Search Publications
Motion of the dipolarization front during a flow burst event observed by Cluster
Balogh, A.; Zhang, T. L.; Dandouras, I. +12 more
In this paper we study a flow burst event which took place during enhanced geomagnetic activity on July 22, 2001, when Cluster was located in the postmidnight magnetotail. The flow burst was associated with a clear dipolarization ahead of the high-speed part of the predominantly Earthward directed flow. Based on the analysis of the four spacecraft…
Four-point Cluster application of magnetic field analysis tools: The Curlometer
Balogh, A.; Glassmeier, K. -H.; Dunlop, M. W. +1 more
For the first time, the Cluster spacecraft have collected 3-D information on magnetic field structures at small to medium scales in the Earth's dayside magnetosphere. We focus here on the first application of the Curlometer (direct estimation of the electric current density from curl(B), using measured spatial gradients of the magnetic field) anal…
Spatiotemporal variability and propagation of equatorial noise observed by Cluster
Gurnett, D. A.; Pickett, J. S.; Maksimovic, M. +2 more
We report a multipoint case study of the electromagnetic equatorial noise observed by the Cluster project. High-resolution data were measured in three close points in space located in the morning sector of the outer plasmasphere. We demonstrate a narrow latitudinal extent of the emissions with a typical width of 2°, centered near the minimum-B equ…
A wavy twisted neutral sheet observed by CLUSTER
Balogh, A.; Zhang, T. L.; Glassmeier, K. -H. +2 more
From July to October 2001, the Cluster satellites were located within the magnetotail and crossings of the neutral sheet were frequently observed by the FGM instrument [Balogh et al., 2001]. The neutral sheet often appears to be moving relative to the spacecraft. Multiple crossings of the neutral sheet on August 3, 2001 are analysed. These neutral…
Fast flow during current sheet thinning
Balogh, A.; Zhang, T. L.; Klecker, B. +9 more
In this paper we report Cluster observation of a fast flow event in the plasma sheet associated with a small auroral substorm intensification at 1838 UT on August 12, 2001. Cluster, located in the plasma sheet, experienced significant thinning of the current sheet associated with a high-speed Earthward flow of 900 km/s. By using the four spacecraf…
Timing of magnetic reconnection initiation during a global magnetospheric substorm onset
Daly, P. W.; Dunlop, M. W.; Baker, D. N. +13 more
We have used a unique constellation of Earth-orbiting spacecraft and ground-based measurements in order to study a relatively isolated magnetospheric substorm event on August 27, 2001. Global ultraviolet images of the northern auroral region established the substorm expansion phase onset at 0408:19 (+/-1 min) UT. Concurrent measurements from the G…
Density modulated whistler mode emissions observed near the plasmapause
Santolik, O.; Parrot, M.; Andre, M. +4 more
Electron density fluctuations are regularly observed near the plasmapause together with electromagnetic waves below the electron cyclotron frequency (usually called hiss or chorus). Instruments on board CLUSTER spacecraft often observe two such emission bands with fluctuating wave intensities that suggest wave ducting in density enhancements as we…
Cluster observations of the exterior cusp and its surrounding boundaries under northward IMF
Lundin, R.; Sauvaud, J. -A.; Escoubet, C. P. +18 more
We have studied in detail multi-spacecraft observations of the exterior cusp on 04 February 2001, during a steady northward Interplanetary Magnetic Field (IMF) interval. At a radial distance of 11 Re, Cluster encountered a well-bounded region where the magnetic field exhibited very low diamagnetic values and the ions displayed high levels of isotr…
Four-point Cluster application of magnetic field analysis tools: The discontinuity analyzer
Balogh, A.; Glassmeier, K. -H.; Dunlop, M. W.
The Cluster spacecraft have collected 3-D information on magnetic field structures at small to medium scales (100-1000 km) in the Earth's dayside magnetosphere, magnetosheath, and near solar wind. We focus here on the first application of the discontinuity analyzer analysis technique (determination of the geometry and motion of magnetic discontinu…
Coordinated ground-based and Cluster observations of large amplitude global magnetospheric oscillations during a fast solar wind speed interval
Balogh, A.; Bale, S. D.; Yeoman, T. K. +10 more
We present magnetospheric observations of very large amplitude global scale ULF waves, from 9 and 10 December 2000 when the upstream solar wind speed exceeded 600 km/s. We characterise these ULF waves using ground-based magnetometer, radar and optical instrumentation on both the dawn and dusk flanks; we find evidence to support the hypothesis that…