Search Publications
Multiple triangulation analysis: application to determine the velocity of 2-D structures
Zong, Q. -G.; Cao, J. B.; Shi, Q. Q. +4 more
In order to avoid the ambiguity of the application of the Triangulation Method (multi-spacecraft timing method) to two-dimensional structures, another version of this method, the Multiple Triangulation Analysis (MTA) is used, to calculate the velocities of these structures based on 4-point measurements. We describe the principle of MTA and apply t…
Statistical study of the location and size of the electron edge of the Low-Latitude Boundary Layer as observed by Cluster at mid-altitudes
Fazakerley, A. N.; Klecker, B.; Owen, C. J. +2 more
The nature of particle precipitations at dayside mid-altitudes can be interpreted in terms of the evolution of reconnected field lines. Due to the difference between electron and ion parallel velocities, two distinct boundary layers should be observed at mid-altitudes between the boundary between open and closed field lines and the injections in t…
Coordinated observation of field line resonance in the mid-tail
Russell, C. T.; Balogh, A.; Rème, H. +9 more
Standing Alfvén waves of 1.1 mHz (~15 min in period) were observed by the Cluster satellites in the mid-tail during 06:00-07:00 UT on 8 August 2003. Pulsations with the same frequency were also observed at several ground stations near Cluster's footpoint. The standing wave properties were determined from the electric and magnetic field measurement…
Reconnection and energetic particles at the edge of the exterior cusp
Asikainen, T.; Mursula, K.
In this paper we study flux transfer events (FTE) observed at the post-noon edge of the exterior cusp region by Cluster satellites. During the outbound dayside orbit on 2 February 2003, intense bursts of energetic particles were observed in close conjuction with magnetic field FTE signatures by the RAPID instrument onboard the Cluster 4. The pitch…
Substorm topology in the ionosphere and magnetosphere during a flux rope event in the magnetotail
Balogh, A.; Nakamura, R.; Rème, H. +4 more
On 13 August 2002, at ~23:00 UT, about 10 min after a substorm intensification, Cluster observes a flux rope in the central magnetotail, followed by a localised fast flow event about oneminute later. Associated with the flux rope event, a traveling compression region (TCR) is seen by those Cluster spacecraft which reside in the lobe. In the conjug…
On the structure of field-aligned currents in the mid-altitude cusp
Fazakerley, A. N.; Owen, C. J.; Marchaudon, A. +3 more
We analyse two crossings of the polar cusp at mid-altitudes (≈4 RE) by Cluster in order to study the structure of field-aligned currents associated with the injection of magnetosheath plasma. The current density is deduced independently from magnetic field and from particle flux measurements. In both cases the data are carefully tested.…
Two distinct energetic electron populations of different origin in the Earth's magnetotail: a Cluster case study
Zong, Q. -G.; Sarris, E. T.; Fritz, T. A. +1 more
Energetic electrons (E≥30 keV) travelling along and perpendicular to the magnetic field lines have been observed in the magnetotail at L~17:00 and 22:00 MLT during the recovery phase of a storm-time substorm on 7 October 2002. Three-dimensional electron distributions of the full unit sphere obtained from the IES/RAPID sensor system demonstrated a …
Evidence of standing waves during a Pi2 pulsation event observed on Cluster
Blomberg, L. G.; Collier, A. B.; Hughes, A. R. W. +1 more
Observations of Pi2 pulsations at middle and low latitudes have been explained in terms of cavity mode resonances, whereas transients associated with field-aligned currents appear to be responsible for the high latitude Pi2 signature. Data from Cluster are used to study a Pi2 event observed at 18:09 UTC on 21 January 2003, when three of the satell…
Global manifestations of a substorm onset observed by a multi-satellite and ground station network
Escoubet, C. P.; Liu, Z. X.; Frey, H. U. +6 more
With a favorable constellation of spacecraft and ground stations, a study is made on the global manifestations of a substorm onset. The onset occurred simultaneously and conjugately in both hemispheres, confirmed by observations of the auroral breakup from IMAGE FUV-WIC and a sudden intensification of a westward electrojet from ground-based magnet…
Characteristics of merging at the magnetopause inferred from dayside 557.7-nm all-sky images: IMF drivers of poleward moving auroral forms
Winningham, J. D.; Balogh, A.; Farrugia, C. J. +10 more
We combine in situ measurements from Cluster with high-resolution 557.7 nm all-sky images from South Pole to investigate the spatial and temporal evolution of merging on the dayside magnetopause. Variations of 557.7 nm emissions were observed at a 6 s cadence at South Pole on 29 April 2003 while significant changes in the Interplanetary Magnetic F…