Modelling the impact of convective entrainment on the Tropical Tropopause

In the tropics plumes originating near the surface may have sufficient potential energy to overshoot their level of neutral buoyancy. Because of the relatively long radiative relaxation time in the tropopause, such deep convective events, though rare, might have a significant effect on the dynamics/physics/chemistry in the vicinity of the cold point. Indeed recent model simulations and observational studies indicate that convection in the tropics and summertime mid-latitudes influences the temperature and tracer concentrations (particularly water vapor) to altitudes above 16 km. In this talk we will describe the role and robustness of convective overshoot/entrainment in the Tropical Tropopause layer in a 2- and 3D cloud resolving model. We will also discuss the extent and the amount of overshoot as a function of CAPE, geometry, grid resolution, sub-grid scale turbulence parametrisation, domain size and prescribed microphysics.