On the efficiency of coronal loop heating by resonant absorption

The heating of solar coronal loops by resonant absorption of Alfven waves is investigated in the framework of linearized compressible resistive MHD. The resonant absorption of the waves incident on the coronal loops is numerically simulated in straight cylindrical, axisymmetric loop models externally excited by a periodic source. The stationary state of this driven system and the ohmic dissipation rate in this state are determined by a very accurate code based on the finite element technique. The efficiency of the heating mechanism and the energy deposition profile in this stationary state strongly depend on the characteristics of both the external driver and the equilibrium. It is shown that resonant absorption is very efficient for typical coronal loops as a considerable part of the energy supplied by the external source is actually dissipated ohmically and converted into heat. The heating rate is proportional to the square of the magnitude of the background magnetic field.