A POSSIBLE MECHANISM FOR ENHANCED ABSORPTION OF P-MODES IN SUNSPOT AND PLAGE REGIONS

Magnetic regions on the Sun's surface are observed to absorb large fra ctions of the p-mode (acoustic) wave power incident upon them. We prop ose a mechanism to explain the absorption, based on the idea that suns pots are assembled from many individual flux tubes with highly variant physical conditions. Strong gradients in the (perturbed) parameters o f a wave propagating through such an inhomogeneous medium result in en hanced absorption of the wave power. The gradients in the wave paramet ers occur on the scale of the background flux tubes which is smaller t han the wavelength.