Dynamics and statistics of inverse cascade processes in 2D magnetohydrodynamic turbulence

The inverse cascade of the mean square potential A in a 2D magnetofluid randomly forced at small scales is studied by numerical simulation. One finds the spectrum Ak ≅ 2.6 element of A2/3k-7/3. The cascade proceeds by coalescence of current filaments, which is a fast reconnection process owing to high turbulent resistivity. Statistics of δvl and δBl are strictly Gaussian, also in the condensation phase of Ak at k 1. Only when the coherent magnetic field intensity exceeds that of the fluctuations, non-Gaussian statistics in δB6 occur, which are, however, entirely due to the static magnetic structure and not associated with intermittency of the small-scale turbulence, the latter remaining Gaussian. (orig.)