Solar Wind Turbulence and the Role of Ion Instabilities
By O. Alexandrova, C. Chen, L. Sorriso-Valvo, T. Horbury, S. Bale. 2013
266 citations recorded by the source corpus.
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 $k_{\perp}^{-5/3}$ 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 $\sim k_{\perp}^{-\alpha}\exp(-k_{\perp}\ell_{d})$, with α≃8/3 and the dissipation scale ℓd close to the electron Larmor radius ℓd≃ρe. The nature of this small scale cascade and a possible dissipation mechanism are still under debate.
Subfields: Astronomy and Astrophysics, Molecular Biology
View Paper: https://www.semanticscholar.org/paper/7f6460364b59fd158fff31dbfc258610c209e166
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Astronomy and Astrophysics
In Molecular Biology
Citations in the corpus
- Nature of Kinetic Scale Turbulence in the Earth's Magnetosheath (2016, background): “The majority of observations of turbulence at kinetic scales are from the solar wind upstream of the Earth’s bow shock (e.g., Bruno & Carbone 2013; Alexandrova et al. 2013; Goldstein et al. 2015; Chen 2016).”
- The Evolution and Role of Solar Wind Turbulence in the Inner Heliosphere (2019, background): “…measure the turbulence energy flux within the solar corona to determine its contribution to solar wind acceleration, examine the turbulence (Alexandrova et al. 2013; Chen 2016; Chen & Boldyrev 2017; Duan 2019) and fieldparticle interactions (Chen et al. 2019) at kinetic scales to…”
- First In Situ Measurements of Electron Density and Temperature from Quasi-thermal Noise Spectroscopy with Parker Solar Probe/FIELDS (2019, background): “A question of considerable importance is the relationship between the small-scale structure associated with density fluctuations and large-scale plasma properties (Alexandrova et al. 2013; Lacombe et al. 2014; Lion et al. 2016).”
- Recent progress in astrophysical plasma turbulence from solar wind observations (2016, background): “It is not intended to be a complete review; for general review papers on solar wind observations see, e.g., Alexandrova et al. (2013), Bruno & Carbone (2013), and the collection of Kiyani et al. (2015).”