Nonlinear evolution of torsional Alfvén waves

Abstract

Aims. We study the efficiency of the energy transfer to shorter scales in the field-aligned direction – the parallel nonlinear cascade – that accompanies the propagation of torsional Alfvén waves along open magnetic fields in the solar and stellar coronae, and compare it with the same effects for the shear Alfvén wave. The evolution of the torsional Alfvén wave is caused by the back reaction of nonlinearly induced compressive perturbations on the Alfvén wave.