ENSO-driven extreme heat propagation: network topology and pathways across El Niño, La Niña, and neutral phases

Abstract The El Niño–Southern Oscillation (ENSO) modulates global heatwave propagation through teleconnections, yet its phase-dependent control over spatiotemporal connectivity remains unclear. Here we develop a multi-scale climate network framework integrating geographic thresholds (2500 km) and directional event synchronization to quantify ENSO’s dual regulation of short- and long-range heatwave linkages across the Pacific–Indian Ocean domain. Analyses of 1979–2023 reanalysis data reveal El Niño amplifies trans-Pacific heatwave synchronization by 60% compared to neutral conditions, driven by Rossby wave trains facilitating >4000 km propagation. Conversely, La Niña confines heatwave propagation to regional scales through persistent anticyclonic circulation patterns, suppressing inter-basin linkages by 40% as regional systems prevent trans-oceanic propagation. Network topology shows El Niño’s bimodal distance distribution (peaks at 1000 km and 3000–4000 km) versus La Niña’s exponentially decaying pattern. Dynamical analysis links these patterns to phase-locked 850 hPa geopotential anomalies, demonstrating ENSO’s scale-selective control over extreme heat propagation.