Open AccessSources of rotational signals in Saturn's magnetosphere
Author(s) -
Khurana Krishan K.,
Mitchell Donald G.,
Arridge Christopher S.,
Dougherty Michele K.,
Russell Christopher T.,
Paranicas Chris,
Krupp Norbert,
Coates Andrew J.
Publication year - 2009
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2008ja013312
Subject(s) - magnetosphere , magnetosphere of saturn , saturn , physics , plasma sheet , ring current , rings of saturn , rotation period , current sheet , solar wind , longitude , geophysics , magnetosphere of jupiter , astronomy , magnetopause , magnetic field , planet , magnetohydrodynamics , latitude , stars , quantum mechanics
Saturn's internal magnetic field is exceptionally symmetric about its rotation axis. Yet local and remotely sensed observations of field and plasma in Saturn's magnetosphere display periodicities close to Saturn's rotation period. In this communication we provide evidence that Saturn's inner/middle magnetosphere contains semipermanent azimuthal anomalies in the ring current region in the fluxes of energetic charged particles, plasma density, magnetic field, and electrical current with a longitudinal wave number m = 1. We demonstrate that in the presence of these anomalies and a finite solar elevation angle, the solar wind lifts Saturn's magnetosphere asymmetrically in longitude, generating a tilt in the current sheet of Saturn. The current sheet tilt further produces periodicities in Saturn's middle and outer magnetosphere. The ubiquitous nature of the ring current region anomalies and their profound influence on the magnetospheric structure strongly suggest that the period of the Saturn kilometric radiation (SKR) wave power is controlled by them.