Extended Data Fig. 4: ENSO cycle in the oscillator model.
From: ENSO complexity controlled by zonal shifts in the Walker circulation
a-d, Sketch of the Walker circulation at the four consecutive stages of one ENSO cycle: contracted (La Niña), recharged, expanded (El Niño) and discharged. This is shown for sea surface temperatures (SST) and thermocline depth (TD) represented as in Extended Data Fig. 1. The circulation is entirely determined by the warm pool extent χ that shifts the structures and the basin-wide heat content hM that sets the zonal mean TD, as indicated at each stage of the cycle (blue dashed lines) and for the entire cycle (red lines, years 132 to 135 in Fig. 1)). e-h, Mean state of SST and TD (that is temporal averages computed over the entire simulation, green dashed lines) with total fields from a-d repeated (gray fillings). i-l, Sea surface temperature anomalies (SSTA) and thermocline depth anomalies (TDA) at each stage as computed with respect to the mean state.
