Statistical anisotropy of magnetohydrodynamic turbulence

Direct numerical simulations of decaying and forced magnetohydrodynamic (MHD) turbulence without and with mean magnetic field are analyzed by higher-order two-point statistics. The turbulence exhibits statistical anisotropy with respect to the direction of the local magnetic field even in the case of global isotropy. A mean magnetic field reduces the parallel-field dynamics while in the perpendicular direction a gradual transition towards two-dimensional MHD turbulence is observed with k-3/2 inertial-range scaling of the perpendicular energy spectrum. An intermittency model based on the log-Poisson approach, ζp=p/g2+1-(1/g)p/g, is able to describe the observed structure function scalings