Search Publications
Saturn chorus intensity variations
Schippers, P.; Gurnett, D. A.; Hospodarsky, G. B. +4 more
mode chorus plasma wave emissions have been observed at Saturn near the magnetic equator and the source region. During crossings of the magnetic equator along nearly constant L shells, the Cassini Radio and Plasma Wave Science Investigation often observes a local decrease in whistler mode intensity and bandwidth closest to the magnetic equator, wh…
Cluster observations near reconnection X lines in Earth's magnetotail current sheet
Fazakerley, A. N.; Gurgiolo, C.; Goldstein, M. L. +2 more
Magnetic reconnection is an efficient way to convert magnetic energy into particle energy. In this paper, we use Cluster thermal electron and ion measurements in the vicinity of a reconnection X line to delineate the structure of the reconnection current sheet. Multispacecraft observations made by Cluster on 18 August 2002 indicate that an X line …
On the relation between asymmetries in the ring current and magnetopause current
Haaland, S.; Gjerloev, J.
Motion of charged particles in the Earth's magnetosphere sets up a system of currents. Current continuity requires that these currents are closed, either locally or via other current systems. In this paper, we have investigated whether magnetopause surface currents can contribute to ring current closure. Using measurements from the Cluster constel…
Cluster observations of hot flow anomalies with large flow deflections: 2. Bow shock geometry at HFA edges
Zong, Qiugang; Zhang, Hui; Wang, Shan
Case and statistical studies of the bow shock geometry at hot flow anomaly (HFA) edges have been performed based on 87 HFAs with large flow deflections observed by the Cluster C1 spacecraft from 2003 to 2009. The results suggest that HFAs can be formed at both quasi-parallel and quasi-perpendicular shocks. In an accompanying paper, we show that th…
Method for inferring the axis orientation of cylindrical magnetic flux rope based on single-point measurement
Zhang, T. L.; Zong, Q. -G.; Dunlop, M. W. +6 more
We develop a new simple method for inferring the orientation of a magnetic flux rope, which is assumed to be a time-independent cylindrically symmetric structure via the direct single-point analysis of magnetic field structure. The model tests demonstrate that, for the cylindrical flux rope regardless of whether it is force-free or not, the method…
A comparison of magnetic overshoots at the bow shocks of Mercury and Saturn
Anderson, B. J.; Masters, A.; Korth, H. +5 more
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft at Mercury and the Cassini spacecraft at Saturn provide us with orbiters around planets at more diverse heliocentric distances than ever before. The dramatically different solar wind conditions at these two planets should mean that Mercury's bow shock is consi…
Observational study of the cooling behavior of interstellar helium pickup ions in the inner heliosphere
Bochsler, Peter; Gloeckler, George; Isenberg, Philip A. +4 more
velocity distribution of interstellar pickup ions (PUIs) has typically been described as evolving through fast pitch angle scattering followed by adiabatic cooling while being transported radially outward with the solar wind. In combination, the ionization rate, which controls the radial profile of the interstellar neutrals, and the cooling proces…
Cluster observations of whistler waves correlated with ion-scale magnetic structures during the 17 August 2003 substorm event
Sauvaud, J. -A.; Le Contel, O.; Fontaine, D. +4 more
We provide evidence of the simultaneous occurrence of large-amplitude, quasi-parallel whistler mode waves and ion-scale magnetic structures, which have been observed by the Cluster spacecraft in the plasma sheet at 17 Earth radii, during a substorm event. It is shown that the magnetic structures are characterized by both a magnetic field strength …
Directionality and variability of energetic neutral hydrogen fluxes observed by Mars Express
Barabash, S.; Futaana, Y.; Grigoriev, A. +2 more
Using data collected by the neutral particle detector of the analyzer of space plasmas and energetic atoms on board Mars Express, we establish the global morphology of hydrogen energetic neutral atom (ENA) fluxes. The observations were conducted in March-July 2004 and reveal that low flux ENAs (<5×105cm-2s-1sr
Statistical properties of planetary heavy-ion precipitations toward the Martian ionosphere obtained from Mars Express
Barabash, Stas; Futaana, Yoshifumi; Seki, Kanako +5 more
The interplanetary magnetic field (IMF) embedded in the solar wind interacts with the Martian crustal magnetic field and atmosphere. The IMF orientation is one of the important parameters to control the acceleration and precipitation of planetary heavy ions (PHIs). We statistically investigate the effects of the IMF orientation on PHI precipitatio…