High-frequency plasma fluctuations in the middle magnetosheath and near its boundaries: Spektr-R observations

Rakhmanova, L. S.; Рязанцева, М. О.; Zastenker, G. N.; Yermolaev, Yu. I.

doi:10.1017/s002237781700023x

Cited by 10 publications

(20 citation statements)

References 71 publications

(187 reference statements)

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“…Slopes of the kinetic part of the spectra are shown to become slightly flatter across the quasi‐perpendicular part of the MSH: S 2 changes from −3.2 in the BS vicinity to −2.8 in the MP vicinity. Previously, steepening of the spectra toward the MP was shown in the case study by Rakhmanova, Riazantseva, Zastenker, and Yermolaev (). This difference underlines the importance of statistical exploration of turbulence in the MSH.…”

Section: Discussionmentioning

confidence: 76%

“…The break frequency changes slightly across the quasi-perpendicular part of the MSH from 0.7 Hz near the BS to 0.8 Hz near the MP. Increase of the break frequency toward the MP was shown in Rakhmanova, Riazantseva, Zastenker, and Yermolaev (2017) also. The break frequency changes from 0.6 to 0.7 Hz in the MSH behind the quasi-parallel BS.…”

Section: Journal Of Geophysical Research: Space Physicsmentioning

confidence: 71%

“…Spectra of this type are believed to be common in the SW and MSH. However, Riazantseva et al () and Rakhmanova, Riazantseva, Zastenker, and Yermolaev () showed variability of shapes of the ion flux fluctuation spectra. In the current study the spectra of different shapes are analyzed separately.…”

Section: Methodsmentioning

confidence: 99%

“…Kinetic‐scale plasma fluctuations have been explored systematically since 2011 with the help of the BMSW (Fast Solar Wind Monitor, Šafránková, Němeček, Přech, Zastenker, Cěrmák, et al, ; Zastenker et al, ) instrument on board Spektr‐R spacecraft. Parameters of plasma turbulence based on BMSW measurements were considered in the SW (Chen et al, ; Riazantseva et al, , , ; Šafránková, Němeček, Přech, & Zastenker, ; Šafránková et al, , ) as well as in the flank MSH (Rakhmanova et al, ; Rakhmanova, Riazantseva, Zastenker & Yermolaev, ; Riazantseva et al, , ). The BMSW data set covers 6 years of continuous plasma measurements in the SW and MSH that allow for statistical study of plasma fluctuations for various ambient conditions and upstream SW parameters.…”

Section: Introductionmentioning

confidence: 99%

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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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Section: Discussionmentioning

confidence: 76%

Section: Journal Of Geophysical Research: Space Physicsmentioning

confidence: 71%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

et al. 2018

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“…However, the spatial evolution of magnetosheath turbulence has not been comprehensively addressed except for a few studies. Based on a previous case study, the intermittency of plasma turbulence increases in amplitude and anisotropy away from the bow shock (Yordanova et al 2008), and the break frequency of ionflux spectra evolves to higher frequencies approaching the magnetopause (Rakhmanova et al 2017). From a statistical perspective, Guicking et al (2012) find a decay of wave intensity of low-frequency magnetic-field fluctuations along the streamlines in the Earth's magnetosheath, which quantitatively agrees with the theoretical concept of freely evolving/decaying turbulence; Huang et al (2017) find that the ∼f −1 spectral scaling of magnetic-field spectra at MHD scales is more likely located in the vicinity of the bow shock, while the Kolmogorov-like scaling at MHD scales located away from the bow shock toward the flank and magnetopause regions.…”

Section: Introductionmentioning

confidence: 99%

Evolution of the Earth’s Magnetosheath Turbulence: A Statistical Study Based on MMS Observations

Jiang

Wang

et al. 2020

ApJL

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Composed of shocked solar wind, the Earth's magnetosheath serves as a natural laboratory to study the transition of turbulence from low Alfvén Mach number, M A , to high M A. The simultaneous observations of magnetic field and plasma moments with unprecedented high temporal resolution provided by NASA's Magnetospheric Multiscale Mission (MMS) enable us to study the magnetosheath turbulence at both magnetohydrodynamics (MHD) and sub-ion scales. Based on 1841 burst-mode segments of MMS-1 from 2015 September to 2019 June, comprehensive patterns of the spatial evolution of magnetosheath turbulence are obtained: (1) from the subsolar region to the flanks, M A increases from <1 to >5. At MHD scales, the spectral indices of the magnetic-field and velocity spectra present a positive and negative correlation with M A. However, no obvious correlations between the spectral indices and M A are found at sub-ion scales. (2) From the bow shock to the magnetopause, the turbulent sonic Mach number, M turb , generally decreases from >0.4 to <0.1. All spectra steepen at MHD scales and flatten at sub-ion scales, representing positive/negative correlations with M turb. The break frequency increases by 0.1 Hz when approaching the magnetopause for the magnetic-field and velocity spectra, while it remains at 0.3 Hz for the density spectra. (3) In spite of minor differences, similar results are found for the quasi-parallel and quasi-perpendicular magnetosheath. In addition, such spatial evolution of magnetosheath turbulence is found to be independent of the upstream solar wind conditions, e.g., the averaged Z-component of the interplanetary magnetic field and solar wind speed.

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Variety of shapes of solar wind ion flux spectra: Spektr-R measurements

et al. 2017

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The paper is devoted to the shapes of the solar wind ion flux fluctuation spectrum at the transition between the inertial and the kinetic range using in situ high-resolution measurements of the Russian mission Spektr-R. We analyse the variability of the transition region and select five typical types of spectral shapes: (i) spectra with two slopes and one break, (ii) spectra characterized by a nonlinear steepening in the kinetic range, (iii) spectra with flattening in the vicinity of the break, (iv) spectra with a bump in the vicinity of the break and (v) spectra without any steepening in the kinetic range. The most popular is the well-known type (i) observed in approximately half of the cases. The second most popular type of spectra is type (iii) occurring in approximately one third of the cases. The other three types are observed less often: type (ii) – in approximately 6 %; type (iv) in 3 % and type (v) in 6 % of cases. An analysis of typical plasma conditions for different types of spectra revealed that the last two type of spectra (iv) and (v) are generally observed in a very slow solar wind with a low proton density, (i) and (iii) are observed in the solar wind with rather typical conditions and (ii) is usually observed in high-speed streams. The effect of nonlinear steepening of the spectra in the kinetic range increases with the solar wind speed. We present also the analysis of statistical properties of the observed events and compare them with the predictions of several statistical turbulence models. We show that intermittency is always observed in the solar wind flow despite the presence of one or another shape of spectra. The log-Poisson model with a dominant contribution of filament-like structures shows the best parameterization of the experimentally observed scaling.

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High-frequency plasma fluctuations in the middle magnetosheath and near its boundaries: Spektr-R observations

Cited by 10 publications

References 71 publications

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

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

Evolution of the Earth’s Magnetosheath Turbulence: A Statistical Study Based on MMS Observations

Variety of shapes of solar wind ion flux spectra: Spektr-R measurements

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