Fig. 5: Water-mass transformation rates in Control and warmer climate simulations.

Thirty-year climatological winter season (June–September) water-mass transformation rates driven by total surface flux in the a Prydz, b Adélie, c Ross, and d Weddell polynyas in the (black) Control, (orange) 2×CO2, and (red) 4×CO2 simulations. The water-mass transformation rates are calculated over the polynya regions from the Control simulation (green lines in Fig. 1c–f).