Search Publications
Kinetic properties of heavy solar wind ions from Ulysses-SWICS
Zurbuchen, T. H.; von Steiger, R.
The kinetic properties of heavy ions in the solar wind reflect the plasma processes governing the solar wind in the heliosphere. We use Ulysses-SWICS data that resolve heavy ions in a wide range of mass-per-charge values, 2 <= m/q <= 9.33, to investigate the heavy ions and their dynamic evolution throughout the heliosphere. While at 1 AU the…
A steep fan at Coprates Catena, Valles Marineris, Mars, as seen by HRSC data
Neukum, G.; Hauber, E.; Reiss, D. +4 more
We investigate a steep fan-like deposit in the Coprates Catena region, using the new High Resolution Stereo Camera (HRSC) data and other Martian data sets. Water flowing in a 45-km-long sapping valley entered a deep trough and formed a stepped fan 1100-m-high above the trough floor with a mean slope of 7.4°. The origin of the fan is uncertain. How…
Kinetic aspects of foreshock cavities
Schwartz, Steven J.; Meziane, Karim; Horbury, Timothy S. +2 more
We have investigated the kinetic signatures within, and at the edges of, a foreshock cavity. Such cavities are believed to be formed when an isolated collection of interplanetary magnetic field lines connect to quasi-parallel regions of the Earth's bow shock, allowing energetic ions to flow upstream and excavate a local cavity. Observations by the…
Formation of Saturn's ring spokes by lightning-induced electron beams
Krupp, N.; Woch, J.; Fränz, M. +10 more
Spokes are near-linear markings sometimes visible on Saturn's rings. They are widely accepted as being electrostatically-levitated sheets of ~0.6 micron-radius charged grains. Previously-suggested causes of the grains' charging do not agree with all spoke characteristics, which include their rapid generation, localized formation primarily in Satur…
A structural study of an interior layered deposit in southwestern Candor Chasma, Valles Marineris, Mars, using high resolution stereo camera data from Mars Express
Scholten, F.; Neukum, G.; Hauber, E. +5 more
An interior layered deposit (ILD) within Western Candor Chasma of Valles Marineris, Mars, is examined using data from the High Resolution Stereo Camera of the Mars Express mission. Most ILD layers dip in the same direction as the topographic slope. Exposed, rotated fault blocks of basement lithology appear to penetrate the cover of this ILD deposi…
Temporal evolution of a staircase ion signature observed by Cluster in the mid-altitude polar cusp
Berchem, J.; Escoubet, C. P.; Pitout, F. +9 more
We use the Cluster string of pearls configuration to investigate temporal variations of ion precipitation in the mid-altitude polar cusp. On 7 Aug. 2004, Cluster 4 was moving poleward through the Northern cusp, followed by Cluster 1, Cluster 2, and finally Cluster 3. The Wind spacecraft detected a Southward turning of the Interplanetary Magnetic F…
Cluster observations of broadband electromagnetic waves in and around a reconnection region in the Earth's magnetotail current sheet
Walsh, A. P.; Freeman, M. P.; Petkaki, P.
We present an analysis of the electric and magnetic wave spectra on kinetic scales during several crossings of a reconnecting current sheet. The spectra were measured from 1 Hz or less up to 4096 Hz by the EFW, FGM and STAFF instruments onboard the Cluster spacecraft between 3 and 4 UT on 11 October 2001. During the event plasma flows of order of …
Spatial gradients in the plasmasphere from Cluster
Dunlop, M. W.; Décréau, P. M. E.; De Keyser, J. +2 more
The Cluster mission allows the study of the plasmasphere with four-point measurements, including its overall density distribution, plasmaspheric plumes close to the plasmapause, and density irregularities inside the plasmasphere. The purpose of this letter is to examine the geometry and orientation of the overall density structure and of the magne…
A test-particle model of the atmosphere/ionosphere system of Saturn's main rings
Tokar, R. L.; Johnson, R. E.; Young, D. T. +4 more
The first pass of the Cassini orbiter near the A and B rings of Saturn, formed mainly by H2O ice particles, revealed the presence of an ionosphere composed of O+ and O2+ ions. Such a result suggests the existence of an atmospheric halo made up of molecular oxygen surrounding the rings. It is produced by …
Multiplet structure of acceleration processes in the distant magnetotail
Zelenyi, L. M.; Sauvaud, J. -A.; Grigorenko, E. E. +1 more
We have studied ion distributions measured in the Plasma Sheet Boundary Layer (PSBL) of the Earth's magnetotail by the Cluster spacecraft at X ~ -15Re. Field-aligned ion beams (beamlets) accelerated in the magnetotail to energies of ~30keV are typically observed within the interface region between the Plasma Sheet (PS) and the magnetotail lobes. P…