Magnetic turbulent spectra in the magnetosheath: new insights

Sahraoui, Fouad; Belmont, Gérard; Pinçon, Jean-Louis; Rezeau, Laurence; Balogh, A.; Robert, P.; Cornilleau‐Wehrlin, N.

doi:10.5194/angeo-22-2283-2004

Cited by 80 publications

(93 citation statements)

References 17 publications

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“…They find that a mirror mode propagating at an angle around 60 • to the background magnetic field dominates the wave field but there are also contributions from Alfvén, slow, and cyclotron wave modes. For the same data interval but for lower frequencies, Sahraoui et al (2004) find similar results, with the mirror modes propagating closer to the orthogonal direction at 80 • . Tjulin et al (2005) confirm the presence of mirror modes for the same interval by analyzing the electric field fluctuations after using both magnetic and electric field as input for the k-filtering.…”

Section: Magnetosheath Crossingsupporting

confidence: 72%

Low frequency wave sources in the outer magnetosphere, magnetosheath, and near Earth solar wind

Constantinescu

Glaßmeier²,

Décréau³

et al. 2007

Ann. Geophys.

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Abstract. The interaction of the solar wind with the Earth magnetosphere generates a broad variety of plasma waves through different mechanisms. The four Cluster spacecraft allow one to determine the regions where these waves are generated and their propagation directions. One of the tools which takes full advantage of the multi-point capabilities of the Cluster mission is the wave telescope technique which provides the wave vector using a plane wave representation. In order to determine the distance to the wave sources, the source locator -a generalization of the wave telescope to spherical waves -has been recently developed. We are applying the source locator to magnetic field data from a typical traversal of Cluster from the cusp region and the outer magnetosphere into the magnetosheath and the near Earth solar wind. We find a high concentration of low frequency wave sources in the electron foreshock and in the cusp region. To a lower extent, low frequency wave sources are also found in other magnetospheric regions.

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Section: Magnetosheath Crossingsupporting

confidence: 72%

Low frequency wave sources in the outer magnetosphere, magnetosheath, and near Earth solar wind

Constantinescu

Glaßmeier²,

Décréau³

et al. 2007

Ann. Geophys.

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“…The collective motion of particles arising due to the diamagnetic currents in such systems stimulates the development of low-frequency drift instabilities. Actually, results of the experimental observations of the spectra of low-frequency fluctuations in the magnetosphere (Sahraoui et al, 2003(Sahraoui et al, , 2004(Sahraoui et al, , 2006Mangeney et al, 2006;Alexandrova et al,, 2006;Narita et al, 2007), ionosphere (Lysak, 1990;Chaston et al, 1999;Stasiewicz et al, 2000;Abel et al, 2006) and experimental plasma devices (Browley and Mazzucato, 1985;Brower et al, 1987;Weissen et al, 1988;Gekelman, 1999), show that the observed fluctuations with the significant amplitude are produced due to the development of drift-Alfvén instability. One of the indications of the instability evolution in magnetized plasma is the shaping of the ordered wavy structures or vortexes, whose collective activity can finally lead to the formation of the turbulent state (Horton, 1990;Tu and Marsch, 1997;Aburjania,12 G. D. Aburjania et al: Model of strong stationary vortex turbulence Following its own logic of development, in the sixties of the last century, the plasma turbulence theory was based on the weak turbulence model when only the weak interaction between modes due to nonlinearity was taken into account.…”

Section: Introductionmentioning

confidence: 99%

Model of strong stationary vortex turbulence in space plasmas

Aburjania

Chargazia

Zelenyǐ

et al. 2009

Nonlin. Processes Geophys.

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Abstract. This paper investigates the macroscopic consequences of nonlinear solitary vortex structures in magnetized space plasmas by developing theoretical model of plasma turbulence. Strongly localized vortex patterns contain trapped particles and, propagating in a medium, excite substantial density fluctuations and thus, intensify the energy, heat and mass transport processes, i.e., such vortices can form strong vortex turbulence. Turbulence is represented as an ensemble of strongly localized (and therefore weakly interacting) vortices. Vortices with various amplitudes are randomly distributed in space (due to collisions). For their description, a statistical approach is applied. It is supposed that a stationary turbulent state is formed by balancing competing effects: spontaneous development of vortices due to nonlinear twisting of the perturbations' fronts, cascading of perturbations into short scales (direct spectral cascade) and collisional or collisionless damping of the perturbations in the short-wave domain. In the inertial range, direct spectral cascade occurs through merging structures via collisions. It is shown that in the magneto-active plasmas, strong turbulence is generally anisotropic Turbulent modes mainly develop in the direction perpendicular to the local magnetic field. It is found that it is the compressibility of the local medium which primarily determines the character of the turbulent spectra: the strong vortex turbulence forms a power spectrum in wave number space. For example, a new spectrum of turbulent fluctuations in k −8/3 is derived which agrees with available experimental data. Within the framework of the developed model particle diffusion processes are also investigated. It is found that the interaction of structures with each other and particles causes anomalous diffusion in the medium. The effective coefficient of diffusion has a square root dependence on the stationary level of noise.

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Section: Electron Scale Turbulencementioning

confidence: 99%

“…Indeed, only a handful of studies have been carried out in recent years (see e.g., Sahraoui et al 2003Sahraoui et al , 2004Mangeney et al 2006;Sahraoui et al 2006;Alexandrova et al 2008b;Yordanova et al 2008;He et al 2011). Two main similarities with solar wind turbulence emerged from those studies: the turbulence in strongly anisotropic (k k ⊥ ) at subproton and electron scales (Sahraoui et al 2004;Mangeney et al 2006;Sahraoui et al 2006) and kinetic instabilities and nonlinear structures are present (Sahraoui et al 2004;Sahraoui 2008;Alexandrova et al 2008b). Major differences with the solar wind do exist, however, e.g., (i) magnetosheath turbulence evolves in a 'confined' space limited by the bow shock and the magnetopause and these boundaries may influence the anisotropy of the turbulence (Sahraoui et al 2006;Yordanova et al 2008), and, (ii) in contrast to the solar wind, the fluctuations are dominated by zero-frequency compressible fluctuations (e.g., mirror modes Sahraoui et al 2006).…”

Section: Electron Scale Turbulencementioning

confidence: 99%

“…The method can be used on fully coupled electromagnetic wave time series provided the proper constraints (e.g., Faraday's Law) are in place (Tjulin et al 2005(Tjulin et al , 2008. P (ω, k), the main product of the k-filtering technique, has been used in a number of studies and in a number of different ways, including determining three-dimensional dispersion relations in identifying the plasma modes that characterize fluctuations in the magnetosheath (Glassmeier et al 2001;Sahraoui et al 2003Sahraoui et al , 2004, in the high latitude magnetic cusps (Grison et al 2005), in the magnetotail in conjunction with magnetic reconnection (Eastwood et al 2009;Huang et al 2010); and in the solar wind. Three-dimensional wavenumber spectra of turbulence have been produced by integrating over the angular frequencies P (k) = P (ω, k)dω in studies of lowfrequency magnetosheath turbulence (Sahraoui et al 2006), MHD-scale turbulence in the foreshock and solar wind (Narita et al 2006(Narita et al , 2010, and kinetic-scale turbulence in the solar wind (Sahraoui et al 2010b).…”

Section: Turbulencementioning

confidence: 99%

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Multipoint observations of plasma phenomena made in space by Cluster

et al. 2015

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Plasmas are ubiquitous in nature, surround our local geospace environment, and permeate the universe. Plasma phenomena in space give rise to energetic particles, the aurora, solar flares and coronal mass ejections, as well as many energetic phenomena in interstellar space. Although plasmas can be studied in laboratory settings, it is often difficult, if not impossible, to replicate the conditions (density, temperature, magnetic and electric fields, etc.) of space. Single-point space missions too numerous to list have described many properties of near-Earth and heliospheric plasmas as measured both in situ and remotely (see http://www.nasa.gov/missions/#.U1mcVmeweRY for a list of NASA-related missions). However, a full description of our plasma environment requires three-dimensional spatial measurements. Cluster is the first, and until data begin flowing from the Magnetospheric Multiscale Mission (MMS), the only mission designed to describe the three-dimensional spatial structure of plasma phenomena in geospace. In this paper, we concentrate on some of the many plasma phenomena that have been studied using data from Cluster. To date, there have been more than 2000 refereed papers published using Cluster data but in this paper we will, of necessity, refer to only a small fraction of the published work. We have focused on a few basic plasma phenomena, but, for example, have not dealt with most of the vast body of work describing dynamical phenomena in Earth's magnetosphere, including the dynamics of current sheets in Earth's magnetotail and the morphology of the dayside high latitude cusp. Several review articles and special publications are available that describe aspects of that research in detail and interested readers are referred to them (see for example, Escoubet et al.

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Magnetic turbulent spectra in the magnetosheath: new insights

Cited by 80 publications

References 17 publications

Low frequency wave sources in the outer magnetosphere, magnetosheath, and near Earth solar wind

Low frequency wave sources in the outer magnetosphere, magnetosheath, and near Earth solar wind

Model of strong stationary vortex turbulence in space plasmas

Multipoint observations of plasma phenomena made in space by Cluster

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