Astronomy and astrophysics vol:329 issue:2 pages:754-764
We study the heating of 2-D coronal arcades by linear resonant Alfven waves that are excited by photospheric footpoint motions of the magnetic field lines. The analysis is restricted to toroidally polarised footpoint motions so that Alfven waves are excited directly. At the magnetic surfaces where Alfven waves, travelling back and forth along the loop-like magnetic field lines, are in phase with the footpoint motions, the oscillations grow unbounded in ideal linear MHD. Inclusion of dissipation prevents singular growth and we can look at the steady state in which the energy input at the photospheric base of the arcade is balanced by the energy dissipated at the resonance layer.