Fig. 9: Differences in the 20-year averaged SAT for September during the hindcast period 2004–2023 (°C).

a Control experiment minus observations, b SIC-only experiment minus observations, c SIC-SIT experiment minus observations, d SIC-only experiment minus Control experiment, e SIC-SIT experiment minus Control experiment. Dotted areas indicate statistical significance based on a two-tailed Student’s t test at the 95% confidence level.