Impacts of Eastern and Central Pacific El Niño‐Southern Oscillation on Antarctic Extreme Precipitation Occurrences

ABSTRACT This study investigates the impacts of two types of El Niño—Eastern Pacific (EP) and Central Pacific (CP)—on extreme precipitation occurrences across Antarctica over the 1979–2023 period. While the main analyses focus on the austral cold (May–October) and warm (November–April) seasons, the study also examines the seasonal variations in extreme precipitation across all four austral seasons—summer (DJF), autumn (MAM), winter (JJA), and spring (SON)—to facilitate comparison with previous studies. Analysing data from a global reanalysis (ERA5), a regional climate model (RACMO2) and a general circulation model (CESM2), the study highlights significant seasonal and spatial differences in extreme precipitation occurrence associated with EP and CP El Niño events across Antarctica. EP El Niño exhibits a broader and more substantial influence on the magnitude and spatial extent of extreme precipitation anomalies compared to CP events, with both types showing their most pronounced impacts during the cold season. In that season, both EP and CP El Niño events are associated with positive extreme precipitation anomalies over the Ross Sea and Marie Byrd Land and negative anomalies over the Bellingshausen Sea and the Antarctic Peninsula. EP El Niño also produced marked negative anomalies over East Antarctica (60°–90° E) and positive anomalies over Dronning Maud Land and the southern Atlantic Ocean, whereas such anomalies are minimal or absent during CP events. In the warm season, EP El Niño generates a dipole pattern, with positive anomalies over the Amundsen and Ross Seas and negative anomalies over the Weddell Sea and Dronning Maud Land, a structure that is significantly weakened for CP events. These differences are attributed to distinct upper‐tropospheric wavetrains, driven by positive tropical Pacific and Indian sea‐surface‐temperature (SST) anomalies, which modulate water vapour flux and vertical velocity across the Antarctic continent.