Penetrative Turbulent Compressible Convection

The outer third of the Sun's radius is convectively unstable. Turbulent motions from this region known as Penetrative Turbulent Compressible Convection (PTCC) may penetrate into stable layers below, mixing temperature, momentum and chemicals.The outer third of the Sun's radius is convectively unstable. Very turbulent motions from this zone may penetrate into stable layers below, mixing temperature, momentum and chemicals significantly there. In an attempt to understand such processes, researchers at Colorado University created a simple model of this situation. Shown here is a visualization of enstrophy (vorticity squared) from such a simulation of penetrative turbulent convection in a compressible ideal gas (PTCC). The physical domain is divided into two halves, where the upper is unstably stratified and the lower is stably stratified, enforced by an imposed thermal conductivity profile. Intense enstrophy structures (bright yellow, opaque) can be seen in the convection, including strong, coherent, downflowing plumes, which can penetrate into the lower stable half of the box.