Search Publications
Cross-field flow and electric potential in a plasma slab
Roth, M.; De Keyser, J.; Echim, M.
We consider cross-field plasma flow inside a field-aligned plasma slab embedded in a uniform background in a 1-dimensional geometry. This situation may arise, for instance, when long-lasting reconnection pulses inject plasma into the inner magnetosphere. The present paper presents a detailed analysis of the structure of the interfaces that separat…
Spatial spreading of magnetospherically reflected chorus elements in the inner magnetosphere
Krasnoselskikh, V.; Breuillard, H.; Agapitov, O. +3 more
Chorus-type whistler waves are known to be generated in the vicinity of the magnetic equator, in the low-density plasma trough region. These wave packets propagate towards the magnetic poles, deviating from the magnetic field lines, before being eventually reflected at higher latitudes. Magnetospheric reflection of whistler waves results in bounce…
Electric potential differences across auroral generator interfaces
De Keyser, J.; Echim, M.
Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated) depends on the properties of the plasmas on either side of the interface, as well as on the total electric potenti…
Dispersion relation of electromagnetic ion cyclotron waves using Cluster observations
Walker, S. N.; Balikhin, M. A.; Shprits, Y. Y. +1 more
Multi-point wave observations on Cluster spacecraft are used to infer the dispersion relation of electromagnetic ion cyclotron (EMIC) waves. In this study we use a phase differencing method and observations from STAFF and WHISPER during a well-studied event of 30 March 2002. The phase differencing method requires the knowledge of the direction of …
Refilling process in the plasmasphere: a 3-D statistical characterization based on Cluster density observations
Lointier, G.; Rauch, J. -L.; Décréau, P. M. E. +4 more
The Cluster mission offers an excellent opportunity to investigate the evolution of the plasma population in a large part of the inner magnetosphere, explored near its orbit's perigee, over a complete solar cycle. The WHISPER sounder, on board each satellite of the mission, is particularly suitable to study the electron density in this region, bet…
Double cusp encounter by Cluster: double cusp or motion of the cusp?
Berchem, J.; Escoubet, C. P.; Pitout, F. +12 more
Modelling plasma entry in the polar cusp has been successful in reproducing ion dispersions observed in the cusp at low and mid-altitudes. The use of a realistic convection pattern, when the IMF-By is large and stable, allowed Wing et al. (2001) to predict double cusp signatures that were subsequently observed by the DMSP spacecraft. In…
A comparison of bow shock models with Cluster observations during low Alfvén Mach number magnetic clouds
Kilpua, E. K. J.; Turc, L.; Fontaine, D. +2 more
Magnetic clouds (MCs) are very geoeffective solar wind structures. Their properties in the interplanetary medium have been extensively studied, yet little is known about their characteristics in the Earth's magnetosheath. The Cluster spacecraft offer the opportunity to observe MCs in the magnetosheath, but before MCs reach the magnetosphere, their…
Coherent amplitude modulation of electron-beam-driven Langmuir waves
Baumgärtel, K.
A linear approach to the phenomenon of irregular amplitude modulation of beam-driven Langmuir waves, developed in a previous paper, is extended to explain periodic modulation as well. It comes about by beating of the fastest growing mode of the instability with beam-aligned plasma oscillations. They are naturally generated in a uniform domain of b…
Mapping of the quasi-periodic oscillations at the flank magnetopause into the ionosphere
Nykyri, K.; Moore, T. W.; Dougal, E. R.
We have estimated the ionospheric location, area, and travel time of quasi-periodic oscillations originating from the magnetospheric flanks. This was accomplished by utilizing global and local MHD models and Tsyganenko semi-empirical magnetic field model on multiple published and four new cases believed to be caused by the Kelvin-Helmholtz Instabi…
Determination of wave vectors using the phase differencing method
Walker, S. N.; Moiseenko, I.
Due to the collisionless nature of space plasmas, plasma waves play an important role in the redistribution of energy between the various particle populations in many regions of geospace. In order to fully comprehend such mechanisms it is necessary to characterise the nature of the waves present. This involves the determination of properties such …