Antarctic ecosystems and sea ice

The Antarctic environment has shown dramatic recent change and substantial future sea ice loss is projected. Sea ice exerts a large influence on marine ecosystems around Antarctica. In this talk we explore relationships between sea ice and ecosystems and how these evolve across timescales, including the emergence of long term changes, robust relationships between sea ice and marine productivity, and the initial-value predictability of sea ice and associated ecosystems. We find that the negative relationship between spring sea ice and marine primary production is maintained under future warming, but the area of the Southern Ocean under sea ice control is reduced. Further, polynyas continue to be important hotspots of productivity. Warming-induced changes in top predators (fish and penguins) in the Antarctic ecosystem emerge from historic variability earlier than sea ice lower trophic levels. These changes are amplified in Eastern Antarctic regions while Ross and Weddell Seas act as potential refugia for the Antarctic ecosystem. For short-term predictability, we find that Antarctic sea ice is more predictable in winter than summer, driven by SSTs anomalies, but has a large regional dependence. Predictability in sea ice lends predictability to NPP, further highlighting the critical role of sea ice in the Antarctic ecosystem.