A more realistic representation of overshoot at the base of the solar convective envelope as seen by helioseismology

TL;DR

This paper presents a more realistic model of the solar convective envelope's overshoot region, showing improved agreement with helioseismic data by incorporating a smooth stratification transition.

Contribution

It introduces physically motivated models with smooth stratification transitions that better match helioseismic observations compared to previous models.

Findings

Smooth transition models align better with helioseismic data.

Standard models with abrupt overshoot transitions are less consistent with observations.

Physically motivated stratification models improve understanding of the solar interior.

Abstract

The stratification near the base of the Sun's convective envelope is governed by processes of convective overshooting and element diffusion, and the region is widely believed to play a key role in the solar dynamo. The stratification in that region gives rise to a characteristic signal in the frequencies of solar p modes, which has been used to determine the depth of the solar convection zone and to investigate the extent of convective overshoot. Previous helioseismic investigations have shown that the Sun's spherically symmetric stratification in this region is smoother than that in a standard solar model without overshooting, and have ruled out simple models incorporating overshooting, which extend the region of adiabatic stratification and have a more-or-less abrupt transition to subadiabatic stratification at the edge of the overshoot region. In this paper we consider physically motivated models which have a smooth transition in stratification bridging the region from the lower convection zone to the radiative interior beneath. We find that such a model is in better agreement with the helioseismic data than a standard solar model.