Summary of the Na abundance estimates using the IHUA model. Because our approach is local we can only identify here the decreases in sodium abundance by a factor of about 4 at 3 × 10^-5 bar (dot-dashed line), although NLTE effects could perturb that estimation (see text). The drop in abundance by about a factor of 10 showed at the condensation level (at 3 mbar, tripled-dot-dashed line) is taken from Sing et al. (2008a,b).