Development of parallel electric fields at the plasma sheet boundary layer

Lysak, R. L.; Song, Yan

doi:10.1029/2010ja016424

Cited by 39 publications

(36 citation statements)

References 103 publications

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“…The parallel displacement current is ignored in the runs shown. However, in principle it should be present and can be included for cases where parallel electric fields are expected to develop [ Song and Lysak , , ; Lysak and Song , , ]. Ohmic currents in the ionosphere are included on the right‐hand side of Ampere's law.…”

Section: Model Descriptionmentioning

confidence: 99%

Propagation of Pi2 pulsations in a dipole model of the magnetosphere

et al. 2015

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Localized fast flows that impinge on the inner magnetosphere from the plasma sheet are observed to oscillate on time scales of minutes. The compression ahead of these flows will launch fast mode waves, while the velocity shears at the edges of these flows directly excite shear Alfvén waves. These waves, which are coupled by gradients in the Alfvén speed, have been suggested as a source for the Pi1 and Pi2 waves that are observed at both high and low latitudes in the ionosphere. A new three-dimensional simulation of the propagation of ULF waves in the dipolar region of the magnetosphere has been developed to study these coupled wave modes. This model includes a height-resolved ionospheric conductivity so that ionospheric fields can be more realistically determined, as well as a direct calculation of ground magnetic fields to compare with ground magnetometers using an inductive ionosphere model. Results from this model show that a plasmaspheric resonance can be set up by waves with periods about 1 min and that field line resonances can be excited both inside and outside the plasmasphere. The use of the inductive ionosphere model leads to the conclusion that even a uniform Hall conductivity can break the dawn-dusk symmetry of the convection pattern. Waves from a source at 10 Earth radii reach the ionosphere with time delays between high and low latitudes of tens of seconds, with implications for the timing of substorm phenomena observed by spacecraft and by ground magnetometers and radars.

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Section: Model Descriptionmentioning

confidence: 99%

Propagation of Pi2 pulsations in a dipole model of the magnetosphere

et al. 2015

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“…Finally, instabilities generating KAWs in plasma with transverse density modulations have been considered by Wu and Chen []. Similar ideas involving dissipative mechanisms related to interaction of Alfvén waves or KAWs and phase mixing have been examined in the context of the magnetospheric plasma sheet [ Lysak and Song , ] and in coronal loops [ Ofman and Aschwanden , ]. It has been shown that ion‐scale shear Alfvén waves can be excited by ion beams in the solar wind [ Hellinger and Trávníček , , ], and these can contribute to the formation of KAWs [ Nariyuki et al , ].…”

Section: Introductionmentioning

confidence: 99%

From Alfvén waves to kinetic Alfvén waves in an inhomogeneous equilibrium structure

et al. 2016

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Kinetic Alfvén waves are believed to primary form fluctuations in a hydromagnetic turbulence at scales of the order of the ion inertial length. We study a model where an initial Alfvén wave propagates inside an equilibrium structure which is inhomogeneous in the direction perpendicular to the equilibrium magnetic field. In a previous paper this situation has been considered in a particular configuration where the initial wave vector is parallel to the magnetic field and the wave is polarized perpendicular to the inhomogeneity direction. Here we consider other configurations, with a different polarization and possible initial oblique propagation. We employ numerical simulations, using both a Hall‐magnetohydrodynamics and a Hybrid Vlasov‐Maxwell model. Results show that in all the considered cases the time evolution leads to the formation of kinetic Alfvén waves within the inhomogeneity regions, which are identified by a comparison with analytical linear theory results. Then, in this context the formation of kinetic Alfvén waves seems to be a general phenomenon which could be also extended to more complex situations, like turbulence. Kinetic simulations show that kinetic Alfvén waves modify the ion distribution function, generating temperature anisotropy of both parallel and perpendicular to the local magnetic field as well as particle beams aligned along the local magnetic field. These results could be relevant both in the solar corona and in large‐scale structures of the solar wind, where Alfvénic fluctuations are present along with large‐scale inhomogeneities.

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“…In addition to the broadening effect due to the perpendicular group velocity of the kinetic Alfven wave, phase mixing, which is due to the inhomogeneity of plasma perpendicular to the ambient magnetic field [ Lysak and Song , , ], and nonlinear effects, particularly the convective nonlinearity in the perpendicular equation of motion [e.g., Seyler , , ; Chaston and Seki , ], can narrow the scale of these Alfven waves. These effects need to be carefully investigated in future researches that expand our 1‐D kinetic model to a multidimensional one.…”

Section: Discussionmentioning

confidence: 99%

Coupling of electrons and inertial Alfven waves in the topside ionosphere

et al. 2013

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[1] A one-dimensional kinetic model is constructed to simulate the electron acceleration by inertial Alfven waves. The electrons are divided into cold and hot electrons and treated separately. Cold components are described by the fluid equation and hot ones by the Vlasov equation, both carrying field-aligned currents. Intense variation of Alfven speed has been introduced by inclusion of cold electrons. The model results show that the exponential decrease of the plasma density plays a key role, which leads to the sharp gradient of both Alfven velocity and electron inertial length. When Alfven waves encounter this sharp gradient at lower altitudes, the electrons accelerated by the waves become super-Alfvenic, and the width of burst structures becomes much wider than the electron inertial length. Consequently, the background electrons carry the oppositely field-aligned current due to plasma oscillation. It is demonstrated that the current carried by the electrons exceeding the wavefront is balanced by the reverse current carried by background electrons. This mechanism can be used to reasonably explain observations of the electron bursts accompanied by little net field-aligned current. Furthermore, our simulation indicates another type of Alfven wave reflection due to mirror force and wave-particle interaction.

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Development of parallel electric fields at the plasma sheet boundary layer

Cited by 39 publications

References 103 publications

Propagation of Pi2 pulsations in a dipole model of the magnetosphere

Propagation of Pi2 pulsations in a dipole model of the magnetosphere

From Alfvén waves to kinetic Alfvén waves in an inhomogeneous equilibrium structure

Coupling of electrons and inertial Alfven waves in the topside ionosphere

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