Search Publications
Direct evidence of differences in magnetic rotation rate between Saturn's northern and southern polar regions
Southwood, David
The discovery of a difference in apparent rotation rate between Saturn kilometric radio emission from northern and southern hemispheres leads immediately to the question of whether there is a counterpart detectable in the Saturnian magnetic field. We report direct detection of a difference in the rotating magnetic signal measured by the Cassini sp…
Pitch angle evolutions of oxygen ions driven by storm time ULF poloidal standing waves
Zong, Q. -G.; Reme, H.; Fu, S. Y. +9 more
We present the first systematic observational study on the pitch angle evolutions of O+ ions associated with ULF Pc5 poloidal standing waves excited during geomagnetic storms. The O+ ion measurements are made on board the CLUSTER satellites with the Composition Distribution Function (CODIF) instrument, which covers energies f…
Transient Pc3 wave activity generated by a hot flow anomaly: Cluster, Rosetta, and ground-based observations
Glassmeier, K. -H.; Eastwood, J. P.; Wild, J. A. +6 more
Pc3 pulsations are observed in the magnetosphere with wave periods of 10-45 s. Two distinct populations have been observed; one exhibits a frequency dependence on the solar wind magnetic field strength, whereas the other does not. The first population is explained in terms of a model where the bow shock reflects ions which generate upstream foresh…
Multispacecraft observations of chorus emissions as a tool for the plasma density fluctuations' remote sensing
Khotyaintsev, Yuri; Dudok de Wit, Thierry; Agapitov, Oleksiy +4 more
Discrete ELF/VLF chorus emissions are the most intense electromagnetic plasma waves that are observed in the radiation belts and in the outer magnetosphere of the Earth. They are assumed to propagate approximately along the magnetic field lines and are generated in source regions in the vicinity of the magnetic equator and in minimum B pockets in …
Locations of boundaries of outer and inner radiation belts as observed by Cluster and Double Star
Dandouras, I.; Cao, J.; Ganushkina, N. Yu +1 more
Cluster CIS ion spectrograms measured during the period of the recent solar minimum between April 2007 and June 2009, when Cluster was deep in the radiation belts with its perigee as close as L = 2, are analyzed. The analysis is complemented by Double Star TC-1 satellite data from HIA ion spectrograms on perigee passes during the period of May 15,…
The relations between magnetospheric chorus and hiss inside and outside the plasmasphere boundary layer: Cluster observation
Zong, Qiugang; Xiao, Fuliang; Wang, Yongfu +3 more
Magnetospheric whistler mode emissions (chorus and hiss) can play an important role in acceleration and loss of energetic electrons by wave-particle interaction. Here we present a first report of two events in the simultaneous observations of chorus and hiss by the Cluster constellation. During the event of 30 August 2001, one spacecraft observed …
The influence of pickup protons, from interstellar neutral hydrogen, on the propagation of interplanetary shocks from the Halloween 2003 solar events to ACE and Ulysses: A 3-D MHD modeling study
Dryer, M.; Sun, W.; Intriligator, D. S. +3 more
We describe our 3-D, time-dependent, MHD solar wind model that we recently modified to include the physics of pickup protons from interstellar neutral hydrogen. The model has a time-dependent lower boundary condition, at 0.1 AU, that is driven by source surface map files through an empirical interface module. We describe the empirical interface an…
Analysis of Saturn kilometric radiation near a source center
Schippers, P.; Gurnett, D. A.; Lamy, L. +3 more
The Cassini spacecraft flew very near a source region of Saturn kilometric radiation (SKR) on day 73 of 2008, the second known encounter with a source region at high latitude. The radio and plasma wave instrument, Radio and Plasma Wave Science, observed intense kilometric emission in the extraordinary X mode, ordinary O mode, and Z mode. The elect…
Statistical characteristics of field-aligned currents in Saturn's nightside magnetosphere
Coates, A. J.; Dougherty, M. K.; Cowley, S. W. H. +3 more
During 2008, the Cassini spacecraft traversed Saturn's high-latitude field-aligned current systems on sequential north-south periapsis passes in the nightside magnetosphere. Two types of current systems have previously been identified, associated with antisymmetric azimuthal field signatures in the northern and southern hemispheres. The first exhi…
Stream particles as the probe of the dust-plasma-magnetosphere interaction at Saturn
Kempf, S.; Postberg, F.; Srama, R. +5 more
We analyze the dynamics and composition of Saturnian stream particles measured by the Cosmic Dust Analyser (CDA) onboard the Cassini spacecraft. To reconstruct the dynamical properties of Saturnian stream particles, we adopt a backward tracing method with in situ solar wind measurements to filter out the influence of the interplanetary magnetic fi…