Energetic electron microsignatures as tracers of radial flows and dynamics in Saturn's innermost magnetosphere
Coates, A. J.; Krupp, N.; Roussos, E.; Krimigis, S. M.; Mitchell, D. G.; Paranicas, C. P.; Bebesi, Z.; Kollmann, P.; Müller, A. L.
Germany, United States, Greece, United Kingdom
Abstract
Signatures of energetic electron depletions from Saturn's inner moons (microsignatures) have been mainly utilized to infer properties of magnetospheric diffusion. The same data, however, indicate that microsignatures can be a much more powerful tool for magnetospheric studies. Here we introduce a new method where the energy structure of a microsignature can be used to trace the location, the formation date, the evolution, and the physical properties of dynamic events in the inner Saturnian magnetosphere. Application to a complex electron microsignature of Tethys, seen by Cassini's MIMI/LEMMS and CAPS/ELS detectors, reveals the location and the age of such an event. The development stages of this event, that can also be distinguished, indicate the presence of local, pulse-like azimuthal electric field variations that can locally enhance radial transport by a factor of 1000-3000 with respect to radial diffusion. We also extract several physical properties of this dynamical region and speculate about its possible nature.