Granulation, Magneto-Hydrodynamic Waves, and the Heating of the Solar Corona

In an electrically conducting liquid situated in a magnetic field any motion gives rise to magneto-hydrodynamic waves. Since the granulation is considered to constitute a turbulence in the photosphere, it must produce magneto-hydrodynamic waves, which are transmitted upwards to the chromosphere and the corona. The energy of the waves is estimated to the order of one per cent of the energy radiated by the Sun. It is shown that the waves are damped mainly in the inner corona where their energy is converted into heat. It is possible that the very high temperature found in the corona is produced through this magneto-hydrodynamic heating.