Search Publications
Scale sizes of intense auroral electric fields observed by Cluster
Nilsson, H.; Buchert, S.; Karlsson, T. +4 more
The scale sizes of intense (>0.15 V/m, mapped to the ionosphere), high-altitude (4-7 RE geocentric distance) auroral electric fields (measured by the Cluster EFW instrument) have been determined in a statistical study. Monopolar and bipolar electric fields, and converging and diverging events, are separated. The relations between the…
Low frequency wave sources in the outer magnetosphere, magnetosheath, and near Earth solar wind
Fränz, M.; Glassmeier, K. -H.; Décréau, P. M. E. +2 more
The interaction of the solar wind with the Earth magnetosphere generates a broad variety of plasma waves through different mechanisms. The four Cluster spacecraft allow one to determine the regions where these waves are generated and their propagation directions. One of the tools which takes full advantage of the multi-point capabilities of the Cl…
Spatial structure of plasma flow associated turbulence in the Earth's plasma sheet
Nakamura, R.; Lucek, E. A.; Takada, T. +5 more
Using Cluster multipoint magnetic and plasma measurements we analyze the spatial structure of plasma flow-associated turbulence on 26 September 2005. The fortunate relative configuration of the spacecraft and the plasma flow allowed for the first time to compare the scale evolution of statistical moments both at the boundary and in the central par…
The magnetic structure of an earthward-moving flux rope observed by Cluster in the near-tail
Lucek, E.; Dunlop, M.; Liu, Z. X. +6 more
We investigate the magnetic structure of a small earthward-moving flux rope observed by Cluster in the near-Earth plasma sheet through application of the Grad-Shafranov (GS) technique to reconstruct the transverse magnetic field distribution perpendicular to the flux rope axis at X=-14.75 RE. We find that the principal axis of the flux …
IMF dependence of the open-closed field line boundary in Saturn's ionosphere, and its relation to the UV auroral oval observed by the Hubble Space Telescope
Alexeev, I. I.; Belenkaya, E. S.; Badman, S. V. +4 more
We study the dependence of Saturn's magnetospheric magnetic field structure on the interplanetary magnetic field (IMF), together with the corresponding variations of the open-closed field line boundary in the ionosphere. Specifically we investigate the interval from 8 to 30 January 2004, when UV images of Saturn's southern aurora were obtained by …
Internal structure and spatial dimensions of whistler wave regions in the magnetopause boundary layer
Lundin, R.; André, M.; Stenberg, G. +9 more
We use whistler waves observed close to the magnetopause as an instrument to investigate the internal structure of the magnetopause-magnetosheath boundary layer. We find that this region is characterized by tube-like structures with dimensions less than or comparable with an ion inertial length in the direction perpendicular to the ambient magneti…
A quantitative test of Jones NTC beaming theory using CLUSTER constellation
Grimald, S.; Décréau, P. M. E.; Canu, P. +4 more
Non-thermal continuum (NTC) radiation is, with auroral kilometric radiation (AKR), one of the two electromagnetic emissions generated within the Earth's magnetosphere and radiated into space. The location of the source of NTC has been sought for several decades, with only limited success. The constellation formed by the four CLUSTER spacecraft pro…
Prelude to THEMIS tail conjunction study
Kistler, L. M.; Dunlop, M. W.; Rème, H. +8 more
A close conjunction of several satellites (LANL, GOES, Polar, Geotail, and Cluster) distributed from the geostationary altitude to about 16 RE downstream in the tail occurred during substorm activity as indicated by global auroral imaging and ground-based magnetometer data. This constellation of satellites resembles what is planned for …
An auroral westward flow channel (AWFC) and its relationship to field-aligned current, ring current, and plasmapause location determined using multiple spacecraft observations
Wild, J. A.; Lester, M.; Lucek, E. A. +3 more
An auroral westward flow channel (AWFC) is a latitudinally narrow channel of unstable F-region plasma with intense westward drift in the dusk-to-midnight sector ionosphere. AWFCs tend to overlap the equatorward edge of the auroral oval, and their life cycle is often synchronised to that of substorms: they commence close to substorm expansion phase…
Polar and Cluster observations of a dayside inverted-V during conjunction
Frahm, R. A.; Khotyaintsev, Y.; Menietti, J. D. +2 more
We investigate particle and fields data during a conjunction of the Polar and Cluster spacecraft. This conjunction occurs near the dayside cusp boundary layer when a dayside inverted-V was observed in the particle data of both satellites. Electron, ion, electric field, and magnetic field data from each satellite confirm that the dayside inverted-V…