Modelling the convection zone

We examine the sensitivity of the depth of the CZ to mass, stellar abundances, and input physics, and in particular, the use of a measurement of the acoustic depth to the CZ as an atmosphere-independent, absolute measure of stellar metallicities.

We find that for low-mass stars on the main sequence with 0.4M_{sun}_<=M<=1.6M_{sun}_, the acoustic depth to the base of the CZ, normalized by the acoustic depth to the center of the star, {tau}_cz,n_, is both a strong function of mass, and varies at the 0.5%-1% per 0.1 dex level in [Z/X], and is therefore also a sensitive probe of the composition. We estimate the theoretical uncertainties in the stellar models and show that combined with reasonable observational uncertainties we can expect to measure the metallicity to within 0.15-0.3 dex for solar-like stars.