Topographic Anchoring and the “Silent Period” of Deep‐Water Polynyas in the 90°W–90°E Antarctic Sector

Abstract Antarctic deep‐water polynyas act as critical windows driving deep ocean ventilation, exerting profound impacts on the global thermohaline circulation and biogeochemical cycles. Utilizing high‐resolution satellite remote sensing and ocean reanalysis data from 2003 to 2022, this study identified eight recurring deep‐water polynyas within the Antarctic 90°W–90°E sector, revealing that their spatial distribution is strictly anchored to prominent topographic features such as seamounts, ridges, and fracture zones. Through a comprehensive multi‐scale analysis, we propose a conceptual “Heat Reservoir‐Transport‐Mixing” framework, demonstrating that oceanic heat transport, topographic steering, and mesoscale eddies constitute the physical basis for maintaining these deep‐water polynyas. Notably, we introduce the concept of the “Silent Period,” reshaping current understanding of the polynya life cycle. This study not only provides a novel perspective on the multi‐scale dynamics of the Antarctic sea ice system but also offers critical observational constraints for improving the parameterization of polar processes in climate models.