Search Publications
Flow of mass and energy in the magnetospheres of Jupiter and Saturn
Delamere, Peter A.; Bagenal, Fran
We present simple models of the plasma disks surrounding Jupiter and Saturn based on published measurements of plasma properties. We calculate radial profiles of the distribution of plasma mass, pressure, thermal energy density, kinetic energy density, and energy density of the suprathermal ion populations. We estimate the mass outflow rate as wel…
Dusty plasma in the vicinity of Enceladus
Gurnett, D. A.; Persoon, A. M.; Kurth, W. S. +7 more
We present in situ Cassini Radio Plasma Wave Science observations in the vicinity of Enceladus and in the E ring of Saturn that indicate the presence of dusty plasma. The four flybys of Enceladus in 2008 revealed the following cold plasma characteristics: (1) there is a large plasma density (both ions and electrons) within the Enceladus plume regi…
Periodic motion of Saturn's nightside plasma sheet
André, N.; Coates, A. J.; Russell, C. T. +9 more
Saturn's magnetosphere is replete with magnetospheric periodicities; magnetic fields, plasma parameters, energetic particle fluxes, and radio emissions have all been observed to vary at a period close to that of Saturn's assumed sidereal rotation rate. In particular, periodicities in Saturn's magnetotail can be interpreted in terms of periodic ver…
Bifurcations of the main auroral ring at Saturn: ionospheric signatures of consecutive reconnection events at the magnetopause
Milan, S. E.; Bonfond, B.; Gérard, J. -C. +4 more
This work reports for the first time on bifurcations of the main auroral ring at Saturn observed with the UVIS instrument onboard Cassini. The observation sequence starts with an intensification on the main oval, close to noon, which is possibly associated with dayside reconnection. Consecutive bifurcations appear with the onset of dayside reconne…
Cassini observations of plasmoid structure and dynamics: Implications for the role of magnetic reconnection in magnetospheric circulation at Saturn
Jackman, C. M.; Cowley, S. W. H.; Slavin, J. A.
We survey the Cassini magnetometer data during the deep tail orbits in 2006, and find 34 direct encounters with plasmoids. They occur as single, isolated events but also in groups of two or more plasmoids as is frequently observed at Earth. We show a case study example of three such plasmoids over three hours, where we estimate an upper limit of 5…
Titan's thermospheric response to various plasma environments
Luhmann, J. G.; Johnson, R. E.; Magee, B. A. +5 more
The Cassini-Huygens mission has been observing Titan since October 2004, resulting in over 70 targeted flybys. Titan's thermosphere is sampled by the Ion and Neutral Mass Spectrometer (INMS) during several of these flybys. The measured upper atmospheric density varies significantly from pass to pass. In order to quantify the processes controlling …
Influence of negatively charged plume grains on the structure of Enceladus' Alfvén wings: Hybrid simulations versus Cassini Magnetometer data
Dougherty, Michele K.; Saur, Joachim; Kriegel, Hendrik +5 more
We apply the hybrid simulation code AIKEF (adaptive ion kinetic electron fluid) to the interaction between Enceladus' plume and Saturn's magnetospheric plasma. For the first time, the influence of the electron-absorbing dust grains in the plume on the plasma structures and magnetic field perturbation, the Alfvén wing, is taken into account within …
Emission and propagation of Saturn kilometric radiation: Magnetoionic modes, beaming pattern, and polarization state
Schippers, P.; Gurnett, D. A.; Kurth, W. S. +7 more
The Cassini mission crossed the source region of the Saturn kilometric radiation (SKR) on 17 October 2008. On this occasion, the Radio and Plasma Wave Science (RPWS) experiment detected both local and distant radio sources, while plasma parameters were measured in situ by the magnetometer and the Cassini Plasma Spectrometer. A goniopolarimetric in…
Energetic particle phase space densities at Saturn: Cassini observations and interpretations
Krupp, N.; Jackman, C. M.; Roussos, E. +4 more
Saturn's magnetosphere has been studied extensively by the Cassini spacecraft during the last 6 years. We present mission-averaged energetic proton and electron measurements obtained by the MIMI/LEMMS instrument onboard Cassini in an energy range from several 10 keV to several 10 MeV separated by equatorial pitch angle. We discuss the resulting ra…
Influence of negatively charged plume grains and hemisphere coupling currents on the structure of Enceladus' Alfvén wings: Analytical modeling of Cassini magnetometer observations
Dougherty, Michele K.; Saur, Joachim; Kriegel, Hendrik +3 more
We present an analytical model of the Alfvén wing system that is generated by the interaction between the plume of Enceladus and the corotating plasma in Saturn's inner magnetosphere. Our primary purpose is to explain the orientation of the magnetic field perturbations detected in Enceladus' Alfvén wings by the Cassini magnetometer (MAG) instrumen…