Propagation of magnetohydrodynamic waves in the solar atmosphere - Alfven p-waves in sunspots

Abstract

Numerical calculations are given for the propagation of Alfven p-waves in the solar atmosphere for Geronicolas' (1977) sunspot model. It is shown that Alfven p-waves with a period greater than 400s do not, in fact, penetrate into upper layers of a sunspot. This is due to the reflection of Alfven p-waves from the upper layers and to coupling with magnetogravity waves trapped at a particular layer of a sunspot. Proper resonance periods for magnetogravity waves in a sunspot are calculated