TAPIR Seminar

Convection adjacent to a radiative zone can excite internal waves. This occurs in a wide range of astrophysical settings including most stars, some gas giants like Saturn, and the cores of some rocky planets like the Earth. We will present a theoretical calculation of the wave excitation spectrum, and discuss some astrophysical implications. To test this theory, we present an experimental study of wave excitation by convection in water. We then perform 2D simulations of the experiment using the open-source Dedalus code (dedalus-project.org). Our simulations show that waves are excited from within the convection zone, opposed to at the interface between the convective and stably stratified regions, consistent with our theoretical model. We will also present 3D simulations of internal wave excitation by convection in a fully compressible atmosphere with multiple density scaleheights. These simulations provide greater freedom in choosing the thermal equilibrium of the system, and are run at higher Rayleigh number. The simulated waves are then compared to the theoretical predictions of our model.