Effect of the radiative damping on magnetohydrodynamic waves in an isothermal medium (Q1607857)

A linearized theory of magnetoatmospheric waves involving the combined effect of restoring forces due to compressibility, magnetic pressure, and radiative damping is developed for the case of a uniform horizontal magnetic field. It is shown that the magnetic field produces a totally reflecting layer. Consequently, the atmosphere can be divided into two distinct regions. In the lower region, the solution is a linear combination of an upward and a downward propagating wave, and in the upper region the solution decays exponentially or behaves like a constant. These two regions are connected by a region in which the reflection and transmission of the waves takes place. The heat radiation affects only the lower region and changes the sound speed from the adiabatic value to the isothermal one. The reflection coefficient and the attenuation factor of the wave amplitude are derived for all values of heat radiation coefficient. The conclusions are presented in connection with the heating process of the solar atmosphere.