Modeling of the interface between the radiative zone an the convective zone. r_b corresponds to the radius at the base of the convective envelope as given by the Schwarzschild’s criterion, L_p is the penetration length over which the plume is decelerated and generates waves, d denotes the extent of the transition region (where the plume velocity is negligible compared to V_b, its value at the entry of the penetration region) and r_d is the radius at the top of the radiative zone.