Abstract
The Ross Sea, including its continental and ice shelf cavity areas, is a crucial part of the Southern Ocean known for its rich biodiversity as well as significant roles in deep water formation and sea-ice production. Over the past 5 decades, notable changes in sea ice, biology, biogeochemistry, and seawater composition have been observed, necessitating further research to understand the driving mechanisms and their ecological and climate impacts. Additionally, future warming in the Ross Sea is expected to influence global sea level rise, ocean circulation, and the regional carbon cycle, making the study of these processes imperative, especially given the recent and unprecedented low summer sea-ice extent in 2023. The Aotearoa New Zealand Antarctic Science Platform “Project Two: Ocean Mechanics” was designed to provide a comprehensive understanding of the mechanics of the Ross Sea and its future response when mean global temperatures reach 2°C above pre-industrial levels. Here, we synthesize the results of our 6-year project (2019–2025), highlighting the structure and contributions of this cross-disciplinary research on ocean-ice circulation, from the Ross Sea ice shelf cavity and polynyas to the Ross Sea slope and beyond from observations and model results as well as collaborative links. The study concludes with recommendations for a future Ross Sea observatory to address outstanding questions in this dynamic and critical region.