Search Publications
Magnetospheric configuration and dynamics of Saturn's magnetosphere: A global MHD simulation
Hansen, Kenneth C.; Gombosi, Tamas I.; Kivelson, Margaret G. +4 more
We investigate the solar wind interaction with Saturn's magnetosphere by using a global magnetohydrodynamic simulation driven by an idealized time-varying solar wind input that includes features of Corotating Interaction Regions typically seen at Saturn. Our model results indicate that the compressibility of Saturn's magnetosphere is intermediate …
Driving Saturn's magnetospheric periodicities from the upper atmosphere/ionosphere
Gombosi, Tamas I.; Kivelson, Margaret G.; Jia, Xianzhe
Saturn's magnetospheric structure and the intensity of radio frequency emissions from its immediate surroundings are modulated at close to the planet's rotation period. Analogous rotation-modulated variations at Jupiter are readily interpreted as effects of the non-axisymmetric intrinsic magnetic field. At Saturn, to the contrary, the high level o…
Planetary period oscillations in Saturn's magnetosphere: Evolution of magnetic oscillation properties from southern summer to post-equinox
Dougherty, M. K.; Lamy, L.; Andrews, D. J. +3 more
We investigate the evolution of the properties of planetary period magnetic field oscillations observed by the Cassini spacecraft in Saturn's magnetosphere over the interval from late 2004 to early 2011, spanning equinox in mid-2009. Oscillations within the inner quasi-dipolar region (L ≤ 12) consist of two components of close but distinct periods…
Charged nanograins in the Enceladus plume
Lewis, G. R.; Coates, A. J.; Thomsen, M. F. +12 more
There have been three Cassini encounters with the south-pole eruptive plume of Enceladus for which the Cassini Plasma Spectrometer (CAPS) had viewing in the spacecraft ram direction. In each case, CAPS detected a cold dense population of heavy charged particles having mass-to-charge (m/q) ratios up to the maximum detectable by CAPS (∼104
Driving Saturn's magnetospheric periodicities from the upper atmosphere/ionosphere: Magnetotail response to dual sources
Kivelson, Margaret G.; Jia, Xianzhe
Despite the high degree of axial symmetry of Saturn's internal magnetic field, rotation-associated periodicities are evident in Saturn's electromagnetic radiation, its magnetic perturbations and its particle populations. Although close to the mean rotation period of the cloud tops, the electromagnetic period drifts slightly over a time scale of ye…
Dual periodicities in planetary-period magnetic field oscillations in Saturn's tail
Coates, A. J.; Dougherty, M. K.; Jackman, C. M. +5 more
We examine magnetic field data from 10 apoapsis passes of the Cassini spacecraft during 2006 when the spacecraft explored the midnight and dawn sectors of Saturn's magnetotail to down-tail distances of ∼65 RS (Saturn radius, RS, is 60,268 km). Oscillations in the radial component of the field near the ∼11 hour planetary perio…
Saturn's inner magnetospheric convection pattern: Further evidence
Gurnett, D. A.; Thomsen, M. F.; Tokar, R. L. +7 more
Observations of the radial locations of satellite absorption microsignatures in energetic particle data at Saturn have suggested the existence of an average convection pattern, fixed in local time, that is superimposed on the dominant near-corotation of the inner magnetosphere. Such a pattern should have additional observational consequences, and …
Reconnection at the magnetopause of Saturn: Perspective from FTE occurrence and magnetosphere size
Lai, H. R.; Russell, C. T.; Wei, H. Y. +2 more
Flux transfer events observed at Mercury, Earth, and Jupiter are attributed to spatially and temporally limited events in which the magnetosheath and magnetospheric magnetic field become interconnected and magnetic flux is transported from the dayside to the lobes of the magnetotail. Examination of the Saturnian magnetopause at local times from 10…
Cassini observations of ion and electron beams at Saturn and their relationship to infrared auroral arcs
Coates, A. J.; Brown, R. H.; Baines, K. H. +14 more
We present Cassini Visual and Infrared Mapping Spectrometer observations of infrared auroral emissions from the noon sector of Saturn's ionosphere revealing multiple intense auroral arcs separated by dark regions poleward of the main oval. The arcs are interpreted as the ionospheric signatures of bursts of reconnection occurring at the dayside mag…
Kelvin-Helmholtz instability at Saturn's magnetopause: Cassini ion data analysis
Wilson, R. J.; Delamere, P. A.; Bagenal, F. +1 more
On 13 December 2004 Cassini, on approach to Saturn from the dawn flank, crossed the magnetopause multiple times. During these events the plasma spectrometer had a good field of view of both the magnetospheric and magnetosheath plasmas that often flow in nearly opposite directions (compared with more typical orientations that only allow one regime …