Search Publications
Spatio-temporal structure of storm-time chorus
Gurnett, D. A.; Pickett, J. S.; Parrot, M. +2 more
We discuss chorus emissions measured by the four Cluster spacecraft at close separations during a geomagnetically disturbed period on 18 April 2002. We analyze the lower band of chorus below one half of the electron cyclotron frequency, measured at a radial distance of 4.4 Earth's radii, within a 2000 km long source region located close to the equ…
Current sheet structure near magnetic X-line observed by Cluster
Balogh, A.; Zhang, T. L.; Klecker, B. +9 more
During the interval 0947-0951 UT on 1 October 2001, when Cluster was located at X GSM = -16.4 R E near Z GSM = 0 in the pre-midnight magnetotail, the Cluster barycenter crosses the neutral sheet four times. High speed proton flow, with reversal from tailward to Earthward, was detected during the crossings. Us…
Current sheet flapping motion and structure observed by Cluster
Balogh, A.; Zhang, T. L.; André, M. +8 more
Fast vertical flapping oscillations of the plasma sheet have been observed by Cluster on September 26, 2001. The flapping motion had vertical speeds exceeding 100 km/s, an amplitude in excess of 1 RE and a quasiperiod of ~3 min. The current sheet was mostly tilted in the Y-Z plane (with the tilt sometimes exceeding 45°). The waves had t…
First results obtained by the Cluster STAFF experiment
Maksimovic, M.; Chust, T.; de Conchy, Y. +20 more
The Spatio Temporal Analysis of Field Fluctuations (STAFF) experiment is one of the five experiments, which constitute the Cluster Wave Experiment Consortium (WEC). STAFF consists of a three-axis search coil magnetometer to measure magnetic fluctuations at frequencies up to 4 kHz, a waveform unit (up to either 10 Hz or 180 Hz) and a Spectrum Analy…
Cluster observation of a bifurcated current sheet
Balogh, A.; Zhang, T. L.; Nakamura, R. +4 more
The current sheet structure and motion at XGSM = -19.5 RE, observed by Cluster/FGM during 1055-1107 UT on 29 August 2001, is examined. It is found that during the interval 1055-1102 UT the current sheet moves vertically up and down with a velocity of about 60 km/s. During this interval the current sheet has a bifurcated struc…
Continuous magnetic reconnection at Earth's magnetopause
Fuselier, S. A.; Mende, S. B.; Frey, H. U. +1 more
The most important process that allows solar-wind plasma to cross the magnetopause and enter Earth's magnetosphere is the merging between solar-wind and terrestrial magnetic fields of opposite sense-magnetic reconnection. It is at present not known whether reconnection can happen in a continuous fashion or whether it is always intermittent. Solar …
Simultaneous Cluster and IMAGE observations of cusp reconnection and auroral proton spot for northward IMF
Lundin, R.; Sauvaud, J. -A.; Balogh, A. +22 more
On March 18, 2002, under northward interplanetary magnetic field (IMF) and high (~15 nPa) solar wind dynamic pressure conditions, Cluster observed reconnection signatures and the passage of an X-line at the large (~175°) magnetic-shear high-latitude magnetopause (MP). The observations are consistent with the occurrence of a reconnection site tailw…
Transverse dimensions of chorus in the source region
Gurnett, D. A.; Santolík, O.
We report measurement of whistler-mode chorus by the four Cluster spacecraft at close separations. We focus our analysis on the generation region close to the magnetic equatorial plane at a radial distance of 4.4 Earth's radii. We use both linear and rank correlation analysis to define perpendicular dimensions of the sources of chorus elements bel…
Analyses on the geometrical structure of magnetic field in the current sheet based on cluster measurements
Balogh, A.; Baker, D. N.; Wang, X. +5 more
The geometrical structure of the magnetic field is a critical character in the magnetospheric dynamics. Using the magnetic field data measured by the Cluster constellation satellites, the geometrical structure including the curvature radius, directions of curvature, and normal of the osculating planes of the magnetic field lines within the current…
Solitary potential structures observed in the magnetosheath by the Cluster spacecraft
Gurnett, D. A.; Balogh, A.; Pickett, J. S. +4 more
Bipolar pulses of ~ 25-100 µs in duration have been observed in the wave electric field data obtained by the Wideband plasma wave instrument on the Cluster spacecraft in the dayside magnetosheath. These pulses are similar in almost all respects to those observed on several spacecraft over the last few years. They represent solitary potential struc…