The Southern Ocean regulates the global climate by controlling heat and carbon exchanges between the atmosphere and the ocean. Rates of climate change on decadal time scales ultimately depend on oceanic processes taking place in the Southern Ocean, yet too little is known about the underlying processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent small-scale processes that are not captured in current Earth system models.
The Southern Ocean regulates the global climate by controlling heat and carbon exchanges between the atmosphere and the ocean. It is responsible for about 60-90% of the excess heat (i.e. associated with anthropogenic climate change) absorbed by the World Oceans each year, and is also recognised to largely control decadal scale variability of Earth carbon budget, with key implications for decision makers and regular global stocktake agreed as part of the Paris agreement. Despite such pivotal climate importance, its representation in global climate model represents one of the main weaknesses of climate simulation and projection because too little is known about the underlying processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent small-scale processes that are not captured in current Earth system models.
To contribute to reducing uncertainties in climate change predictions, 15 institutions decided to pool expertise in a common initiative and submit in August 2018 a proposal to the call LC-CLA-08-2018 “Addressing knowledge gaps in climate science, in support of IPCC reports” as part of the European Union’s Horizon 2020 research and innovation programme. This proposal received funding from the programme and is starting on November 1, 2019 for 4 years. The SO-CHIC (Southern Ocean – Carbon and Heat Impact on Climate) project is born.
The overall objective of SO-CHIC is to understand and quantify variability of heat and carbon budgets in the Southern Ocean through an investigation of the key processes controlling exchanges between the atmosphere, ocean and sea ice using a combination of observational and modelling approaches. SO-CHIC considers the Atlantic sector of the Southern Ocean as a natural laboratory both because of its worldwide importance in water-mass formation and because of the strong European presence in this sector already established at national levels, which allow to best leverage existing expertise, infrastructure, and observation network, around one single coordinated overall objective. SO-CHIC also takes the opportunity of the recent re-appearance of the Atlantic Sector Weddell Polynya to unveil its dynamics and global impact on heat and carbon cycles. A combination of dedicated observation, existing decades-long time-series, and state-of-the-art modelling will be used to address specific objectives on key processes, as well as their impact and feedback on the large-scale atmosphere-ocean system.