Midplane solid-to-gas ratio of silicate grains (solid lines) and pebbles (dashed lines) at different diffusion strength α_tur and pebble flux F_p/g at effective alpha of α_acc = 3 × 10⁻³. Left, middle, and right panels: results for α_tur = 3 × 10⁻⁴, 10⁻³ and 3 × 10⁻³, respectively. Red, brown, green, blue and black lines represent cases of F_p/g = 0.5, 0.4, 0.3, 0.2 and 0.1, respectively. Silicate grains have the peaks of their solid-to-gas ratios just inside the snow line. This is because the silicate grains initially have the same scale height with that of pebbles and they gradually diffuse vertically to reach the gas scale height (see Eq. (15)).