Fig. 8.

Temporal evolution of the partial surface pressures $P_{\mathrm{surf}}$ of H, O, and C normalized to the total initial surface pressure $P_{\mathrm{total}}$ for the four compositions of outgassed atmospheres described in Table 2. The hydrogen inventory evolves assuming a constant escape rate and parameters according to CII in Table 3 valid for 100 XUV. Both O and C are dragged along with the escaping H.