Search Publications
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…
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…
Four spacecraft measurements of the quasiperpendicular terrestrial bow shock: Orientation and motion
Balogh, A.; Horbury, T. S.; Lucek, E. A. +5 more
Measurements of the magnetic field at the four Cluster spacecraft, typically separated by ~600 km, during bow shock crossings allow the orientation and motion of this structure to be estimated. Results from 48 clean and steady quasiperpendicular crossings during 2000 and 2001, covering local times from 0600 to 1700, reveal the bow shock normal to …
Magnetospheric responses to sudden and quasiperiodic solar wind variations
Kim, K. -H.; Andre, M.; Mozer, F. S. +5 more
On April 13 (day 103), 2001, 0700-1400 UT, the Polar satellite experienced different plasma regimes (i.e., magnetosphere, magnetosheath, and solar wind) because of the solar wind dynamic pressure variations and its high orbital inclination near the subsolar magnetopause meridian. When Polar was in the magnetosheath, quasiperiodic spacecraft potent…
Cluster observations of the heliospheric current sheet and an associated magnetic flux rope and comparisons with ACE
Balogh, A.; Eastwood, J. P.; Dunlop, M. W. +1 more
Cluster and ACE magnetic field measurements from the 13 February 2001 are presented. On this day the four Cluster spacecraft made two crossings of the heliospheric current sheet (HCS) while in the solar wind and observed a large-scale rotation of the magnetic field in the magnetosheath. These features were also observed by ACE upstream of the Eart…
Observation of the terrestrial bow shock in quasi-electrostatic subshock regime
Balogh, A.; Eriksson, A.; Walker, S. N. +8 more
Electric field measurements made on board the four Cluster II satellites are used to estimate the spatial scale of the electrostatic potential in the front of the terrestrial bow shock in the quasi-perpendicular regime. High-amplitude electric fields (up to 70 mV m-1) were measured at the shock fronts encountered on 31 March 2001. The m…
Motion of auroral ion outflow structures observed with CLUSTER and IMAGE FUV
Lundin, R.; Winningham, J. D.; Dandouras, I. +22 more
During February 2001 the CLUSTER satellites recorded a number of perigee passes through the midnight auroral zone. We concentrate on one pass, on 23 February 2001, when structured outflow was observed. Simultaneous observations of the aurora were available from the FUV instrument on IMAGE. The features in the ion outflow observed by the Cluster Io…