Search Publications
Mixed particle acceleration at CME-driven shocks and flares
Zank, G. P.; Li, G.
A recent study of Cane et al. [2003] showed that in some intense SEP events, the time-intensity profiles exhibit two peaks, with an earlier one having a high Fe/O and a later one with a low Fe/O ratio. They suggested that these two-component events are due to CMEs and their accompanying flares occurring together, with the first peak being flare-re…
Global cooling and densification of the plasma sheet during an extended period of purely northward IMF on October 22-24, 2003
Wing, S.; Balogh, A.; Fujimoto, M. +6 more
The October 22-24, 2003 interplanetary magnetic cloud was characterized by an exceptionally long interval (~32 hours) of nearly purely northward interplanetary magnetic field (IMF). Following the northward IMF turning Cluster observed a gradual transition to a cold (<1 keV) and dense (~1-2 cm-3) plasma sheet (CDPS). Cluster observed …
In situ observations of a solar wind compression-induced hot plasma injection in Saturn's tail
Coates, A. J.; Krupp, N.; Dougherty, M. K. +5 more
During the Saturn orbit insertion (SOI) fly-through of the Cassini spacecraft, Saturn's magnetosphere underwent a significant corotating interaction region (CIR) related compression. Such compressions have recently been suggested to produce rapid bursts of tail reconnection, enhanced Saturn kilometric radiation (SKR), and consequent auroral dynami…
Plasma sheet formation during long period of northward IMF
Phan, Tai D.; Øieroset, Marit; Raeder, Joachim +2 more
We have studied the entry paths of solar wind plasma into the magnetosphere during an extended period of northward IMF using an OpenGGCM MHD simulation of the cold dense plasma sheet (CDPS) event observed on October 23, 2003 by the Cluster spacecraft. We find that high-latitude reconnection occurs tailward of both cusps between the IMF and geomagn…
How typical are atypical current sheets?
Balogh, A.; Zhang, T. L.; Klecker, B. +7 more
Using multi-satellite Cluster magnetic field data, we statistically examined how often an atypical, i.e., non-Harris type, current sheet is formed. We found that a cross-tail current sheet with an off-equatorial current density maximum, indicating bifurcation, is frequently formed in thin current sheets with a half thickness of ~1500 km. The occur…
Titan's ionosphere: Model comparisons with Cassini Ta data
Coates, A. J.; Luhmann, J. G.; Wahlund, J. -E. +13 more
On October 26, 2004, during its first encounter with Titan (Ta), the Cassini Orbiter moved from the dayside to the nightside with a closest approach altitude of 1174 km. In situ measurements of the main part of Titan's ionosphere were made by the Langmuir probe on the Cassini Radio and Plasma Wave Experiment (RPWS), while the Ion and Neutral Mass …
Radial evolution of cross helicity in high-latitude solar wind
Bavassano, B.; Matthaeus, W. H.; Bieber, J. W. +4 more
We employ a turbulence transport theory to explain the high-latitude radial evolution of cross helicity, or Alfvénicity, observed by the Ulysses spacecraft. Evolution is slower than at low latitudes due to weakened shear driving.
Quasi thermal noise spectroscopy in the inner magnetosphere of Saturn with Cassini/RPWS: Electron temperatures and density
Moncuquet, Michel; Meyer-Vernet, Nicole; Lecacheux, Alain +2 more
On 1 July 2004, the Cassini spacecraft performed its Saturn orbit insertion, twice crossing the equatorial plane between the G and F rings. The radio HF receiver observed a peak at the upper-hybrid frequency and weakly banded emissions having well-defined minima at gyroharmonics. We show that through most of the encounter, these emissions do not r…
Equatorial electron density measurements in Saturn's inner magnetosphere
Gurnett, D. A.; Persoon, A. M.; Dougherty, M. K. +4 more
Upper hybrid resonance emissions detected by the Radio and Plasma Wave Science (RPWS) instrument on the Cassini spacecraft are used to obtain electron densities on five equatorial orbits of Saturn at radial distances ranging from 3 to 9 saturnian radii (RS). The electron density profiles for these orbits show a highly repeatable radial …
Periodic intensity variations in global ENA images of Saturn
Krimigis, S. M.; Mitchell, D. G.; Paranicas, C. +4 more
During select time periods in orbit about Saturn, Cassini's Ion and Neutral Camera (INCA) has detected a periodic global ENA signal. Images taken during such periods reveal the presence of a rotating source component in addition to a steady-state component; both components have peak brightness in the midnight sector, when viewed from near dawn. We…