In solar-like stars the acoustic oscillations are intrinsically damped but excited stochastically by the turbulent motion of the gas in the outer stellar layers.Nonadiabatic model computations are necessary to estimate the characteristic timescale over which the amplitudes of these oscillations decay. This demands a time-dependent treatment of the turbulent fluxes of heat and momentum. The Figure shows a contour plot of the oscillation amplitude in solar-type stars (brighter colours indicate larger amplitudes).

The design and analysis of low-degree seismic signatures of the structure of spherical stars is of central importance to asteroseismic diagnosis. Spatially localized inhomogeneities in any oscillating system impose an oscillatory component on the frequency spacing of the oscillations. By analysing the resulting oscillatory component the helium abundance, for example, can be measured. The Figure shows the oscillatory component in the frequency spacing for solar data.

In stars with convectively unstable layers the stellar oscillations are coupled to the turbulent velocity field. Consequently a time-dependent convection model is needed for modelling the observed oscillation properties. Such a time-dependent convection model has been tested successfully for radial pulsations. It needs to be generalized to accommodate time-varying large-scale shear, so that it may then be applied to gravity-mode pulsation in stars such as γ Doradus stars. The Figure shows the Nusselt number as a function of Rayleigh number in Rayleigh-Bénard convection and for various values of the gradient Richardson number.