Characterizing the dynamic properties of the solar turbulence with 3 - D simulations : Consequences in terms of p - mode excitation

Characterizing the dynamic properties of the solar turbulence with 3-D simulations: Consequences in terms of p-mode excitation. Abstract. A 3D simulation of the upper part of the solar convective zone is used to derive constraints about the averaged and dynamic properties of solar turbulent convection. Theses constraints are then used to compute the acoustic energy supply rate P injected into the solar radial oscillations according to the theoretical expression in Samadi & Goupil (2001). The result is compared with solar seismic data. Assuming, as it is usually done, a gaussian model for the frequency component χ k (ν) of the model of turbulence, it is found that the computed P (ν) is underestimated compared with the solar seismic data by a factor ∼ 2.5. A frequency analysis of the solar simulation shows that the gaussian model indeed does not correctly model χ k (ν) in the frequency range where the acoustic energy injected into the solar p-modes is important (ν ≃ 2 − 4 mHz). One must consider an additional non-gaussian component for χ k (ν) to reproduce its behavior. Computed values of P obtained with this non-gaussian component reproduce better the solar seismic observations. This non-gaussian component leads to a Reynolds stress contribution of the same order than the one arising from the advection of the turbulent fluctuations of entropy by the turbulent motions.