Hybrid simulation of foreshock waves and ion spectra and their linkage to cusp energetic ions

Wang, X. Y.; Lin, Y.; Chang, S.-W.

doi:10.1029/2008ja013745

Cited by 17 publications

(21 citation statements)

References 46 publications

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“…Note that in their work, the sinusoidal waves along the magnetic field lines are only weakly compressional because the analyzed trajectory starts farther away from the shock. Also, the decrease of the amplitude of the density and magnetic field strength fluctuations when moving away from the shock is consistent with the findings of Wang et al [] using 3‐D hybrid‐particle‐in‐cell simulations and of von Alfthan et al [] using hybrid Vlasov simulations. Spacecraft observations in the terrestrial foreshock have shown evidence of similar sinusoidal waves accompanied by density variations [e.g., Eastwood et al , ].…”

Section: Simulation 2: Magnetic Cloud With a Large Bx Componentsupporting

confidence: 90%

3D hybrid simulations of the interaction of a magnetic cloud with a bow shock

et al. 2015

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In this paper, we investigate the interaction of a magnetic cloud (MC) with a planetary bow shock using hybrid simulations. It is the first time to our knowledge that this interaction is studied using kinetic simulations which include self‐consistently both the ion foreshock and the shock wave dynamics. We show that when the shock is in a quasi‐perpendicular configuration, the MC's magnetic structure in the magnetosheath remains similar to that in the solar wind, whereas it is strongly altered downstream of a quasi‐parallel shock. The latter can result in a reversal of the magnetic field north‐south component in some parts of the magnetosheath. We also investigate how the MC affects in turn the outer parts of the planetary environment, i.e., from the foreshock to the magnetopause. We find the following: (i) The decrease of the Alfvén Mach number at the MC's arrival causes an attenuation of the foreshock region because of the weakening of the bow shock. (ii) The foreshock moves along the bow shock's surface, following the rotation of the MC's magnetic field. (iii) Owing to the low plasma beta, asymmetric flows arise inside the magnetosheath, due to the magnetic tension force which accelerates the particles in some parts of the magnetosheath and slows them down in others. (iv) The quasi‐parallel region forms a depression in the shock's surface. Other deformations of the magnetopause and the bow shock are also highlighted. All these effects can contribute to significantly modify the solar wind/magnetosphere coupling during MC events.

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Section: Simulation 2: Magnetic Cloud With a Large Bx Componentsupporting

confidence: 90%

3D hybrid simulations of the interaction of a magnetic cloud with a bow shock

et al. 2015

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“…Distribution B in the latter could be compared to the disrupted distributions (Figures 8 and 9 herein), distributions C and D are more difficult to associate. In Figure 2 of Wang et al [2009] the distributions are rather perturbed, so that they can be associated with the strongly disrupted distribution (Figure 9 herein). Distribution B also resembles a diffuse distribution (Figure 4 herein) since it shows particles streaming ahead of the core population.…”

Section: 1002/2014ja020519mentioning

confidence: 96%

Ion distributions in the Earth's foreshock: Hybrid‐Vlasov simulation and THEMIS observations

et al. 2015

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We present the ion distribution functions in the ion foreshock upstream of the terrestrial bow shock obtained with Vlasiator, a new hybrid-Vlasov simulation geared toward large-scale simulations of the Earth's magnetosphere (http://vlasiator.fmi.fi). They are compared with the distribution functions measured by the multispacecraft Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission. The known types of ion distributions in the foreshock are well reproduced by the hybrid-Vlasov model. We show that Vlasiator reproduces the decrease of the backstreaming beam speed with increasing distance from the foreshock edge, as well as the beam speed increase and density decrease with increasing radial distance from the bow shock, which have been reported before and are visible in the THEMIS data presented here. We also discuss the process by which wave-particle interactions cause intermediate foreshock distributions to lose their gyrotropy. This paper demonstrates the strength of the hybrid-Vlasov approach which lies in producing uniformly sampled ion distribution functions with good resolution in velocity space, at every spatial grid point of the simulation and at any instant. The limitations of the hybrid-Vlasov approach are also discussed.

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“…In some cases, results of numerical models can be used to quantify mean parameters of the magnetic field in the MSH like it was presented in Rakhmanova, Riazantseva, Zastenker, and Yermolaev (2017). If features of turbulent parameters in the MSH are known, a case study of rapid plasma measurements combined with the simulated magnetic field (e.g., Wang et al, 2009) would provide interesting results.…”

Section: Variability Of Spectral Shapes In the Mshmentioning

confidence: 99%

Kinetic‐Scale Ion Flux Fluctuations Behind the Quasi‐Parallel and Quasi‐Perpendicular Bow Shock

et al. 2018

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Properties of kinetic‐scale plasma turbulence are examined observationally with the help of Spektr‐R measurements in the Earth's magnetosheath. The statistics covers 6 years of ion flux measurements during years 2011–2017 and includes a few dozens of the magnetosheath crossings with total duration of 250 hr. Several types of Fourier spectra are distinguished in the magnetosheath according to a spectral shape at the scales of transition from magnetohydrodynamic to kinetic regimes. Spectral indices and occurrence rate of different spectral shapes are examined at different locations with respect to the magnetosheath boundaries—the magnetopause and the bow shock. Magnetosheath plasma behind the quasi‐parallel and quasi‐perpendicular bow shock is explored separately. Clear dynamics of spectral shapes across the magnetosheath is shown: spectra with broad bump at the transition frequencies occur more frequently in the vicinity of the bow shock, while spectra with plateau at the same frequencies are usually observed closer to the magnetopause. Spectral indices such as spectral slope at the kinetic scales and break frequency are shown to be weakly affected by the boundaries behind the quasi‐perpendicular bow shock. The steepest spectra are observed close to the quasi‐parallel bow shock.

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Hybrid simulation of foreshock waves and ion spectra and their linkage to cusp energetic ions

Cited by 17 publications

References 46 publications

3D hybrid simulations of the interaction of a magnetic cloud with a bow shock

3D hybrid simulations of the interaction of a magnetic cloud with a bow shock

Ion distributions in the Earth's foreshock: Hybrid‐Vlasov simulation and THEMIS observations

Kinetic‐Scale Ion Flux Fluctuations Behind the Quasi‐Parallel and Quasi‐Perpendicular Bow Shock

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