Search Publications
Magnetospheric configurations from a high-resolution data-based magnetic field model
Sitnov, M. I.; Tsyganenko, N. A.
We present first results of the magnetospheric magnetic field modeling, based on large sets of spacecraft data and a high-resolution expansion for the field of equatorial currents. In this approach, the field is expanded into a sum of orthogonal basis functions of different scales, capable to reproduce arbitrary radial and azimuthal variations of …
Energetic electron acceleration in the downstream reconnection outflow region
Balogh, A.; RèMe, H.; Daly, P. W. +5 more
Energetic electrons in an earthward reconnection outflow region have been observed by Cluster/Research with Adaptive Particle Imaging Detectors. We found a good correlation between the energetic electron enhancement and a normal magnetic field (Bz) enhancement within a 0.25-s time resolution. The large normal magnetic field is thought t…
Multi-point observations of the Hall electromagnetic field and secondary island formation during magnetic reconnection
Balogh, A.; Dandouras, I.; Eastwood, J. P. +7 more
A key feature of collisionless magnetic reconnection is the formation of Hall magnetic and electric field structure in the vicinity of the diffusion region. Here we present multi-point Cluster observations of a reconnection event in the near-Earth magnetotail where the diffusion region was nested by the Cluster spacecraft; we compare observations …
Cluster observations of waves in the whistler frequency range associated with magnetic reconnection in the Earth's magnetotail
Dandouras, I.; Lucek, E.; RèMe, H. +7 more
On 21 August 2002 the Cluster spacecraft encountered a quasi-collisionless magnetic reconnection event when it crossed the plasma sheet. Prior to the southward turning of magnetic field in the tailward flow, the weak whistler waves were first observed. The burst of whistler waves appeared about 30 s earlier than the southward turning. During magne…
Thinning and stretching of the plasma sheet
Petrukovich, A. A.; Balogh, A.; RèMe, H. +3 more
With Cluster observations in the magnetotail we study dynamics of plasma sheet thinning and stretching during 39 intervals associated with substorm growth phases. The cross-tail current density and normal magnetic field generally scale as Bn ∼ TpNp1/2/J0, but with frequent transient variations…
Magnetic field rotation analysis and the applications
Lucek, E.; Dunlop, M.; Liu, Z. X. +4 more
An analysis technique, termed MRA (magnetic rotation analysis), has been designed to probe three-dimensional magnetic field topology. It is based on estimating the gradient tensor of four-point measurements of the magnetic field which have been taken by the Cluster mission. The method first constructs the symmetrical magnetic rotation tensor and i…
Cluster and DMSP observations of SAID electric fields
Lucek, E.; Khotyaintsev, Y.; Kistler, L. +5 more
We report on magnetically conjugate Cluster and the Defense Meteorological Satellite Program (DMSP) satellite observations of subauroral ion drifts (SAID) during moderate geomagnetic activity levels on 8 April 2004. To our knowledge, the field-aligned separation of DMSP and Cluster (≈28,000 km) is the largest separation ever analyzed with respect …
Electrostatic structure around spacecraft in tenuous plasmas
Eriksson, A. I.; Cully, C. M.; Ergun, R. E.
Most satellite-based in situ plasma experiments are affected in some manner by the electrostatic structure surrounding the spacecraft. In order to better understand this structure, we have developed a fully three-dimensional self-consistent model that can accept realistic spacecraft geometry, including both thin (∼10-4 m) wires and long…
Taylor scale and effective magnetic Reynolds number determination from plasma sheet and solar wind magnetic field fluctuations
Walker, R. J.; Dasso, S.; Matthaeus, W. H. +2 more
Cluster data from many different intervals in the magnetospheric plasmas sheet and the solar wind are employed to determine the magnetic Taylor microscale from simultaneous multiple point measurements. For this study we define the Taylor scale as the square root of the ratio of the mean square magnetic field (or velocity) fluctuations to the mean …
Electron dynamics and cross-shock potential at the quasi-perpendicular Earth's bow shock
Lefebvre, Bertrand; Schwartz, Steven J.; Fazakerley, Andrew F. +1 more
The evolution of the electron distribution function through quasi-perpendicular collisionless shocks is believed to be dominated by the electron dynamics in the large-scale coherent and quasi-stationary magnetic and electric fields. We investigate the electron distributions measured on board Cluster by the Plasma Electron and Current Experiment (P…