Fig. 6.

CO₂ concentration and leakage. (a) Concentration of CO₂ in the cell centre relative to the external dissolved concentration (i.e. the concentration of dissolved CO₂ in equilibrium with air at standard atmospheric pressure and 20 °C, c_C (r=0)/c_Ceq, as a function of r_i and r_v–r_i. (b) CO₂ leakage from the cell core as a proportion of the C₄ pump current. The optimal-geometry line is marked light-blue. Other lines are as in Fig. 3. Parameters are as in Fig. 2.