Search Publications
Statistical validation of a solar wind propagation model from 1 to 10 AU
Hansen, Kenneth C.; Zieger, Bertalan
A one-dimensional (1-D) numerical magnetohydrodynamic (MHD) code is applied to propagate the solar wind from 1 AU through 10 AU, i.e., beyond the heliocentric distance of Saturn's orbit, in a non-rotating frame of reference. The time-varying boundary conditions at 1 AU are obtained from hourly solar wind data observed near the Earth. Although simi…
Saturn kilometric radiation: Average and statistical properties
Gurnett, D. A.; Kurth, W. S.; Cecconi, B. +3 more
Since Cassini entered Saturn's magnetosphere in July 2004, the auroral Saturnian kilometric radiation (SKR), which dominates the kronian radio spectrum, is observed quasi-continuously. Consecutive orbits of the spacecraft covered distances to Saturn down to 1.3 Saturn radii, all local times and, since December 2006, latitudes as high as 60°. On th…
Measuring suprathermal electron parameters in space plasmas: Implementation of the quasi-thermal noise spectroscopy with kappa distributions using in situ Ulysses/URAP radio measurements in the solar wind
Zouganelis, I.
We discuss the implementation of the quasi-thermal noise spectroscopy using kappa velocity distribution functions for the electrons. The quasi-thermal noise spectroscopy is a powerful tool for in situ space plasma diagnostics based on the analysis of the electrostatic field spectrum produced by the quasi-thermal fluctuations of electrons. The elec…
Cluster observations of energetic electrons and electromagnetic fields within a reconnecting thin current sheet in the Earth's magnetotail
Eastwood, J. P.; Daly, P. W.; André, M. +12 more
We study the acceleration of energetic electrons during magnetotail reconnection by using Cluster simultaneous measurements of three-dimensional electron distribution functions, electric and magnetic fields, and waves in a thin current sheet. We present observations of two consecutive current sheet crossings where the flux of electrons 35-127 keV …
Planetary period oscillations in Saturn's magnetosphere: Phase relation of equatorial magnetic field oscillations and Saturn kilometric radiation modulation
Dougherty, M. K.; Andrews, D. J.; Cowley, S. W. H. +3 more
We examine the planetary-period oscillations in Saturn's magnetic field observed by the Cassini spacecraft on 23 near-equatorial periapsis passes in the inner magnetosphere spanning October 2004 to July 2006. Overall, we find that the phase of the magnetic oscillations is well organized by the long-timescale modulation phase of Saturn kilometric r…
Evidence of an extended electron current sheet and its neighboring magnetic island during magnetotail reconnection
Khotyaintsev, Y.; Vaivads, A.; Runov, A. +9 more
We have identified a spatially extended electron current sheet (ECS) and its adjacent magnetic island during a magnetotail reconnection event with no appreciable guide field. This finding is based on data from the four Cluster spacecraft and is enabled by detailed maps of electron distribution functions and DC electric fields within the diffusion …
Evolution of Kelvin-Helmholtz activity on the dusk flank magnetopause
Farrugia, C. J.; Fazakerley, A. N.; Owen, C. J. +3 more
Our purpose is to characterize the evolution of the magnetopause Kelvin-Helmholtz (KH) wave activity with changes in thickness of the adjacent boundary layer, geomagnetic latitude and interplanetary magnetic field (IMF) orientation. As the IMF turns northward, wave activity may be generated at the dayside before propagating down the tail, where th…
Electron densities in the upper ionosphere of Mars from the excitation of electron plasma oscillations
Gurnett, D. A.; Morgan, D. D.; Modolo, R. +3 more
In addition to remote radio sounding of the ionosphere of Mars, the MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) instrument on the Mars Express spacecraft is also able to measure the in situ electron density from the excitation of local electron plasma oscillations. This paper presents an investigation of the electron densi…
Auroral evidence of a localized magnetic anomaly in Jupiter's northern hemisphere
Gustin, Jacques; Clarke, John T.; Connerney, John E. P. +5 more
We analyze more than 1000 HST/Advanced Camera for Survey images of the ultraviolet auroral emissions appearing in the northern hemisphere of Jupiter. The auroral footprints of Io, Europa, and Ganymede form individual footpaths, which are fitted with three reference contours. The satellite footprints provide a convenient mapping between the norther…
Evidence for reconnection at Saturn's magnetopause
Coates, A. J.; Dougherty, M. K.; Thomsen, M. F. +4 more
Observations of Saturn's magnetopause by the Cassini Plasma Spectrometer (CAPS) and magnetometer have revealed clear instances of magnetic reconnection signatures, two of which are described here. Both encounters occurred at the equator in the prenoon sector as Cassini was exiting the magnetosphere. Evidence of heating in the electrons and ions is…