plasma populations and Voyager spacecraft observations suggest important radial transport processes redistribute the locally created plasma out to the remote magnetospheric regions, by a mechanism yet to be identified. In this work we report on anomalous magnetic field signatures in the inner regions of the magnetosphere (inside of 8 Saturn radii) that may participate in the radial transport and that seem to be consistent with signatures of interchanging flux tubes. These unusual events are characterized by sharp boundaries and abrupt changes of the magnetic pressure, consisting of depressions or enhancements of the field magnitude. They present some similarities with previously identified signatures of interchanging flux tubes in the Io torus, allowing the interesting possibility of carrying out a comparative study of these two environments.