p-mode interaction with sunspots

Abstract

This chapter brings together two of the prominent features of our star the Sun: its well‐developed p‐mode spectrum of global oscillations excited by near‐surface convection, and its magnetic activity famously represented by sunspots. Modern developments in observations of p‐mode and sunspot magnetic field interactions have helped bridge the gap between theory and observations: both the oscillations within a sunspot and in the immediate surroundings of the sunspot appear to be due to magnetohydrodynamics waves driven by p‐modes with characteristic spatial patterns of frequencies intimately related to magnetic inclination and the height variation of the plasma p = 1 layer. The chapter makes the case that the behavior of waves in sunspots is dominated by four processes: the ramp effect; fast‐to‐slow mode conversion; fast‐wave reflection; and fast‐to‐Alfvén mode conversion. The chapter then discusses some of the major developments in helioseismic forward and inverse modeling that have occurred over the last decade.