24th Pacific Science Congress (PSC-24)

The El Niño–Southern Oscillation (ENSO) is a key ocean-atmospheric mode that affects global weather and climate through atmospheric teleconnections. It remains unclear how robust and stable ENSO teleconnection patterns are under external perturbations. Here, we use observations to demonstrate that volcanic eruptions disrupt ENSO teleconnections with land surface air temperature in boreal summer across the globe. During eruption years, correlations are found to shift in 62.27% of regions where temperature is significantly connected to ENSO during non-eruption years. State-of-the-art Earth System Models fail to capture this disruptive effect, highlighting challenges in simulating the patterns of climate anomalies and extremes under external perturbations. The disruptive effect identified here raises questions about the stationarity assumption in ENSO reconstructions based upon temperature-sensitive proxy records. Our findings call for an improved characterization of regional climate impacts following volcanic eruptions.

El Niño–Southern Oscillation,Volcanic eruptions,ENSO teleconnections,Climate models