AbstractAbstractExtreme precipitation (EP) exerts an important impact on Antarctic mass changes and consequent global sea level changes. However, its drivers and remote influences remain insufficiently understood. Validation against in situ observations shows that ERA5 reanalysis robustly captures Antarctic EP events. Using ERA5, we examine the spatiotemporal variability in annual and seasonal Antarctic EP from 1979 to 2022 and explore the underlying mechanisms involving atmospheric rivers (ARs) and large-scale circulation modes. Antarctic ice sheet (AIS)-averaged EP intensity and frequency have increased significantly since 1979, with strong seasonal and regional contrasts linked to the Southern Annular Mode (SAM) and the two Pacific–South American (PSA1 and PSA2) patterns. AR landfalls contribute 53.4% of annual EP totals and explain 72% of interannual EP variability. Notably, large-scale EP events affecting > 20% of the ice sheet are preceded by enhanced deep convection over the tropical western Pacific (TWP). This tropical heating anomaly generates upper-level divergence that excites stationary Rossby wave trains. The resulting wave responses project onto zonal wave 3 (ZW3) and zonal wave 4 (ZW4) circulation patterns over the Southern Ocean, establishing multiple meridional moisture corridors toward Antarctica, thereby intensifying AR activity and promoting large-scale EP occurrence. These findings underscore ARs and tropical–polar teleconnections as critical drivers of Antarctic hydroclimatic variability, with implications for ice sheet mass balance projections.
