Fig. 3: Data-simulation comparison of the relationship between Antarctic air temperature and the sea surface temperature difference (ΔSST) between the two Southern Ocean sediment cores.

a The reconstructed ΔSST in comparison with EPICA Dome C (EDC) temperature depicts a horseshoe pattern with its angular point (largest ΔSST) around −4 °C. Red open circles represent data from the late MIS 2 to the end of Termination 1 (10–24 ka), and the red line and arrow represent the temporal progression of ΔSST towards younger ages. Orange open circles represent data from the late MIS 6 to the end of Termination 2 (129–144 ka), and the orange line and arrow represent the temporal progression of ΔSST towards younger ages. b The downcore record of reconstructed ΔSST between MD11-3357 and MD11-3353. c, d Simulated ΔSST between the latitude of MD11-3357 and that of MD11-3353 without ACC shift (green dashed line and solid line) compared with EDC temperature and age. e, f Simulated ΔSST with the best-fitting linear model of ACC shift (dark blue dashed line and solid line) compared with EDC temperature and age. The data in (a) and (b) are plotted semi-transparent in the background of (c–f).