Fig. 5: Tropospheric mechanisms of the early-winter ENSO teleconnection to NAE.

Composites for La Niña (a, c, e) and El Niño (b, d, f) of ND Z200 anomalies (contour lines; dgpm) and wave activity flux (WAF; see Methods) (vectors; m2s−2). The anomalous Rossby wave source (RWS) term corresponding to the advection of absolute vorticity by the anomalous divergent wind at 200 hPa is shown with shading, only in the regions where it is significant at the 95% significance level. Results are plotted for the periods a, b P1, c, d P2 and e, f P3.