Time evolution of quantities that describe the dust settling process against the emergence of VSI turbulence. From top to bottom these are the ratio of dust-to-gas scale height, the mid-plane dust-to-gas density ratio, the root mean squared mid-plane vertical gas velocity, and the root mean squared (rms) vertical Reynolds stress. The left panels compare different metallicities with fixed τ₀ = 10⁻³, while the right panels compare different Stokes numbers τ₀ with Z = 0.01. The dashed red lines in the panels of rms(v_gz0) are the exponential that describes the predicted linear growth of VSI-related velocity perturbations for an isothermal dust-free gas (Nelson et al. 2013).