Alternating bursts of low energy ions and electrons near the substorm onset

Kozelova, T. V.; Lazutin, L. L.; Kozelov, B. V.; Meredith, Nigel P.; Danielides, Michael

doi:10.5194/angeo-24-1957-2006

Cited by 6 publications

(6 citation statements)

References 45 publications

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“…After 18:34 UT (moment “1”), we can observe the following: (i) the injection of fresh high‐energy ions (81 –157 keV) ( population “3”) occurs simultaneously with the sharp drop of pressure of the low‐energy (< 29 keV) ions and (ii) the anticorrelation of the high‐energy ions and electron fluxes appears. The last is usually observed during passage across the WTS and can be associated with the interchange instability [ Roux , ; Roux et al ., ; Kozelova et al ., , ]. The substorm onset is a source of these fresh westward drifting energetic ions, and it locates near and eastward of the THEMIS‐C.…”

Section: Observations During the Substorm On 6 January 2008mentioning

confidence: 99%

“…This new electron flux may be a signature of a coupling of the shear flow and KH instabilities. In the linear stage, this coupling may generate vortex‐like structures [ Voronkov et al ., , ] (see for details). The oscillations with a similar period of 40–65 s often appear during the growth phase near r = 6.6 R E before substorm onset [ Roux et al ., ; Holter et al ., ; Erickson et al ., ; Kozelova et al ., ]. The second state of plasma was observed after the moment “1” in the region of lower pressure of the low‐energy (< 29 keV) ions with the highly stretched magnetic field lines. The system jumps to this state at the nonlinear stage of development of the instability (ballooning, see for details) with growth timescale ~ 10 s. The sharp spatial boundary between the inner magnetosphere and the plasma sheet is formed during the substorm onset and delineates the transition from dipolar to taillike magnetic field configuration with an estimated magnetic field jump of ~ 8 nT. This region was observed when Ey was negative.…”

Section: Dynamics Of Field and Currents In The Magnetospherementioning

confidence: 99%

“…The oscillations with a similar period of 40–65 s often appear during the growth phase near r = 6.6 R E before substorm onset [ Roux et al ., ; Holter et al ., ; Erickson et al ., ; Kozelova et al ., ].…”

Section: Dynamics Of Field and Currents In The Magnetospherementioning

confidence: 99%

“…Another idea invokes a kinetic CD process in the near‐Earth region during substorm onset, when substorm dipolarization occurs without significant plasma flow [ Mitchell et al ., ; Lui et al ., ; Ohtani et al ., ]. The current disruption is generally attributed to various forms of ballooning instability [ Roux et al ., ; Ohtani et al ., ; Holter et al ., ; Maynard et al ., ; Erickson et al ., ; Kozelova et al ., ; Liu et al ., ], and the cross‐field current instability [ Lui , ; Lui et al ., ]. However, the instability type dominating the onset process is still indeterminate, and it is not clear how the instability onset location is tied to field lines threading an auroral arc.…”

Section: Introductionmentioning

confidence: 99%

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Substorm‐associated explosive magnetic field stretching near the earthward edge of the plasma sheet

Kozelova

Kozelov

2013

JGR Space Physics

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[1] We report a detailed analysis of explosive local magnetic field line stretching just before dipolarization observed by one of Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites during the pseudo-breakup followed by local substorm of 6 January 2008. At the end of the substorm growth phase, this satellite (THEMIS-C) was located at r~6.3 R E near the convection boundary of 10 keV electrons. Penetration of the hot electron plasma sheet to the region of trapped energetic ions was a precondition for the substorm onset in the premidnight sector. Observed oscillations of fields and particles with period 50-60 s are consistent with the ballooning mode in the near-Earth magnetotail and with the near-Earth initiation current disruption model. Basing on the simple line-current model, the explosive stretching and following dipolarization observed by THEMIS-C satellite are interpreted as a manifestation of the magnetospheric generator of the 3-D meridional current system with the driving electric field in the meridional direction during nonlinear growth of ballooning instability when non-MHD processes are also turning on.Citation: Kozelova, T. V., and B. V. Kozelov (2013), Substorm-associated explosive magnetic field stretching near the earthward edge of the plasma sheet,

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Section: Observations During the Substorm On 6 January 2008mentioning

confidence: 99%

Section: Dynamics Of Field and Currents In The Magnetospherementioning

confidence: 99%

Section: Dynamics Of Field and Currents In The Magnetospherementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Substorm‐associated explosive magnetic field stretching near the earthward edge of the plasma sheet

Kozelova

Kozelov

2013

JGR Space Physics

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“…Occurrence of a storm, even a moderate one, can be not directly related to the occurrence of the surface charging. The electron flux at the keV energies is largely determined by convective (Korth et al 1999;Elkington et al 2004;Miyoshi et al 2006;Kurita et al 2011;) and substorm-associated (Vakulin et al 1988;Grafodatskiy et al 1987;Degtyarev et al 1990;Fok et al 2001a;Khazanov et al 2004;Kozelova et al 2006;Ganushkina et al 2013;Turner et al 2015) electric fields. Since it varies on short time scales, it is not possible to average the keV electron fluxes over an orbit/day/hour as it can be done for higher energies, like MeVs.…”

Section: Ring Current Electrons and Effects On Satellitesmentioning

confidence: 99%

Space Weather Effects Produced by the Ring Current Particles

2017

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One of the definitions of space weather describes it as the time-varying space environment that may be hazardous to technological systems in space and/or on the ground and/or endanger human health or life. The ring current has its contributions to space weather effects, both in terms of particles, ions and electrons, which constitute it, and magnetic and electric fields produced and modified by it at the ground and in space. We address the main aspects of the space weather effects from the ring current starting with brief review of ring current discovery and physical processes and the Dst-index and predictions of the ring current and storm occurrence based on it. Special attention is paid to the effects on satellites produced by the ring current electrons. The ring current is responsible for several processes in the other inner magnetosphere populations, such as the plasmasphere and radiation belts which is also described. Finally, we discuss the ring current influence on the ionosphere and the generation of geomagnetically induced currents (GIC).

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Low‐energy electrons (5–50 keV) in the inner magnetosphere

et al. 2014

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[1] Transport and acceleration of the 5-50 keV electrons from the plasma sheet to geostationary orbit were investigated. These electrons constitute the low-energy part of the seed population for the high-energy MeV particles in the radiation belts and are responsible for surface charging. We modeled one nonstorm event on 24-30 November 2011, when the presence of isolated substorms was seen in the AE index. We used the Inner Magnetosphere Particle Transport and Acceleration Model (IMPTAM) with the boundary at 10 R E with moment values for the electrons in the plasma sheet. The output of the IMPTAM modeling was compared to the observed electron fluxes in 10 energy channels (from 5 to 50 keV) measured on board the AMC 12 geostationary spacecraft by the Compact Environmental Anomaly Sensor II with electrostatic analyzer instrument. The behavior of the fluxes depends on the electron energy. The IMPTAM model, driven by the observed parameters such as Interplanetary Magnetic Field (IMF) B y and B z , solar wind velocity, number density, dynamic pressure, and the Dst index, was not able to reproduce the observed peaks in the electron fluxes when no significant variations are present in those parameters. We launched several substorm-associated electromagnetic pulses at the substorm onsets during the modeled period. The observed increases in the fluxes can be captured by IMPTAM when substorm-associated electromagnetic fields are taken into account. Modifications of the pulse front velocity and arrival time are needed to exactly match the observed enhancements.

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Alternating bursts of low energy ions and electrons near the substorm onset

Cited by 6 publications

References 45 publications

Substorm‐associated explosive magnetic field stretching near the earthward edge of the plasma sheet

Substorm‐associated explosive magnetic field stretching near the earthward edge of the plasma sheet

Space Weather Effects Produced by the Ring Current Particles

Low‐energy electrons (5–50 keV) in the inner magnetosphere

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