Spectrum and amplitudes of internal gravity waves excited by penetrative convection in solar-type stars

B. Dintrans, A. Brandenburg, Å. Nordlund, R. F. Stein
2005 Astronomy and Astrophysics  
The excitation of internal gravity waves by penetrative convective plumes is investigated using 2-D direct simulations of compressible convection. The wave generation is quantitatively studied from the linear response of the radiative zone to the plumes penetration, using projections onto the g-modes solutions of the associated linear eigenvalue problem for the perturbations. This allows an accurate determination of both the spectrum and amplitudes of the stochastically excited modes. Using
more » ... ed modes. Using time-frequency diagrams of the mode amplitudes, we then show that the lifetime of a mode is around twice its period and that during times of significant excitation up to 40% of the total kinetic energy may be contained into g-modes.
doi:10.1051/0004-6361:20052831 fatcat:agxmsop2ujfo7fe3dop7belp6e