Spectral anisotropies and intermittency of plasma turbulence at ion kinetic scales
Abstract
By means of three dimensional highresolution hybrid simulations we study the properties of the magnetic field spectral anisotropies near and beyond ion kinetic scales. By using both a Fourier analysis and a local analysis based on multipoint 2ndorder structure function techniques, we show that the anisotropy observed is less than what expected by standard wave normal modes turbulence theories although the non linear energy transfer is still in the perpendicular direction, only advected in the parallel direction as expected balancing the nonlinear energy transfer time and the decorrelation time. Such result can be explained by a phenomenological model based on the formation of strong intermittent twodimensional structures in the plane perpendicular to the local mean field that have some prescribed aspect ratio eventually depending on the scale. This model support the idea that small scales structures, such as reconnecting current sheets, contribute significantly to the formation of the turbulent cascade at kinetic scales.
 Publication:

arXiv eprints
 Pub Date:
 April 2019
 DOI:
 10.48550/arXiv.1904.03903
 arXiv:
 arXiv:1904.03903
 Bibcode:
 2019arXiv190403903L
 Keywords:

 Astrophysics  Solar and Stellar Astrophysics;
 Physics  Plasma Physics;
 Physics  Space Physics
 EPrint:
 9 pages, 4 figures