Fig. 4: Fourth coupled pair of global SST (ERSSTv5) and Arctic SIC, T2M, and SLP (ERA5) October–March anomalies from 1950 to 2024.

The SST spatial structure of the fourth CCA pair (a), explaining 9.7% of variance, together with coupled Arctic SIC (c; 4.0% of variance), T2M (d; 5.0% of variance), and SLP (e; 10.9% of variance) fields north of 50° N for SIC and T2M, and north of 40° N for SLP. The correlation between their corresponding time series (b) is 0.89. Their correlation with the Niño3 Index (red line) is 0.54 (95% confidence level).