Search Publications
Spatial scale of high-speed flows in the plasma sheet observed by Cluster
Balogh, A.; Zhang, T. L.; Klecker, B. +9 more
Spatial gradients of high-speed flows in the midtail plasma sheet are determined using multipoint observations from the Cluster spacecraft along the ``dawn-dusk'' direction (perpendicular to the main flow and in the plane of the tail current sheet) and along the north-south direction. If we take the average or median of the spatial gradients and a…
Cluster observations of earthward flowing plasmoid in the tail
Balogh, A.; Glassmeier, K. -H.; Zhang, H. +10 more
The energetic electrons and ions embedded in Earthward-moving plasmoid structures have been observed. These plasmoids are associated with a rotational local Bz component (bi-polar) signature. Energetic electrons are found to be confined in a smaller spatial region than ions inside the plasmoid. Energetic ions and electrons seem to be a …
Orientation and propagation of current sheet oscillations
Sauvaud, J. -A.; Balogh, A.; Zhang, T. L. +6 more
Using the four-spacecraft Cluster system, we analyze rapid neutral sheet crossings near the Cluster apogee at about -18RE. In case studies of multiple oscillations of the locally quiet plasma sheet as well as in a statistical study of oscillations in dawn and dusk near-flank plasma sheet portions we typically obtain that locally these d…
A microscopic and nanoscopic view of storm-time chorus on 31 March 2001
Gurnett, D. A.; Pickett, J. S.; Santolík, O. +2 more
We investigate intense whistler-mode chorus emissions which occurred during the geomagnetic storm on 31 March 2001. We use multipoint measurements obtained by the Cluster spacecraft in the premidnight equatorial region outside the plasmasphere at a radial distance of 4 Earth radii (L = 4.0 - 4.2). Observed spatio-temporal variations of the directi…
Cluster observations of lower hybrid turbulence within thin layers at the magnetopause
Wahlund, J. -E.; Fazakerley, A. N.; André, M. +3 more
We use data from the Cluster satellites to study waves in the frequency range of ~2-150 Hz at the magnetopause. In addition to broad band wave turbulence we identify lower hybrid drift waves and whistler waves. Wave amplitudes maximize within narrow current sheets that are associated with density gradients and electron beams and that can be the se…
Anatomy of a flux transfer event seen by Cluster
Hasegawa, H.; Paschmann, G.; Sonnerup, B. U. Ö.
Data from Cluster are used to study the structure of a flux transfer event (FTE), seen near the northern cusp. We employ Grad-Shafranov reconstruction, using measured fields from all four spacecraft to produce a map of the FTE cross section. The FTE consists of a flux rope of approximate size 1RE and irregular shape, embedded in the mag…
Thin electron-scale layers at the magnetopause
Fazakerley, A. N.; André, M.; Vaivads, A. +2 more
We use data from the four Cluster satellites to examine the microphysics of a thin electron-scale layer discovered on the magnetospheric side of the magnetopause. Here the ion and electron motions are decoupled in a layer about 20 km (a few electron scales) wide, including currents and strong electric fields. In this layer the electrons are E × B …
Multi-spacecraft observations of diffuse ions upstream of Earth's bow shock
Klecker, B.; Kistler, L. M.; Lucek, E. A. +6 more
We report on simultaneous measurements of energetic ions upstream of Earth's quasi-parallel bow shock by Cluster during a 10 hour time period when the inter-spacecraft separation distance was between ~1 and ~1.5 Re. Using a bow shock model we determined for each 32 s averaged data set the distance of the Cluster 1 and Cluster 3 spacecra…
Reinterpretation of mirror modes as trains of slow magnetosonic solitons
Stasiewicz, Krzysztof
It is shown that large amplitude periodic oscillations of the magnetic field measured frequently by spacecraft in the magnetosheath, and interpreted as mirror-mode waves/structures, represent trains of slow-mode magnetosonic solitons. Nonlinear magnetosonic wave-trains with properties attributed previously to mirror-mode structures are obtained as…
Cluster survey of cusp reconnection and its IMF dependence
Lavraud, B.; Rème, H.; Dunlop, M. +3 more
We have surveyed the occurrence of tailward-of-the-cusp reconnection detected by Cluster as a function of the interplanetary magnetic field (IMF) clock angle. The survey covers 3 years (2001-2003) of cusp and magnetopause (MP) crossings and is restricted to periods of relatively stable IMF. Our survey indicates that the reconnection associated pla…