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Radial and local time structure of the Saturnian ring current, revealed by Cassini
Krupp, N.; Dougherty, M. K.; Thomsen, M. F. +6 more
We analyze particle and magnetic field data obtained between July 2004 and December 2013 in the equatorial magnetosphere of Saturn, by the Cassini spacecraft. The radial and local time distribution of the total (thermal and suprathermal) particle pressure and total plasma beta (ratio of particle to magnetic pressure) over radial distances from 5 t…
Io plasma torus ion composition: Voyager, Galileo, and Cassini
Steffl, Andrew J.; Bagenal, Fran; Nerney, Edward G.
The Io torus produces ultraviolet emissions diagnostic of plasma conditions. We revisit data sets obtained by the Voyager 1, Galileo, and Cassini missions at Jupiter. With the latest version (8.0) of the CHIANTI atomic database we analyze UV spectra to determine ion composition. We compare ion composition obtained from observations from these thre…
Density Structures, Dynamics, and Seasonal and Solar Cycle Modulations of Saturn's Inner Plasma Disk
André, N.; Persoon, A. M.; Garnier, P. +7 more
We present statistical results from the Cassini Radio and Plasma Wave Science (RPWS) Langmuir probe measurements recorded during the time interval from orbit 3 (1 February 2005) to 237 (29 June 2016). A new and improved data analysis method to obtain ion density from the Cassini LP measurements is used to study the asymmetries and modulations foun…
Diamagnetic depression observations at Saturn's magnetospheric cusp by the Cassini spacecraft
Coates, Andrew J.; Krupp, Norbert; Arridge, Christopher S. +4 more
The magnetospheric cusp is a region where shocked solar wind plasma can enter a planetary magnetosphere, after magnetic reconnection has occurred at the dayside magnetopause or in the lobes. The dense plasma that enters the high-latitude magnetosphere creates diamagnetic effects whereby a depression is observed in the magnetic field. We present ob…
Dawn Auroral Breakup at Saturn Initiated by Auroral Arcs: UVIS/Cassini Beginning of Grand Finale Phase
Badman, S. V.; Bonfond, B.; Gérard, J. -C. +4 more
We present Cassini auroral observations obtained on 11 November 2016 with the Ultraviolet Imaging Spectrograph at the beginning of the F-ring orbits and the Grand Finale phase of the mission. The spacecraft made a close approach to Saturn's southern pole and offered a remarkable view of the dayside and nightside aurora. With this sequence we ident…
The role of plasma slowdown in the generation of Rhea's Alfvén wings
Dougherty, Michele K.; Russell, Christopher T.; Fatemi, Shahab +5 more
Alfvén wings are known to form when a conducting or mass-loading object slows down a flowing plasma in its vicinity. Alfvén wings are not expected to be generated when an inert moon such as Rhea interacts with Saturn's magnetosphere, where the plasma impacting the moon is absorbed and the magnetic flux passes unimpeded through the moon. However, i…
Whistler mode waves upstream of Saturn
Gurnett, D. A.; Dougherty, M. K.; Kurth, W. S. +3 more
Whistler mode waves are generated within and can propagate upstream of collisionless shocks. They are known to play a role in electron thermodynamics/acceleration and, under certain conditions, are markedly observed as wave trains preceding the shock ramp. In this paper, we take advantage of Cassini's presence at 10 AU to explore the importance of…
Energetic Electron Periodicities During the Cassini Grand Finale
Krupp, N.; Roussos, E.; Mitchell, D. G. +2 more
The Cassini F ring and Proximal orbits took the spacecraft closer to Saturn than any previous mission and allowed determination of energetic charged particles (E > 20 keV) in the inner magnetosphere of the planet. The periodicities of the energetic electrons show a remarkable consistency when analyzed using Lomb periodograms. From the beginning…
Energy-banded ions in Saturn's magnetosphere
Thomsen, M. F.; Jackman, C. M.; Kurth, W. S. +3 more
Using data from the Cassini Plasma Spectrometer ion mass spectrometer, we report the first observation of energy-banded ions at Saturn. Observed near midnight at relatively high magnetic latitudes, the banded ions are dominantly H+, and they occupy the range of energies typically associated with the thermal pickup distribution in the in…
Swept Forward Magnetic Field Variability in High-Latitude Regions of Saturn's Magnetosphere
Coates, A. J.; Dougherty, M. K.; Masters, A. +3 more
Swept forward field is the term given to configurations of magnetic field wherein the field lines deviate from the meridional planes of a planet in the direction of its rotation. Evidence is presented for swept-forward field configurations on Cassini orbits around Saturn from the first half of 2008. These orbits were selected on the basis of high …