Ion Kinetic Scale in the Solar Wind Observed

Šafránková, Jana; Němeček, Zdenek; Přech, Lubomír; Zastenker, G. N.

doi:10.1103/physrevlett.110.025004

Cited by 74 publications

(69 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[24,41]), by the SW electron density measurements on ARTHEMIS spacecraft (e.g. [22]) and, at present, by the first results of fast BMSW measurements of some plasma parameters [23,27]. So, the BMSW measurements show, for the first time, the presence of a break point approximately 1 Hz in spectra of some direct plasma parameters fluctuations.…”

Section: Introductionmentioning

confidence: 78%

“…The first results provided by this instrument are published in [23,[34][35][36][37][38]. Such multiscale structure of SW is described in numerous papers (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…The systematic experimental investigation of the high-frequency range of plasma fluctuations became feasible only after the launch of the BMSW experiment. The first study of SW turbulence in [23] has shown that the frequency spectra of the density, velocity and thermal velocity exhibit the same behaviour at the magnetohydrodynamic (MHD) scale, but their spectra are remarkably different at the kinetic scale. The results of further studies of ion flux fluctuations are presented in this paper.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dynamic properties of small-scale solar wind plasma fluctuations

Рязанцева

Budaev

Zelenyǐ

et al. 2015

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

The paper presents the latest results of the studies of small-scale fluctuations in a turbulent flow of solar wind (SW) using measurements with extremely high temporal resolution (up to 0.03 s) of the bright monitor of SW (BMSW) plasma spectrometer operating on astrophysical SPECTR-R spacecraft at distances up to 350 000 km from the Earth. The spectra of SW ion flux fluctuations in the range of scales between 0.03 and 100 s are systematically analysed. The difference of slopes in low- and high-frequency parts of spectra and the frequency of the break point between these two characteristic slopes was analysed for different conditions in the SW. The statistical properties of the SW ion flux fluctuations were thoroughly analysed on scales less than 10 s. A high level of intermittency is demonstrated. The extended self-similarity of SW ion flux turbulent flow is constantly observed. The approximation of non-Gaussian probability distribution function of ion flux fluctuations by the Tsallis statistics shows the non-extensive character of SW fluctuations. Statistical characteristics of ion flux fluctuations are compared with the predictions of a log-Poisson model. The log-Poisson parametrization of the structure function scaling has shown that well-defined filament-like plasma structures are, as a rule, observed in the turbulent SW flows.

show abstract

Section: Introductionmentioning

confidence: 78%

“…The first results provided by this instrument are published in [23,[34][35][36][37][38]. Such multiscale structure of SW is described in numerous papers (e.g.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic properties of small-scale solar wind plasma fluctuations

Рязанцева

Budaev

Zelenyǐ

et al. 2015

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…The spacecraft was launched on 2011 July 18 into a highly elliptical orbit with an apogee of ≈50 R E and with an inclination of 65°. A detailed description of the BMSW instrument and the data processing havebeen reported previously (Šafránková et al 2008, 2013a, 2013bZastenker et al 2013);thus, only a brief introduction is given here. BMSW consists of six Faraday cups (FCs); three of them are directed toward the Sun, and they are equipped with deceleration grids for measurements of the ion distribution function.…”

Section: Data Setmentioning

confidence: 99%

Density Fluctuations Upstream and Downstream of Interplanetary Shocks

Pitňa

Šafránková

Němeček

et al. 2016

ApJ

View full text Add to dashboard Cite

Interplanetary (IP) shocks as typical large-scale disturbances arising fromprocesses such asstream-stream interactions or Interplanetary Coronal Mass Ejection (ICME) launching play a significant role in the energy redistribution, dissipation, particle heating, acceleration, etc. They can change the properties of the turbulent cascade on shorter scales. We focus on changes of the level and spectral properties of ion flux fluctuations upstream and downstream of fastforward oblique shocks. Although the fluctuation level increases by an order of magnitude across the shock, the spectral slope in the magnetohydrodynamic range is conserved. The frequency spectra upstream of IP shocks are the same as those in the solar wind (if not spoiled by foreshock waves). The spectral slopes downstream are roughly proportional to the corresponding slopes upstream, suggesting that the properties of the turbulent cascade are conserved across the shock;thus, the shock does not destroy the shape of the spectrum as turbulence passes through it. Frequency spectra downstream of IP shocks often exhibit "an exponential decay" in the ion kinetic range that was earlier reported at electron scales in the solar wind or at ion scales in the interstellar medium. We suggest that the exponential shape of ion flux spectra in this range is caused by stronger damping of the fluctuations in the downstream region.

show abstract

“…Here the turbulent spectra of plasma parameters (magnetic and electric fields, density, velocity and temperature) change their shape, and steeper spectra are observed at larger wave-numbers or higher frequencies, e.g. (Leamon et al 1998;Bale et al 2005;Alexandrova et al 2007;Šafránková et al 2013). There is a range of terminology used to describe this range, including "dissipation range", "dispersion range" and "scattering range".…”

Section: Turbulence At Kinetic Scalesmentioning

confidence: 99%

Solar Wind Turbulence and the Role of Ion Instabilities

et al. 2013

View full text Add to dashboard Cite

Solar wind is probably the best laboratory to study turbulence in astrophysical plasmas. In addition to the presence of magnetic field, the differences with neutral fluid isotropic turbulence are: (i) weakness of collisional dissipation and (ii) presence of several characteristic space and time scales. In this paper we discuss observational properties of solar wind turbulence in a large range from the MHD to the electron scales. At MHD scales, within the inertial range, turbulence cascade of magnetic fluctuations develops mostly in the plane perpendicular to the mean field, with the Kolmogorov scaling k −5/3 ⊥ for the perpendicular cascade and k −2 for the parallel one. Solar wind turbulence is compressible in nature: density fluctuations at MHD scales have the Kolmogorov spectrum. Velocity fluctuations do not follow magnetic field ones: their spectrum is a power-law with a −3/2 spectral index. Probability distribution functions of different plasma parameters are not Gaussian, indicating presence of intermittency. At the moment there is no global model taking into account all these observed properties of the inertial range. At ion scales, turbulent spectra have a break, compressibility increases and the density fluctuation spectrum has a local flattening. Around ion scales, magnetic spectra are variable and ion instabilities occur as a function of the local plasma parameters. Between ion and electron scales, a small scale turbulent cascade seems to be established. It is characterized by a well defined power-law spectrum in magnetic and density fluctuations with a spectral index close to −2.8. Approaching electron scales, the fluctuations are no more self-similar: an exponential cut-off is usually observed (for time intervals without quasi-parallel whistlers) indicating an onset of dissipation. The small scale inertial range between ion and electron scales and the electron dissipation range can be together described by ∼ k −α ⊥ exp(−k ⊥ d ), with α 8/3 and the dissipation scale d close to the electron Larmor radius d ρ e . The nature of this small scale cascade and a possible dissipation mechanism are still under debate.

show abstract

Ion Kinetic Scale in the Solar Wind Observed

Cited by 74 publications

References 33 publications

Dynamic properties of small-scale solar wind plasma fluctuations

Dynamic properties of small-scale solar wind plasma fluctuations

Density Fluctuations Upstream and Downstream of Interplanetary Shocks

Solar Wind Turbulence and the Role of Ion Instabilities

Contact Info

Product

Resources

About