Top: the maximum convective turnover time to sinking time ratio, τ_conv/τ_sink, for a hydrogen-dominated-atmosphere white dwarf (abbreviated as DA). The different colored curves show this ratio at various magnetic field strengths ranging from B = 10⁴ to 10⁸ G, and the horizontal dashed line shows where the ratio is unity. When the ratio is much less than order unity, the atmosphere is well mixed. τ_conv is calculated from Equation (21) with the atmosphere convective flux, scale height, and density calculated by MESA. The metal diffusion timescale at the bottom of the convection zone τ_sink is measured by MESA. Quantities calculated in MESA assumed a regular convection zone with ML2/α = 0.8 (E. B. Bauer & L. Bildsten 2019). The rotation rate Ω is set by the rotation period P, which is chosen to be 2 hr, consistent with many magnetic white dwarfs (M. S. Hernandez et al. 2024). Note that for hydrogen-dominated-atmosphere white dwarfs, when T_eff > 12,000 K, the atmosphere becomes fully radiative. Bottom: same as the top panel except for a helium-atmosphere white dwarf (abbreviated as DB), where the convection zone is simulated with ML2/α = 1.25 (D. Koester et al. 2020).