Upward Overshooting in Turbulent Compressible Convection. II. Simulations at Large Relative Stability Parameters

Abstract

Abstract In this paper, we present the results of three-dimensional numerical simulation of upward overshooting in turbulent compressible convection at large relative stability parameter S. Similar to the previous simulations at small S, we find that the convectively stable zone can be partitioned into three layers: the thermal adjustment layer, the turbulent dissipation layer, and the thermal dissipation layer. Despite of this similarity, there exist significant differences in several aspects. First, for small S, the thermal structure is altered considerably near the interface between the convectively unstable and stable zones. For extremely large S, the thermal structure is only slightly changed. Second, the overshooting distance decreases at small S, but it can increase when S is large enough. Third, for small S, the fluid motions tend to be less active when S increases. However, the fluid motions can be more active when S is large enough. We find that the structure of counter cells has a significant impact on the penetration depth.