Ion jetting at the plasma sheet boundary: Simultaneous observations of incident and reflected particles

Andrews, M. K.; Daly, P. W.; Keppler, E.

doi:10.1029/gl008i009p00987

Cited by 55 publications

(24 citation statements)

References 7 publications

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“…[1979] demonstrated that the vertical motion of the plasma sheet has velocities ranging from 10 to 60 kmls. This was later confirmed by Andrews et al [1981], Forbes et al [1981a, b], and Eastman et at. [1985].…”

Section: -0227195195ja-00902$0500supporting

confidence: 74%

“…A number of studies [Mobius. et al, 1980;Andrews et al, 1981;Williams, 1981;Eastman et at., 1984Eastman et at., , 1985Takahashi and Hones, 1988] have established that the PSBL is nearly always present, and velocities as high as 1000 kmls are detected even during quiet times [Takahashi and Hones, 1988]. Takahashi and Hones [1988] estimated that the outermost 19,192 ASHOUR-ABDALLA ET AL.…”

Section: -0227195195ja-00902$0500mentioning

confidence: 99%

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The mosaic structure of plasma bulk flows in the Earth's magnetotail

Ashour‐Abdalla¹,

Zelenyǐ²,

Peroomian³

et al. 1995

J. Geophys. Res.

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Moments of plasma distributions observed in the magnetotail vary with different time scales. In this paper we attempt to explain the observed variability on intermediate timescales of ∼10–20 min that result from the simultaneous energization and spatial structuring of solar wind plasma in the distant magnetotail. These processes stimulate the formation of a system of spatially disjointed, highly accelerated filaments (beamlets) in the tail. We use the results from large‐scale kinetic modeling of magnetotail formation from a plasma mantle source to calculate moments of ion distribution functions throughout the tail. Statistical restrictions related to the limited number of particles in our system naturally reduce the spatial resolution of our results, but we show that our model is valid on intermediate spatial scales Δx × ΔZ ∼ 1 RE × 1000 km. For these spatial scales the resulting pattern, which resembles a mosaic, appears to be quite variable. The complexity of the pattern is related to the spatial interference between beamlets accelerated at various locations within the distant tail which mirror in the strong near‐Earth magnetic field. Global motion of the magnetotail results in the displacement of spacecraft with respect to this mosaic pattern and can produce variations in all of the moments (especially the x‐component of the bulk velocity) on intermediate timescales. The results obtained enable us to view the magnetotail plasma as consisting of two different populations: a tail ward‐Earthward system of highly accelerated beamlets interfering with each other, and an energized quasithermal population which gradually builds as the Earth is approached. In the near‐Earth tail, these populations merge into a hot quasi‐isotropic ion population typical of the near‐Earth plasma sheet. The transformation of plasma sheet boundary layer (PSBL) beam energy into central plasma sheet (CPS) quasi‐thermal energy occurs in the absence of collisions or noise. This paper also clarifies the relationship between the global scale where an MHD description might be appropriate and the lower intermediate scales where MHD fails and large‐scale kinetic theory should be used.

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Section: -0227195195ja-00902$0500supporting

confidence: 74%

Section: -0227195195ja-00902$0500mentioning

confidence: 99%

The mosaic structure of plasma bulk flows in the Earth's magnetotail

Ashour‐Abdalla¹,

Zelenyǐ²,

Peroomian³

et al. 1995

J. Geophys. Res.

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“…Sauvaud et al 1999;Sergeev et al 2000b). Ion energy dispersion in such structures is basically formed as a result of three main effects: (1) the pure time-of-flight (TOF) effect, which spreads ions of different energies along the magnetic field line; (2) the VF effect due to magnetotail E × B convection, which produces an equatorward drift of accelerated ions while they propagate from their source to the Earth (Andrews et al 1981;Williams 1981); and (3) the "place of birth" (PB) effect related to the ion acceleration mechanism whose efficiency might depend on the local conditions in the CS, such that the energy gained by the ions during their interaction with the CS may vary with location (Ashour-Abdalla et al 1993). The VF effect produces a spatial structuring (layering) of ions according to their energy value, with the highest-energy ions appearing closest to the lobeward edge of PSBL and lower energy ions showing deeper in the PSBL (e.g.…”

Section: Possible Auroral Manifestations Of Psbl Ion Beamsmentioning

confidence: 99%

Non-adiabatic Ion Acceleration in the Earth Magnetotail and Its Various Manifestations in the Plasma Sheet Boundary Layer

et al. 2011

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Many physical phenomena in space involve energy dissipation which generally leads to charged particle acceleration, often up to very high energies. In the Earth magnetosphere energy accumulation and release occur in the magnetotail, namely in its Current Sheet (CS). The kinetic analysis of non-adiabatic ion trajectories in the CS region with finite but positive normal component of the magnetic field demonstrated that this region is essentially non-uniform in terms of scattering characteristics of ion orbits and contains spatially localized, well-separated sites of enhanced and reduced chaotization. The latter represent sources from which accelerated and energy-collimated ions are ejected into Plasma Sheet 134 E.E. Grigorenko et al.Boundary Layer (PSBL) and stream towards the Earth. Numerical simulations performed as part of a Large-Scale Kinetic Model have shown the multiplet ion structure of the PSBL is formed by a set of ion beams (beamlets) localized both in physical and velocity space. This structure of the PSBL is quite different from the one produced by CS acceleration near a magnetic reconnection region in which more energetic ion beams are generated with a broad range of parallel velocities. Multi-point Cluster observations in the magnetotail PSBL not only showed that non-adiabatic ion acceleration occurs on closed magnetic field lines with at least two CS sources operating simultaneously, but also allowed an estimation of their spatial and temporal characteristics. In this paper we discuss and compare the PSBL manifestations of both mechanisms of CS particle acceleration: one based on the peculiar properties of non-adiabatic ion trajectories which operates on closed magnetic field lines and the other representing the well-explored mechanism of particle acceleration during the course of magnetic reconnection. We show that these two mechanisms supplement each other and the first operates mostly during quiescent magnetotail periods.

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“…From the detailed observation, of a multiple encounter with this layer of flowing plasma they infer either a multiple a tructure or a wave-like modulation of the plasma sheet boundary surface. Andrews et al (1981) have observed, on ISEE-2 at ti15 RE , a structured layer of ions between 25 keV and 2.5 MeV jetting towards the Earth at the plasma sheet boundary, together with the tailward return flow of mirroring ions. The energy dispersion characteristics of these ions are explained as the effects of their flow in the magnetotail E field and of the motion of their source.…”

Section: Introductionmentioning

confidence: 99%

The structure of the plasma sheet‐lobe boundary in the Earth's magnetotail

Orsini¹,

Candidi²,

Formisano³

et al. 1984

J. Geophys. Res.

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The structure of the magnetotail plasma sheet‐plasma lobe boundary is studied by observing the properties of tailward flowing O+ ion streams. These have been detected by the ISEE 2 plasma experiment and the ISEE 1 ion composition experiment inside the boundary during three time periods in April 1978; data from the ISEE 1 electron spectrometer are used to define the location of the boundary. The density of the O+ ion streams has a relative maximum, and their velocity has a relative minimum at the boundary. The xy drift velocity component across the local magnetic field reverses at the boundary, indicating a reversal of the Ez electric field component. These changes are consistent with the topology of the electric field lines in the tail as mapped from the ionosphere.

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Ion jetting at the plasma sheet boundary: Simultaneous observations of incident and reflected particles

Cited by 55 publications

References 7 publications

The mosaic structure of plasma bulk flows in the Earth's magnetotail

The mosaic structure of plasma bulk flows in the Earth's magnetotail

Non-adiabatic Ion Acceleration in the Earth Magnetotail and Its Various Manifestations in the Plasma Sheet Boundary Layer

The structure of the plasma sheet‐lobe boundary in the Earth's magnetotail

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