Search Publications
A new technique for determining orientation and motion of a 2-D, non-planar magnetopause
Marghitu, O.; Klecker, B.; Scholer, M. +3 more
For a four-point mission like Cluster, the differences in position and time when the satellites detect the magnetopause or any other discontinuity, can be used to infer the discontinuity local orientation, thickness and motion. This timing technique, commonly assuming a planar geometry, offers an independent check for various single-spacecraft tec…
Corrigendum to "Substorm activity in Venus's magnetotail" published in Ann. Geophys., 27, 2321-2330, doi:10.5194/angeo-27-2321-2009, 2009
Barabash, S.; Futaana, Y.; Zhang, T. L. +5 more
A re-evaluation of the reconnection event reported by Volwerk et al. (2009) shows that the original interpretation of the magnetic field data as quadrupolar Hall-current signatures around a reconnection site was mistaken. It could be interpreted as the signature of reconnection in the presence of a guide field. The path of VEX through the active r…
Geomagnetic activity effects on plasma sheet energy conversion
Dandouras, I.; Hamrin, M.; Norqvist, P. +4 more
In this article we use three years (2001, 2002, and 2004) of Cluster plasma sheet data to investigate what happens to localized energy conversion regions (ECRs) in the plasma sheet during times of high magnetospheric activity. By examining variations in the power density, E·J, where E is the electric field and J is the current density obtained by …
The large-scale magnetospheric electric field observed by Double Star TC-1
Rème, H.; Carr, C.; Liu, Z. X. +4 more
The relationship between the average structure of the inner magnetospheric large-scale electric field and geomagnetic activity levels has been investigated by Double Star TC-1 data for radial distances ρ between 4.5 RE and 12.5 RE and MLT between 18:00 h and 06:00 h from July to October in 2004 and 2005. The sunward component…
Deriving the radial distances of wide coronal mass ejections from elongation measurements in the heliosphere - application to CME-CME interaction
Vourlidas, A.; Lugaz, N.; Roussev, I. I.
We present general considerations regarding the derivation of the radial distances of coronal mass ejections (CMEs) from elongation angle measurements such as those provided by SECCHI and SMEI, focusing on measurements in the Heliospheric Imager 2 (HI-2) field of view (i.e. past 0.3 AU). This study is based on a three-dimensional (3-D) magneto-hyd…
Evolution of dipolarization in the near-Earth current sheet induced by Earthward rapid flux transport
Dandouras, I.; André, M.; Klecker, B. +7 more
We report on the evolution of dipolarization and associated disturbances of the near-Earth current sheet during a substorm on 27 October 2007, based upon Cluster multi-point, multi-scale observations of the night-side plasma sheet at X~-10 RE. Three dipolarization events were observed accompanied by activations on ground magnetograms at…
Survey of cold ionospheric outflows in the magnetotail
André, M.; Eriksson, A. I.; Cully, C. M. +4 more
Low-energy ions escape from the ionosphere and constitute a large part of the magnetospheric content, especially in the geomagnetic tail lobes. However, they are normally invisible to spacecraft measurements, since the potential of a sunlit spacecraft in a tenuous plasma in many cases exceeds the energy-per-charge of the ions, and little is theref…
Plasma boundary variability at Mars as observed by Mars Global Surveyor and Mars Express
Barabash, S.; Fränz, M.; Lester, M. +4 more
We have used Mars Express (MEX) and Mars Global Surveyor (MGS) simultaneous and non-simultaneous measurements to study the Martian plasma environment. In particular, we have derived quantitative expressions for the altitude of the terminator bow shock (BS) and magnetic pileup boundary (MPB) as functions of solar wind dynamic pressure, crustal magn…
Mirror structures above and below the linear instability threshold: Cluster observations, fluid model and hybrid simulations
Budnik, E.; Dandouras, I.; Génot, V. +6 more
Using 5 years of Cluster data, we present a detailed statistical analysis of magnetic fluctuations associated with mirror structures in the magnetosheath. We especially focus on the shape of these fluctuations which, in addition to quasi-sinusoidal forms, also display deep holes and high peaks. The occurrence frequency and the most probable locati…
Thin embedded current sheets: Cluster observations of ion kinetic structure and analytical models
Malova, H. V.; Petrukovich, A. A.; Zelenyi, L. M. +3 more
Kinetic structure of embedded thin horizontal current sheets is investigated. Current density estimated by curlometer technique is in general agreement with a sum of electron and proton currents. Embedding of observed thin current sheets in the much wider plasma sheet is apparent in the current density profiles. Ion velocity distributions consist …