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

B. Dintrans·A. Brandenburg·A. Nordlund·R. F. Stein
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Abstract

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 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.

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B. Dintrans, A. Brandenburg, A. Nordlund, R. F. Stein. 2005-04-11. Spectrum and amplitudes of internal gravity waves excited by penetrative convection in solar-type stars. https://doi.org/10.1051/0004-6361%3A20052831

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