Fig. 4: Composite differences based on model high-latitude blocking (storm track activity, zonal wind, SST and SST gradient).
From: Decadal predictability of North Atlantic blocking and the NAO
a The standard deviation of the high-frequency geopotential height anomaly at 500hPa (indicating stormtrack activity, see Methods) for CESM-DPLE. The dashed contours show the model climatology for winter (DJFM), while the color shading shows the composite difference of the respective anomalies based on winters of high (top 10%) and low (bottom 10%) ensemble-mean HLB. b: as in a but for the zonal wind at 850hPa (indicating the eddy-driven jet). c: as in a but for the SST anomalies in the preceding autumn (SON). This pattern, resembling the AMV, is referred to as PHLB. d: as in c but for the magnitude of the SST gradient with the black solid line representing the climatological position of the SST front. In each map, the white contours correspond to the respective anomalous field (anomalies added to climatology). Statistical significance is indicated by dots (see “Methods”).
