Multi-spacecraft observation of plasma dipolarization/injection in the inner magnetosphere
S. Apatenkov,V. A. Sergeev,Marina Kubyshkina,Rumi Nakamura,Wolfgang Baumjohann,Andrei Runov,I. Alexeev,Andrew Fazakerley,Harald U. Frey,S. Mühlbachler,P. W. Daly,J. A. Sauvaud,Natalia Ganushkina,Tuija Pulkkinen,Geoffrey D. Reeves,Yu. V. Khotyaintsev +15 more
TLDR
In this article, the authors investigated the origin of the energetic particle injections into the inner magnetosphere using a favorable constellation of four Cluster (near perigee), LANL and Geotail spacecraft.Abstract:
. Addressing the origin of the energetic particle injections into the inner magnetosphere, we investigate the 23 February 2004 substorm using a favorable constellation of four Cluster (near perigee), LANL and Geotail spacecraft. Both an energy-dispersed and a dispersionless injection were observed by Cluster crossing the plasma sheet horn, which mapped to 9–12 RE in the equatorial plane close to the midnight meridian. Two associated narrow equatorward auroral tongues/streamers propagating from the oval poleward boundary could be discerned in the global images obtained by IMAGE/WIC. As compared to the energy-dispersed event, the dispersionless injection front has important distinctions consequently repeated at 4 spacecraft: a simultaneous increase in electron fluxes at energies ~1..300 keV, ~25 nT increase in BZ and a local increase by a factor 1.5–1.7 in plasma pressure. The injected plasma was primarily of solar wind origin. We evaluated the change in the injected flux tube configuration during the dipolarization by fitting flux increases observed by the PEACE and RAPID instruments, assuming adiabatic heating and the Liouville theorem. Mapping the locations of the injection front detected by the four spacecraft to the equatorial plane, we estimated the injection front thickness to be ~1 RE and the earthward propagation speed to be ~200–400 km/s (at 9–12 RE). Based on observed injection properties, we suggest that it is the underpopulated flux tubes (bubbles with enhanced magnetic field and sharp inner front propagating earthward), which accelerate and transport particles into the strong-field dipolar region.read more
Citations
More filters
Journal ArticleDOI
Fermi and betatron acceleration of suprathermal electrons behind dipolarization fronts
TL;DR: Two dipolarization front structures observed by Cluster in the Earth midtail region (X(GSM) approximate to -15 R(E)), showing respectively the feature of Fermi and betatron acceleration of sup...
Journal ArticleDOI
Particle Acceleration in the Magnetotail and Aurora
Joachim Birn,Joachim Birn,Anton Artemyev,Daniel N. Baker,Marius Echim,Masahiro Hoshino,Lev Zelenyi +6 more
TL;DR: In this article, the acceleration processes in the magnetotail and the processes that enhance particle precipitation from the tail into the ionosphere through electric fields in the auroral acceleration region, generating or intensifying discrete auroral arcs are discussed.
Journal ArticleDOI
THEMIS observation of multiple dipolarization fronts and associated wave characteristics in the near-Earth magnetotail
Meng Zhou,Meng Zhou,Maha Ashour-Abdalla,Xiaohua Deng,Xiaohua Deng,David Schriver,Mostafa El-Alaoui,Y. Pang,Y. Pang +8 more
TL;DR: In this article, the dipolarization fronts were observed at the leading edge of earthward propagating plasma bubbles, which were associated with large wave fluctuations extending from below the lower hybrid frequency to above the electron cyclotron frequency.
Journal ArticleDOI
Oblique Whistler-Mode Waves in the Earth’s Inner Magnetosphere: Energy Distribution, Origins, and Role in Radiation Belt Dynamics
Anton Artemyev,Anton Artemyev,Oleksiy Agapitov,Didier Mourenas,Vladimir Krasnoselskikh,Vitalii Shastun,F. S. Mozer +6 more
TL;DR: In this paper, the statistics of occurrences and intensity of oblique chorus waves in the region of the outer radiation belt, comprised between the plasmapause and geostationary orbit, and discuss how their actual distribution may be explained by a combination of linear and non-linear generation, propagation, and damping processes.
Journal ArticleDOI
Particle acceleration in dipolarization events
TL;DR: In this paper, the acceleration of test particles (protons and electrons) to suprathermal energies was investigated using the electromagnetic fields of a recent MHD simulation of magnetotail reconnection, flow bursts and dipolarization, confirming and extending earlier results on acceleration mechanisms and sources.
References
More filters
Journal ArticleDOI
A magnetospheric magnetic field model with a warped tail current sheet
TL;DR: In this article, an improved quantitative representation of the magnetic field in the geomagnetosphere is developed, taking into account the effect of warping the tail current sheet in two dimensions due to the geodipole tilt, as well as spatial variations of the current sheet thickness along the Sun-Earth and dawn-dusk directions.
Journal ArticleDOI
The Cluster Magnetic Field Investigation: overview of in-flight performance and initial results
A. Balogh,Chris Carr,Mario H. Acuña,M. W. Dunlop,T. Beek,Patrick Brown,Karl-Heinz Fornacon,E. Georgescu,Karl-Heinz Glassmeier,J. Harris,G. Musmann,T. Oddy,Konrad Schwingenschuh +12 more
TL;DR: In this paper, the authors present an overview of the instrumentation used to measure the magnetic field on the four Cluster spacecraft and an overview the performance of the operational modes used in flight.
Journal ArticleDOI
Modeling the Earth's magnetospheric magnetic field confined within a realistic magnetopause
TL;DR: In this paper, the authors describe a new approach to the problem of fitting the magnetosphereic magnetic field to spacecraft data, based on fits to a large number of observed crossing (allowing a parametrization by the solar wind pressure).
Book ChapterDOI
Peace: a plasma electron and current experiment
A. D. Johnstone,C. Alsop,S. Burge,P. J. Carter,Andrew J. Coates,A. J. Coker,Andrew Fazakerley,Manuel Grande,R. A. Gowen,C. Gurgiolo,B. K. Hancock,B. T. Narheim,Alun Preece,P. H. Sheather,J. D. Winningham,R. D. Woodliffe +15 more
TL;DR: In this paper, an electron analyser was used to measure the three-dimensional velocity distribution of electrons in the energy range from 0.59 eV to 26.4 keV on the four spacecraft of the Cluster mission.
Journal ArticleDOI
Detection of localized, plasma‐depleted flux tubes or bubbles in the midtail plasma sheet
TL;DR: In this article, the authors present multi-instrument observations from the ISEE1 and ISEE 2 spacecraft to argue that when the plasma sheet becomes thick and close to its equilibrium state, the plasma and magnetic field signatures of high-speed flow events are consistent with the theoretically predicted signatures of plasma-depleted flux tubes or "bubbles".