Fig. 5.

Composite anomalies of Arctic mean LSAT (in degrees Celsius) as a function of the normalized PDV and AMV indices, based on 37 CMIP5 piControl simulations. The PDV index is defined as the principal component of the first EOF for detrended, 8-y low-pass–filtered November–March mean SST anomalies over the Pacific (120°E–70°W, 50°S–60°N). Using the same data, the AMV index is defined as the SST anomaly averaged over the North Atlantic (60°W–0°, equator–70°N). Insignificant composite anomalies at the 95% confidence level are shaded in gray.