Solar Wind Magnetohydrodynamics Turbulence: Anomalous Scaling and Role of Intermittency

Salem, C. S.; Mangeney, A.; Bale, S. D.; Veltri, P.

doi:10.1088/0004-637x/702/1/537

Cited by 149 publications

(179 citation statements)

References 125 publications

Supporting

Mentioning

158

Contrasting

Order By: Relevance

“…Smallscale fluctuations of the SW velocity are observed to be highly intermittent too (e.g. [21,53]). The high intermittency of ion flux fluctuations on a scale of approximately 1 s was observed in our earlier works based on INTERBALL-1 measurements (see [54][55][56]).…”

Section: Introductionmentioning

confidence: 99%

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: 99%

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

“…For larger amplitudes and/or longer wavelengths τ NL k and τ L k become comparable, and the so-called strong turbulence in the critical balance regime is realized: τ L k τ NL k (Goldreich and Sridhar, 1995). Observations of intermittency in the inertial MHD range (Sorriso-Valvo et al, 1999;Salem et al, 2009) and in the range above the ion break (Alexandrova et al, 2008a) suggest the presence of a strongly turbulent fraction of fluctuations, but do not exclude the simultaneous presence of a weakly turbulent fraction, in particular in the MHD/kinetic transition range.…”

mentioning

confidence: 99%

Turbulent spectra and spectral kinks in the transition range from MHD to kinetic Alfvén turbulence

Voitenko

Keyser

2011

Nonlin. Processes Geophys.

View full text Add to dashboard Cite

Abstract.A weakly dispersive range (WDR) of kinetic Alfvén turbulence is identified and investigated for the first time in the context of the MHD/kinetic turbulence transition. We find perpendicular wavenumber spectra ∝ k −3 ⊥ and ∝ k −4 ⊥ formed in WDR by strong and weak turbulence of kinetic Alfvén waves (KAWs), respectively. These steep WDR spectra connect shallower spectra in the MHD and strongly dispersive KAW ranges, which results in a specific doublekink (2-k) pattern often seen in observed turbulent spectra. The first kink occurs where MHD turbulence transforms into weakly dispersive KAW turbulence; the second one is between weakly and strongly dispersive KAW ranges. Our analysis suggests that partial turbulence dissipation due to amplitude-dependent non-adiabatic ion heating may occur in the vicinity of the first spectral kink. The threshold-like nature of this process results in a conditional selective dissipation that affects only the largest over-threshold amplitudes and that decreases the intermittency in the range below the first spectral kink. Several recent counter-intuitive observational findings can be explained by the coupling between such a selective dissipation and the nonlinear interaction among weakly dispersive KAWs.

show abstract

“…This anisotropy has been attributed as indirect evidence for the presence of ion-cyclotron waves, as it has been suggested that resonant absorption of ion cyclotron waves heats and accelerates the ions in the solar wind (e.g., Axford & McKenzie 1992;Tu & Marsch 1997;Li et al 1999;Ofman et al 2001;Hollweg & Isenberg 2002;Jian et al 2014;Omidi et al 2014). Furthermore, observations by Helios, ACE, Wind, and Ulysses show that magnetic fluctuations in fast solar wind streams can be fitted by simple power laws in the inertia range and steeper spectrum in the dissipation range, providing clues on the possible heating mechanism (e.g., Bavassano et al 1982;Goldstein et al 1995;Podesta et al 2006;Vasquez et al 2007;Salem et al 2009). …”

Section: Introductionmentioning

confidence: 99%

Ion Heating in Inhomogeneous Expanding Solar Wind Plasma: The Role of Parallel and Oblique Ion-Cyclotron Waves

Ozak¹,

Ofman²,

Viñas³

2015

ApJ

View full text Add to dashboard Cite

Remote sensing observations of coronal holes show that heavy ions are hotter than protons and their temperature is anisotropic. In-situ observations of fast solar wind streams provide direct evidence for turbulent Alfvén wave spectrum, left-hand polarized ion-cyclotron waves, and He ++ -proton drift in the solar wind plasma, which can produce temperature anisotropies by resonant absorption and perpendicular heating of the ions. Furthermore, the solar wind is expected to be inhomogeneous on decreasing scales approaching the Sun. We study the heating of solar wind ions in inhomogeneous plasma with a 2.5D hybrid code. We include the expansion of the solar wind in an inhomogeneous plasma background, combined with the effects of a turbulent wave spectrum of Alfvénic fluctuations and initial ion-proton drifts. We study the influence of these effects on the perpendicular ion heating and cooling and on the spectrum of the magnetic fluctuations in the inhomogeneous background wind. We find that inhomogeneities in the plasma lead to enhanced heating compared to the homogenous solar wind, and the generation of significant power of oblique waves in the solar wind plasma. The cooling effect due to the expansion is not significant for super-Alfvénic drifts, and is diminished further when we include an inhomogeneous background density. We reproduce the ion temperature anisotropy seen in observations and previous models, which is present regardless of the perpendicular cooling due to solar wind expansion. We conclude that small scale inhomogeneities in the inner heliosphere can significantly affect resonant wave ion heating.

show abstract

Solar Wind Magnetohydrodynamics Turbulence: Anomalous Scaling and Role of Intermittency

Cited by 149 publications

References 125 publications

Dynamic properties of small-scale solar wind plasma fluctuations

Dynamic properties of small-scale solar wind plasma fluctuations

Turbulent spectra and spectral kinks in the transition range from MHD to kinetic Alfvén turbulence

Ion Heating in Inhomogeneous Expanding Solar Wind Plasma: The Role of Parallel and Oblique Ion-Cyclotron Waves

Contact Info

Product

Resources

About