Published online by Cambridge University Press: 12 April 2016
This review focusses on the most recent work which has been achieved concerning turbulence in stellar interiors. Among all possible causes for such turbulence, the most powerful is certainly the convective instability in unstably stratified regions, but little was known until now beyond the fact that thermal convection is capable of establishing an almost adiabatic stratification. The latest numerical simulations (Stein & Nordlund 1989; Cataneo et al. 1991) show that turbulent convection is highly intermittent, with strong downdrafts carrying most of the energy flux.
These plumes penetrate in the stable region below, which they render nearly adiabatic over some distance (Zahn 1991); the penetration depth should be measured soon through acoustic sounding of the Sun (Berthomieu et al. 1992). Such plumes are likely to exist also in a convective core, and to penetrate into the radiative region above (Roxburgh 1989).