Fig. 1: Observed time-varying ENSO residuals and its impact on Southern Hemisphere zonal winds.
From: Southern Ocean heat buffer constrained by present-day ENSO teleconnection
a The difference in SST anomalies between El Niño and La Niña since 1948. The El Niño and La Niña events are defined using the Niño3.4 index (5˚S-5˚N, 170˚W-120˚W) averaged over the ENSO peak season (December, January, February, DJF) when it is greater than 0.75 standard deviation (s.d.). b A comparison between Niño3.4 index and its cumulative index as indicated by bars and curves, respectively. The cumulative Niño3.4 index is calculated only using ENSO events defined as when magnitude of Niño3.4 is greater than 0.75 s.d. (purple), 0.5 s.d. (red), and using all events (blue). c Regression pattern (in units of N m−2 s.d.−1) of zonal averaged zonal wind anomalies onto Niño3.4 index as interannual teleconnection (black line), and regression pattern (in units of N m−2 s.d.−1) of cumulative zonal wind anomalies onto cumulative Niño3.4 index (dashed lines) when Niño3.4 magnitude is greater than 0.75 s.d. (purple), 0.5 s.d. (red), and using all events (blue). d The climatological zonal averaged zonal wind (N m−2). The orange shade indicates the region of climatological westerly wind belt. The SST and zonal wind anomalies are both quadratically detrended before analysis. The ENSO residual induced teleconnection which could rectify on the decadal-to-interdecadal long-term mean climate is similar to interannual ENSO teleconnection pattern in observation.
