NONLINEAR MHD SIMULATIONS OF WAVE DISSIPATION IN FLUX TUBES

The phase mixing and resonant dissipation of Alfven waves is studied i n both the 'closed' magnetic loops and the 'open' coronal holes observ ed in the hot solar corona. The resulting energy transfer from large t o small length scales contributes to the heating of these magnetic str uctures. The nonlinear simulations show that the periodically varying shear flows that occur in the resonant layers are unstable. In coronal holes, the phase mixing of running Alfven waves is speeded up by the 'flaring out' of the magnetic field lines in the lower chromosphere.