Convection and its influence on oscillations

Abstract

We investigate the interaction between p-mode oscillations and convection using a realistic, three-dimensional simulation of the upper solar convection zone. P-mode oscillations are excited at the eigenfrequencies of the simulation volume. Their frequency is different than that found from one-dimensional mixing length models. Their resonant cavity becomes larger when overshooting into the photosphere is possible, which lowers the mode frequencies, while interaction with the inhomogeneities in the sound speed and the motions generated by the convection tends to raise the mode frequencies. The modes are excited stochastically by non-adiabatic fluctuations in the gas pressure caused by the switch from convective to radiative energy transport at the solar surface.