Search Publications

Predictive model of magnetosheath plasma flow and its validation against Cluster and THEMIS data
DOI: 10.5194/angeo-30-973-2012 Bibcode: 2012AnGeo..30..973S

Escoubet, C. P.; Soucek, J.

An analytical model of magnetosheath plasma flow is described and compared with a large dataset of magnetosheath ion flow velocity measurements from Cluster and THEMIS spacecraft. The model is based on previous works by Kobel and Flückiger (1994) and Génot et al. (2011) and has been modified to overcome the restrictions of these models on the shap…

2012 Annales Geophysicae
Cluster 23
Polar cap arcs from the magnetosphere to the ionosphere: kinetic modelling and observations by Cluster and TIMED
DOI: 10.5194/angeo-30-283-2012 Bibcode: 2012AnGeo..30..283M

Lointier, G.; Simon Wedlund, C.; Trotignon, J. -G. +4 more

On 1 April 2004 the GUVI imager onboard the TIMED spacecraft spots an isolated and elongated polar cap arc. About 20 min later, the Cluster satellites detect an isolated upflowing ion beam above the polar cap. Cluster observations show that the ions are accelerated upward by a quasi-stationary electric field. The field-aligned potential drop is es…

2012 Annales Geophysicae
Cluster 17
Electron cross talk and asymmetric electron distributions near the Earth's bowshock
DOI: 10.5194/angeo-30-503-2012 Bibcode: 2012AnGeo..30..503M

Schwartz, S. J.; Auster, U.; Mitchell, J. J.

Electron distributions in the magnetosheath display a number of far from equilibrium features. It has been suggested that one factor influencing these distributions may be the large distances separating locations at which electrons with different energies and pitch angles must cross the bowshock in order to reach a given point in the magnetosheath…

2012 Annales Geophysicae
Cluster 14
Magnetic field amplification in electron phase-space holes and related effects
DOI: 10.5194/angeo-30-711-2012 Bibcode: 2012AnGeo..30..711T

Baumjohann, W.; Treumann, R. A.

Three-dimensional electron phase-space holes are shown to have positive charges on the plasma background, which produce a radial electric field and force the trapped electron component into an azimuthal drift. In this way electron holes generate magnetic fields in the hole. We solve the cylindrical hole model exactly for the hole charge, electric …

2012 Annales Geophysicae
Cluster 14
On the problem of Plasma Sheet Boundary Layer identification from plasma moments in Earth's magnetotail
DOI: 10.5194/angeo-30-1331-2012 Bibcode: 2012AnGeo..30.1331G

Sauvaud, J. -A.; Grigorenko, E. E.; Koleva, R.

The problem of identification of the interface region between the lobe and the Plasma Sheet (PS) - the Plasma Sheet Boundary Layer (PSBL) - using ion moments and magnetic field data often arises in works devoted to statistical studies of various PSBL phenomena. Our experience in the identification of this region based on the analysis of ion veloci…

2012 Annales Geophysicae
Cluster 13
Overlapping ion structures in the mid-altitude cusp under northward IMF: signature of dual lobe reconnection?
DOI: 10.5194/angeo-30-489-2012 Bibcode: 2012AnGeo..30..489P

Berchem, J.; Escoubet, C. P.; Pitout, F. +2 more

On some rare occasions, data from the Cluster Ion Spectrometer (CIS) in the mid-altitude cusp reveal overlapping ion populations under northward interplanetary magnetic field (IMF). While the poleward part of the cusp exhibits the expected reverse dispersion due to lobe reconnection, its equatorward part shows a second ion population at higher-ene…

2012 Annales Geophysicae
Cluster 11
Magnetopause energy transfer dependence on the interplanetary magnetic field and the Earth's magnetic dipole axis orientation
DOI: 10.5194/angeo-30-515-2012 Bibcode: 2012AnGeo..30..515P

Fear, R. C.; Palmroth, M.; Honkonen, I.

We examine the spatial variation of magnetospheric energy transfer using a global magnetohydrodynamic (MHD) simulation (GUMICS-4) and a large data set of flux transfer events (FTEs) observed by the Cluster spacecraft. Our main purpose is to investigate whether it is possible to validate previous results on the spatial energy transfer variation fro…

2012 Annales Geophysicae
Cluster 10
Electron scale structures of thin current sheets in magnetic reconnection
DOI: 10.5194/angeo-30-661-2012 Bibcode: 2012AnGeo..30..661J

Malova, H. V.; Zelenyi, L. M.; Jain, N. +1 more

An electron-magnetohydrodynamic model is used to simulate the structure of an electron scale current sheet during early phase of collisionless magnetic reconnection. The current sheet develops structures, viz. bifurcated, filamented and triple-peak structures at different locations in the current sheet. The reversal of the net out-of-plane electri…

2012 Annales Geophysicae
Cluster 10
3-D mesoscale MHD simulations of magnetospheric cusp-like configurations: cusp diamagnetic cavities and boundary structure
DOI: 10.5194/angeo-30-325-2012 Bibcode: 2012AnGeo..30..325A

Adamson, E.; Otto, A.; Nykyri, K.

We present results from mesoscale simulations of the magnetospheric cusp region for both strongly northward and strongly southward interplanetary magnetic field (IMF). Simulation results indicate an extended region of depressed magnetic field and strongly enhanced plasma β which exhibits a strong dependence on IMF orientation. These structures cor…

2012 Annales Geophysicae
Cluster 10
Study of the applicability of the curlometer technique with the four Cluster spacecraft in regions close to Earth
DOI: 10.5194/angeo-30-597-2012 Bibcode: 2012AnGeo..30..597G

Dandouras, I.; Lucek, E.; Grimald, S. +1 more

Knowledge of the inner magnetospheric current system (intensity, boundaries, evolution) is one of the key elements for the understanding of the whole magnetospheric current system. In particular, the calculation of the current density and the study of the changes in the ring current is an active field of research as it is a good proxy for the magn…

2012 Annales Geophysicae
Cluster 10