Search Publications
Characteristics of the near-tail dawn magnetopause and boundary layer
Klecker, B.; Vaivads, A.; Hasegawa, H. +6 more
The paper discusses properties of the near-tail dawnside and boundary layer, as obtained from Cluster plasma and magnetic field measurements during a single skimming orbit on 4 and 5 July 2001 that included 24 well-defined crossings by all four spacecraft. As a result of variations of the interplanetary magnetic field, the magnetic shear across th…
Modelling cosmic ray intensities along the Ulysses trajectory
Ferreira, S. E. S.; Potgieter, M. S.; Heber, B. +1 more
Time dependent cosmic ray modulation in the inner heliosphere is studied by comparing results from a 2-D, time-dependent cosmic ray transport model with Ulysses observations. A compound approach, which combines the effects of the global changes in the heliospheric magnetic field magnitude with drifts to establish a realistic time-dependence, in th…
Radial variation of whistler-mode chorus: first results from the STAFF/DWP instrument on board the Double Star TC-1 spacecraft
Santolík, O.; Yearby, K. H.; Cornilleau-Wehrlin, N. +2 more
We use the first measurements of the STAFF/DWP instrument on the Double Star TC-1 spacecraft to investigate whistler-mode chorus. We present initial results of a systematic study on radial variation of dawn chorus. The chorus events show an increased intensity at L parameter above 6. This is important for the possible explanation of intensificatio…
Dawn-dusk asymmetries and sub-Alfvénic flow in the high and low latitude magnetosheath
Dandouras, I.; Fazakerley, A. N.; Lucek, E. A. +4 more
We present the results of a statistical survey of the magnetosheath using four years of Cluster orbital coverage. Moments of the plasma distribution obtained from the electron and ion instruments together with magnetic field data are used to characterise the flow and density in the magnetosheath. We note two important differences between our surve…
Multi-spacecraft determination of wave characteristics near the proton gyrofrequency in high-altitude cusp
Wahlund, J. -E.; André, M.; Stenberg, G. +11 more
We present a detailed study of waves with frequencies near the proton gyrofrequency in the high-altitude cusp for northward IMF as observed by the Cluster spacecraft. Waves in this regime can be important for energization of ions and electrons and for energy transfer between different plasma populations. These waves are present in the entire cusp …
Wave particle interactions in the high-altitude polar cusp: a Cluster case study
Balogh, A.; Lavraud, B.; André, M. +5 more
On 23 March 2002, the four Cluster spacecraft crossed in close configuration (~100 km separation) the high-altitude (10 RE) cusp region. During a large part of the crossing, the STAFF and EFW instruments have detected strong electromagnetic wave activity at low frequencies, especially when intense field-aligned proton fluxes were detect…
Magnetopause current as seen by Cluster
Balogh, A.; Dunlop, M. W.
The four-spacecraft, magnetic field measurements on Cluster can be combined to produce an accurate determination of the electric current in the magnetopause boundary during stable magnetopause crossings. For events that are planar on the scale of the spacecraft configuration, the thickness of the current layer can be accurately estimated from its …
Transition from substorm growth to substorm expansion phase as observed with a radial configuration of ISTP and Cluster spacecraft
Sauvaud, J. -A.; Thomsen, M. F.; Klecker, B. +10 more
Transition from the growth phase to the substorm expansion during a well-isolated substorm with a strong growth phase is investigated using a unique radial (THEMIS-like) spacecraft constellation near midnight, including the probing of the tail current at ~16 RE with Cluster, of the transition region at ~9 RE with Geotail and …
Cluster observations of sudden impulses in the magnetotail caused by interplanetary shocks and pressure increases
Balogh, A.; Lucek, E.; Rème, H. +6 more
Sudden impulses (SI) in the tail lobe magnetic field associated with solar wind pressure enhancements are investigated using measurements from Cluster. The magnetic field components during the SIs change in a manner consistent with the assumption that an antisunward moving lateral pressure enhancement compresses the magnetotail axisymmetrically. W…
Double Star TC-1 observations of component reconnection at the dayside magnetopause: a preliminary study
Zhang, T. L.; Dandouras, I.; Zhang, H. +13 more
In spring 2004 Double Star TC-1 measured a number of reconnection signatures at the dayside low-latitude magnetopause (MP) when there was a notable By component in the magnetosheath. In a number of events we can show that reconnection was operating nearby TC-1 in the subsolar MP region. In this paper we describe three representative eve…