Dynamic anisotropy in MHD turbulence induced by mean magnetic field

Abstract

In this paper, we study the development of anisotropy in strong MHD turbulence in the presence of a large scale magnetic field B0 by analyzing the results of direct numerical simulations. Our results show that the developed anisotropy among the different components of the velocity and magnetic field is a direct outcome of the inverse cascade of energy of the perpendicular velocity components u⊥ and a forward cascade of the energy of the parallel component u∥. The inverse cascade develops for a strong B0, where the flow exhibits a strong vortical structure by the suppression of fluctuations along the magnetic field. Both the inverse and the forward cascade are examined in detail by investigating the anisotropic energy spectra, the energy fluxes, and the shell to shell energy transfers among different scales.