PROPAGATION OF MHD BODY AND SURFACE-WAVES IN MAGNETICALLY STRUCTURED REGIONS OF THE SOLAR ATMOSPHERE

The fact that magnetically structured regions exist in the solar atmos phere has been known for a number of years. It has been suggested that different kinds of magnetohydrodynamic (MHD) waves can be efficiently damped in these regions and that the dissipated wave energy may be re sponsible for the observed enhancement in radiative losses. From a the oretical point of view, an important task would be to investigate the propagation and dissipation of MHD waves in these highly structured re gions of the solar atmosphere. In this paper, we study the behavior of MHD body and surface waves in a medium with either a single or double (slab) magnetic interface by use of a nonlinear, two-dimensional, tim e-dependent, ideal MHD numerical model constructed on the basis of a L agrangean grid and semi-implicit scheme. The processes of wave confine ment and wave energy leakage are discussed in detail. It is shown that the obtained results depend strongly on the type of perturbations imp osed on the interface or slab and on the plasma parameter, beta. The r elevance of the obtained results to the heating problem of the upper p arts of the solar atmosphere is also discussed.