Southern Indian Ocean climate evolution and its global linkages

ended

IPCC RCP projections indicate that Earth’s temperature will increase by 1-5°C by 2100, mainly in response to increasing anthropogenic CO2 and GHG emissions. Warming will particularly affect polar oceans (e.g. Southern Ocean (SO)) that uptake most of the anthropic CO2. Such unprecedented changes in the SO will in return strongly impact ocean-atmosphere gas exchange (lower CO2 uptake), SO-sourced ocean circulation (lower nutrient stocks) and marine biological production/diversity (lower phytoplankton stocks) through high-low latitude teleconnections, with strong repercussions on the global economy. However, RCP scenarios are mainly constrained by observational data that are too short in time to cover the full range of climate variability and, thus, to confidently forecast climate change. In this vein, the SO-Link project aims to investigate past oceanic conditions (sea-surface and deep ocean temperatures, ocean circulation, nutrient stocks) and biological variations (phytoplankton productivity and physiological state) in warmer-than-present mean climate states of the Plio-Pleistocene, as analogs of future conditions. To this goal, readily available and well-preserved sediment cores collected in 2019 in the Indian sector of the SO will be used. Innovative quantitative, geochemical and elemental investigations will be implemented on the two SO dominant phytoplankton groups (calcareous coccoliths and siliceous diatoms), based on the expertise of the applicant and host, respectively (at UBx). This knowledge is considered high priority by SCAR, IPCC, Horizon Europe, and UN Framework Conversion of Climate change, and it is in line with UN Decade of Ocean Science of the sustainable development program. The SO-Link project is of clear scientific, societal and policy relevance and will provide stakeholders (Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) for example) with unique information for comprehensive protection of SO biodiversity.