IGPP Seminar Series

The Mystery of Rotational Signals in Saturn's Magnetosphere

by Krishan Khurana


Saturnís internal field is famously axisymmetric. Yet observations from in-situ instruments show that the magnetosphere is rife with rotational features. Using observations from the first three years of Cassiniís orbit, I show that the periodicities observed by plasma detectors come in two flavors, the in-phase and out-of-phase periodicities where field and plasma intensities are either positively or negatively correlated with each other. I will show that both of these features can be explained by postulating that Saturnís current sheet has developed a tilt. Next, I discuss a mechanism to generate this tilt from the non-uniform forcing by the solar wind on a longitudinally asymmetric magnetosphere. Finally, I discuss a heuristic model of synchronous regeneration of longitudinal asymmetry in Saturnís magnetosphere by a process which maintains and reinforces the existing azimuthal variations in the charged particle fluxes.
Tuesday, 06 November 2007
3853 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM