INFRARED PROPERTIES OF AN ANISOTROPICALLY DRIVEN MHD TURBULENCE

The model of anisotropic magnetohydrodynamic turbulence is investigate d by the renormalization group approach. It is demonstrated that the i nclusion of small anisotropy into the model leads to increasing of the Lorentz force influence. This effect is especially important in the k inetic regime in which the Kolmogorov spectrum of pulsation energy tak es place. It is quite different from the isotropic case where the Lore ntz force has no influence on large scale properties of magnetohydrody namic turbulence, even if the external injection of energy is very int ensive. Therefore, the magnetic field behaves like a passive admixture . In the anisotropic MHD, nonlinear interactions generate modified ''a nisotropic Lorentz forces''. These forces are relevant for certain val ues of dimensionless parameter a, which describes the spectrum of the magnetic noise, and the magnetic field ceases to be a passive admixtur e. In particular, this statement is true for the most realistic value of a = 1 when the random magnetic force amplitude has the same dimensi onality as the energy injection rate.