Fig. 4: SEA of ΔSLP reconstruction, with volcanic eruption years as defined in ref. ³⁵ (with one exception; see text).

SEA averages the n volcanic eruptions events to provide a composite ΔSLP response to explosive volcanism. Bars show the proportion of the 4,800 ΔSLP reconstruction ensemble members that have a significant³⁷ positive (La Niña-like) or negative (El Niño-like) ΔSLP anomaly in the −3 to +6 years relative to each eruption composite (see Methods). Thin grey lines show composite ΔSLP anomalies for 100 randomly chosen ensemble members. Grey–blue envelopes show associated confidence intervals, calculated using random bootstrapping³⁷. Vertical black line highlights the eruption year (year 0). a, All eruptions with SAOD ≥ 0.05 that intersect the 1200–2000 ΔSLP reconstruction (n = 25). b, As per a but only the 18 most recent volcanic eruptions with SAOD ≥ 0.05 (1585–2000). c, As per a but only the 12 most recent volcanic eruptions with SAOD ≥ 0.05 (1762–2000). d, As per a but only the six most recent volcanic eruptions with SAOD ≥ 0.05 (1862–2000). Significant (P < 0.05) responses are determined using a double-bootstrap approach³⁷. Colour blocks on each bar show the proportion of significant responses from ensemble members calculated using each reconstruction method.