Atmospheric influence of the Australian summer monsoon on Antarctic Sea ice variability over Pacific sector

Abstract The impacts of tropical systems on the interannual variability of Antarctic sea ice have garnered significant attention. However, most previous studies have primarily focused on teleconnections from the oceans to Antarctica, with relatively limited exploration of the influence of atmospheric variability. This study investigates the relationship between Antarctic sea ice and Australian summer monsoon (AUSSM) rainfall. Both observational analysis and model simulations reveal that the diabatic heating associated with December–February (DJF) AUSSM precipitation triggers southeastward Rossby wave propagation. This wave propagation leads to the development of anomalous barotropic high‐pressure systems over the South Pacific sector of the Southern Ocean, including the Ross and Amundsen Seas. These atmospheric anomalies affect surface downwelling long‐wave radiation and winds, thereby influencing sea ice variability through both thermodynamic and dynamic processes. Understanding the role of the AUSSM in driving Antarctic sea ice variability, independent of concurrent sea surface temperature anomalies, offers potential for enhancing predictions of Antarctic sea ice extent changes.