Ion and electron heating in the earth's bow shock region

Revathy, P.; Lakhina, G. S.

doi:10.1017/s002237780002050x

Cited by 11 publications

(5 citation statements)

References 18 publications

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“…The ions are heated principally in the perpendicular direction, while the electrons are heated mainly parallel to the magnetic field and have a flattop distribution. The large ion heating that occurs in the zero beta limit was first shown by Revathy and Lakina [1977]. At higher beta, the…”

Section: Applicationsmentioning

confidence: 87%

Plasma heating at collisionless shocks due to the kinetic cross‐field streaming instability

Winske

Tanaka²,

et al. 1985

J. Geophys. Res.

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Heating at collisionless shocks due to the kinetic cross‐field streaming instability, which is the finite beta (ratio of plasma to magnetic pressure) extension of the modified two stream instability, is studied. Heating rates are derived from quasi‐linear theory and compared with results from particle simulations to show that electron heating relative to ion heating and heating parallel to the magnetic field relative to perpendicular heating for both the electrons and ions increase with beta. The simulations suggest that electron dynamics determine the saturation level of the instability, which is manifested by the formation of a flattop electron distribution parallel to the magnetic field. As a result, both the saturation levels of the fluctuations and the heating rates decrease sharply with beta. Applications of these results to plasma heating in simulations of shocks and the earth's bow shock are described.

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Section: Applicationsmentioning

confidence: 87%

Plasma heating at collisionless shocks due to the kinetic cross‐field streaming instability

Winske

Tanaka²,

et al. 1985

J. Geophys. Res.

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“…The anomalous collision frequency due to plasma instabilities driven essentially by field-aligned currents is typically a fraction of the ion cyclotron frequency, i.e., van "" •p [Dum and Dupree, 1970;Treumann et at., 1991], whereas it can be substantially higher for the case of perpendicular current-driven instabilities [LaBette and Treumann, 1988;Thorne and Tsurutani, 1991]. Anomalous collision frequencies can be used to estimate the cross-field diffusion coefficient [Ichimaru, 1973]: The dielectric constant, e(w, k), for the lower hybrid waves is given by [Lakhina and Sen, 1973;Davidson, 1978;Revathy and Lakhina, 1977] -+ = 0, (8)…”

Section: Anomalous Diffusion From Plasma Instabilitiesmentioning

confidence: 99%

“…At the JBL, B0 • 5 nT, and assuming a proton kinetic energy of I keV, we get from (3) the maximum diffusion rate, Dmax -105 km 2 s -1. Then taking the magnetic wave power of • 10 -1 nT 2 at resonance, the cross-field diffusion as calculated from (2) Lakhina, 1977;Papadopoulos, 1979]. Like the lower hybrid drift instability, this instability also leads to anomalous resistivity and cross-field particle diffusion.…”

Section: Cross-field Diffusion and Boundary Layer Formationmentioning

confidence: 99%

“Broadband” plasma waves in the boundary layers

Lakhina¹,

Tsurutani²,

Kojima³

et al. 2000

J. Geophys. Res.

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Abstract. Boundary layers are commonly encountered in space and astrophysical plasmas. For example, interaction of solar wind plasma with the planets and comets produces magnetopause and cometopause boundary layers, respectively. Generally, the boundary layers are formed when plasmas with different characteristics interact with each other. The plasma sheet boundary layer in the Earth's magnetotail is formed owing to the interaction of hot dense plasma in the plasma sheet region with the rarefied plasma of the lobe region. Boundary layers are the site where energy and momentum are exchanged between two distinct plasmas. Boundary layers occurring in space plasmas can support a wide spectrum of plasma waves spanning a frequency range of a few mHz to 100 kHz and beyond. The purpose of this review is to describe the main characteristics and the possible generation mechanisms of the broadband plasma waves (with frequencies of • 1 Hz) observed in the Earth's magnetopause boundary layer, the Jovian magnetopause boundary layer, the plasma sheet boundary layer, and the Earth's polar cap boundary layer. The rapid pitch angle scattering of energetic particles via cyclotron resonant interactions with the waves can provide suificient precipitated energy flux to the ionosphere to create the dayside aurora at Earth and a weak high-latitude auroral ring at Jupiter. In general, the broadband plasma waves may play an important part i_n the processes of local heating/acceleration of the boundary layer plasma. Recent exciting high time resolution results on the broadband plasma waves coming from Geotail, Polar, and FAST will be discussed.

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“…Some of the important generation models are based on the lower hybrid drift instability (LHDI) driven essentially by the density gradients [36][37][38], field-aligned current driven instabilities, like ion-acoustic instability [39], and ion cyclotron instability [40], ion beam instabilities [41][42][43][44][45][46][47], electron beam instabilities [34,35,[48][49][50][51], loss cone instabilities generated by the electron loss distributions [52], and velocity shear and current convective instabilities [27,29,30,[53][54][55][56][57]. The mechanism of current convective instability demands thickness of the magnetopause current layer, Ä, to be very narrow such that Ä AE , where AE Ô ( and Ô are the speed of light and the electron plasma frequency, respectively) is the electron skin depth.…”

Section: Generation Mechanismsmentioning

confidence: 99%

Sun-Earth connection: Boundary layer waves and auroras

et al. 2000

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Boundary layers are the sites where energy and momentum are exchanged between two distinct plasmas. Boundary layers occurring in space plasmas can support a wide spectrum of plasma waves spanning a frequency range of a few mHz to 100 kHz and beyond. The main characteristics of the broadband plasma waves (with frequencies 1 Hz) observed in the magnetopause, polar cap, and plasma sheet boundary layers are described. The rapid pitch angle scattering of energetic particles via cyclotron resonant interactions with the waves can provide sufficient precipitated energy flux to the ionosphere to create the diffused auroral oval. The broadband plasma waves may also play an important role in the processes of local heating/acceleration of the boundary layer plasma.

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Ion and electron heating in the earth's bow shock region

Cited by 11 publications

References 18 publications

Plasma heating at collisionless shocks due to the kinetic cross‐field streaming instability

Plasma heating at collisionless shocks due to the kinetic cross‐field streaming instability

“Broadband” plasma waves in the boundary layers

Sun-Earth connection: Boundary layer waves and auroras

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