Hydrodynamical equations for thermal electrons taking into account their scattering on ion-cyclotron waves in the outer plasmasphere of the earth

Konikov, Yu. V.; Gorbachev, O. A.; Khazanov, G. V.; Chernov, A. A.

doi:10.1016/0032-0633(89)90011-1

Cited by 20 publications

(8 citation statements)

References 34 publications

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“…Observational and modeling studies addressing the role of ion cyclotron waves in the energetics of the inner magnetosphere and underlying subauroral ionosphere continue. Konikov et al [1989] have calculated energy exchange from a modeled proton ring current to plasmaspheric electrons via ICWs and estimate the resultant heating rates to the underlying ionospheric electrons. These heating rates reached values sufficient to produce observable SAR arcs.…”

Section: Possible Role Of Plasma Wavesmentioning

confidence: 99%

High‐altitude energy source(s) for stable auroral red arcs

Kozyra¹,

Nagy²,

Slater³

1997

Reviews of Geophysics

145

170

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Abstract. Stable auroral red (SAR) arcs have been viewed across the midlatitude night sky with interest since their discovery in 1956. This relatively late discovery (compared to the poleward aurora) is a direct consequence of the subvisual levels of the delicate and diffuse light that makes up the SAR arc. Except in rare instances when the emissions actually crossover the threshold to visible levels, optical instruments are required to register their presence and document their morphology and occurrence frequency. SAR arcs are seen as relatively featureless, slowly changing bands of red light that can extend across the entire night sky. Early observations from the ground and from satellites established the relationship between SAR arcs and magnetic disturbances in near-Earth space involving the ring current (a population of high-energy ions trapped in the Earth's magnetic field). The long-lived, soft, red glow of SAR arcs reflects the slow energy loss from the ring current ions as they bounce back and forth in the Earth's confining field geometry, but the exact sequence of physical processes that feed a portion of the ring current energy to the SAR arc region is a matter of continuing INTRODUCTIONGlowing gases in the Earth's upper atmosphere provide dynamic tracers of the pathways energy takes from high to low altitudes as the Earth interacts with the near-space environment. The behaviors of these glowing regions in space and time offer definite clues to the high-altitude energy source, to the energy transport pathways, and to the manner in which the atmosphere adjusts to the additional energy influx. In general, atmospheric emissions are the end result of a series of physical processes that connect the Earth's atmosphere to the external near-space environment. The understanding of these natural systems has undergone major advances over the last decade, as measurements, by spacecraft within and above the emission regions and observations from ground-based optical and radar instruments, provide a fertile proving ground for theoretical models. In this review, recent developments in our understanding of the stable auroral red (SAR) arc system are described. Over the last decade, spacecraft missions and accumulating long-term ground-based observations of SAR arcs have led to revised views on their formation and variability. SAR arcs are glowing red emissions that appear at high altitudes in the midlatitude night sky, extending in diffuse, sometimes continuous, bands from the dusk to the dawn terminators. They appear simultaneously in both the northern and southern hemispheres. The dayside portion of the SAR arcs is difficult to detect above the much stronger background dayglow emissions. SAR arcs occur on approximately 10-12% of nights throughout the solar cycle, with the preponderance being near the period of maximum solar activity. However, the

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Section: Possible Role Of Plasma Wavesmentioning

confidence: 99%

High‐altitude energy source(s) for stable auroral red arcs

Kozyra¹,

Nagy²,

Slater³

1997

Reviews of Geophysics

145

170

View full text Add to dashboard Cite

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“…The model was based on a generalized 16-moment system of transport equations. The 16-moment system, with the effects of thermal electrons and their scattering on ion-cyclotron waves, was studied by Konikov et al [1989] and Konikov [1990].…”

Section: Wave-particle Interactions and Energizationmentioning

confidence: 99%

The polar wind

Ganguli¹

1996

Reviews of Geophysics

131

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The polar wind is an ambipolar outflow of thermal plasma from the terrestrial ionosphere at high latitudes to the magnetosphere along geomagnetic field lines. The polar wind plasma consists mainly of H+, He+, and O+ ions and electrons. Although it was initially believed that O+ ions play a major role only at low altitudes, it is now clear from observations that relatively large amounts of suprathermal and energetic O+ ions are present in the polar magnetosphere. Recently, thermal O+ outflow has been observed at altitudes of 5000–10,000 km together with H+ and He+ ions. The polar wind undergoes four major transitions as it flows from the ionosphere to the magnetosphere: (1) from chemical to diffusion dominance, (2) from subsonic to supersonic flow, (3) from collision‐dominated to collisionless regimes, and (4) from heavy to light ion composition. The collisions are important up to about 2500 km, after which the ions and electrons exhibit temperature anisotropies. The direction of the anisotropy varies with geophysical conditions. The polar wind outflow varies with season, solar cycle, and geomagnetic activity. The O+ flux exhibits a summer maximum, while the H+ flux reaches a maximum in the spring. The He+ flux increases by a factor of 10 from summer to winter. At both magnetically quiet and active times the integrated H+ ion flux is largest in the noon sector and smallest in the midnight sector. The integrated upward H+ ion flux exhibits a positive correlation with the interplanetary magnetic field. In the sunlit polar cap the photoelectrons can increase the ambipolar electric field, which in turn increases the polar wind ion outflow velocities. The outflowing polar wind plasma flux tubes also convect across the polar cap. When the flux tubes cross the cusp and nocturnal auroral regions, the plasma can be heated and become unstable. Similar mixing of hot magnetospheric plasma with cold polar wind may result in instabilities. A number of free energy sources in the polar wind, including temperature anisotropy, relative drift between species, and spatial inhomogeneities, feed various fluid and kinetic instabilites. The instabilities can produce plasma energization and cross‐field transport, which modify the large‐scale polar wind outflow.

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“…In developing a mathematical model to describe plasma transport in the magnetosphere-ionosphere system that accounts for the active wave processes which occur there, we must develop a general scheme to include an analysis of the dispersion characteristics of the medium in order to choose suitable wave modes, a wave-particle interaction mechanism, and a system of hydrodynamical equations governing ma6roscopic plasma parameters which properly accounts for the presence of wave-particle interactions. One basis for this scheme's development has been described elsewhere [Khazanov and Chernov, 1988;Konikov et al, 1989; Chernov et al, 1990;Gamayunov et al, 1991Gamayunov et al, , 1992Gorbachev et al, 1992].…”

Section: and References Therein]mentioning

confidence: 99%

“…Ganguli and Palmadesso [1987, 1988], Singh [1988], Singh and Torr [1990], Brown et al [1991, 1995], and Lin et al [1992, 1994] took into account effects from the low-frequency (LF) electrostatic turbulence, and they demonstrated that wave-particle interactions lead to significant effects on the evolution of the core plasma distribution functions.In developing a mathematical model to describe plasma transport in the magnetosphere-ionosphere system that accounts for the active wave processes which occur there, we must develop a general scheme to include an analysis of the dispersion characteristics of the medium in order to choose suitable wave modes, a wave-particle interaction mechanism, and a system of hydrodynamical equations governing ma6roscopic plasma parameters which properly accounts for the presence of wave-particle interactions. One basis for this scheme's development has been described elsewhere [Khazanov and Chernov, 1988;Konikov et al, 1989; Chernov et al, 1990;Gamayunov et al, 1991Gamayunov et al, , 1992Gorbachev et al, 1992].When such LF waves are propagating in a plasma, a ponderomotive force is produced, which leads to significant effects in the plasma. Boehm et al [1990] suggested that this ponde.romotive force can be the cause of significant density perturbations in the auroral zone.…”

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confidence: 99%

Lower hybrid oscillations in multicomponent space plasmas subjected to ion cyclotron waves

Khazanov¹,

Krivorutsky²,

Moore³

et al. 1997

J. Geophys. Res.

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Abstract. It is found that in multicomponent plasmas subjected to Alfv6n or fast magnetosonic waves, such as are observed in regions of the outer plasmasphere and ring currentplasmapause overlap, lower hybrid oscillations are generated. The addition of a minor heavy ion component to a proton-electron plasma significantly lowers the low-frequen9y electric wave amplitude needed for lower hybrid wave excitation. It is found that the lower hybrid wave energy density level is determined by the nonlinear process of induced scattering by ions and electrons; hydrogen ions in the region of resonant velocities are accelerated; and nonresonant particles are weakly heated due to the induced scattering. For a given example, the ligh.t resonant ions have an energy gain factor of 20, leading to the development of a high-energy tail in the H + distribution function due to low-frequency waves. By interacting with charged particles, the waves influence the behavior of the plasma as a whole, and therefore wave effects must be included in corresponding models. Ganguli and Palmadesso [1987, 1988], Singh [1988], Singh and Torr [1990], Brown et al. [1991, 1995], and Lin et al. [1992, 1994] took into account effects from the low-frequency (LF) electrostatic turbulence, and they demonstrated that wave-particle interactions lead to significant effects on the evolution of the core plasma distribution functions.In developing a mathematical model to describe plasma transport in the magnetosphere-ionosphere system that accounts for the active wave processes which occur there, we must develop a general scheme to include an analysis of the dispersion characteristics of the medium in order to choose suitable wave modes, a wave-particle interaction mechanism, and a system of hydrodynamical equations governing ma6ro-scopic plasma parameters which properly accounts for the presence of wave-particle interactions. One basis for this scheme's development has been described elsewhere Khazanov et al. [1996] assumed that the plasma consists of only electrons and protons and that the LFW electric field is strong enough not only to make the relative proton velocity greater than its thermal velocity, but also to create strong LHW turbulence. From (1), however, it can be seen that the LFW energy density needed for LHW excitation may be lower in the presence of a heavy ion component. Since the magnetosphere and ionosphere have multicomponent plasmas, it can be supposed that LHWs can be excited in such plasmas by LFWs with amplitudes less than that needed for a proton-electron plasma.This leads us to the problem of LFW interaction with a multicomponent plasma due to LHW excitation. In accordance with this problem, we will study the following questions:1 LHW excitation are analyzed, and an estimation of particle

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Hydrodynamical equations for thermal electrons taking into account their scattering on ion-cyclotron waves in the outer plasmasphere of the earth

Cited by 20 publications

References 34 publications

High‐altitude energy source(s) for stable auroral red arcs

High‐altitude energy source(s) for stable auroral red arcs

The polar wind

Lower hybrid oscillations in multicomponent space plasmas subjected to ion cyclotron waves

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