The extent of the solar overshooting zone deduced from Li abundance

Abstract

Using a non-local convection theory for chemically inhomogeneous stars, a set of models of the solar convective envelope is presented in this work. The (7) Li depletion as a result of convective overshooting is calculated. A model for the solar convective envelope is found which meets the observational constraints from both the Li abundance and depth of the convection zone determined by helioseismology. We argue that there is no general overshooting distance that holds for all physical quantities, and the differences between them can be factors of a few. In the case of solar lithium depletion, the effective overshooting distance at the low convective boundary can be extended to 1.07H(P) (where H-P is the local pressure scaleheight at the boundary), while the corresponding super-radiative temperature zone overshoots to 0.2H(P) in the sense of helioseismology, and the e-folding length for turbulent velocity and temperature is about 0.38H(P) for this solar model.