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arXiv · 1606.00466

A statistical model of three-dimensional anisotropy and intermittency in strong Alfvénic turbulence

A. Mallet·A. A. Schekochihin
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Abstract

We propose a simple statistical model of three-dimensionally anisotropic, intermittent, strong Alfvénic turbulence, incorporating both critical balance and dynamic alignment. Our model is based on log-Poisson statistics for Elsasser-field increments along the magnetic field. We predict the scalings of Elsasser-field conditional two-point structure functions with point separations in all three directions in a coordinate system locally aligned with the direction of the magnetic field and of the fluctuating fields and obtain good agreement with numerical simulations. We also derive a scaling of the parallel coherence scale of the fluctuations, $l_\parallel \propto λ^{1/2}$, where $λ$ is the perpendicular scale. This is indeed observed for the bulk of the fluctuations in numerical simulations.

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A. Mallet, A. A. Schekochihin. 2016-12-14. A statistical model of three-dimensional anisotropy and intermittency in strong Alfvénic turbulence. https://doi.org/10.1093/mnras%2Fstw3251

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