ACOUSTIC-WAVE GENERATION IN VERTICAL MAGNETIC-FIELDS

We extended Stein's hydrodynamic theory of acoustic wave generation to accommodate the effect of a vertically uniform magnetic field. It is shown that in the presence of a uniform vertical field with pure horizontal field fluctuations the acoustic waves are produced both from a non-magnetic monopole source of the Reynolds stress and by the magnetic field fluctuations. The computed acoustic flux is found to be confined to the topmost of the spot's convection zone with a small range of depth.