Model results for the CTRL experiment (upper panels a–d) and differences between the PHYS sensitivity and CTRL experiments (PHYS-CTRL, lower panels e–f), after 500 years of run, for the mean annual sea-surface DIC (mmol m^–3), TA (mmol m^–3), pCO₂ (µatm, the dashed line shows the 278 µatm contour), and CO₂ fluxes (FCO₂, g C m^–2 yr⁻¹) in the Southern Ocean (see Table 1 for characteristics of the experiments). FCO₂ is expressed in g C m^–2 yr⁻¹ for ease of comparison to other values provided elsewhere. The blue line indicates the maximum winter sea ice extent; the textured areas indicate the model grid. For ease of comparison between figures, the color scales used for the PHYS-CTRL differences depicted here are the same as for the PHYS-CTRL differences depicted in Figure 3 for the Arctic Ocean.