Research project: Southern Ocean Carbon and Heat Impact on Climate (SO-CHIC)

The Southern Ocean regulates 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.

To contribute to reducing uncertainties in climate change predictions, 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 is an ambitious project with the aim of unlocking understanding of some of the key Southern Ocean processes, which represent the main limitation of the current generation of climate models in their way to represent past and future global heat and carbon cycles. The project proposes to tackle this significant gap in our knowledge of how the climate system operates by bringing together old and new observations, along with new specific modelling efforts developed in different groups within Europe. SO-CHIC's five objectives are:

• To initiate a sustained monitoring of budgets of heat and carbon in the Southern Ocean, by quantifying their fluxes at the air-sea-ice interface and estimating interannual variability of heat and carbon storage in the Southern Ocean.
• To improve understanding of the spatial distribution and variability of heat and carbon exchanges between the atmosphere and the deep ocean, focusing on the dynamics of the ocean mixed-layer, its relation to sea ice distribution, and on assessing what has caused the opening of the open-ocean Weddell Polynya in 2016 and 2017 (i.e. a large-scale ice-free area within closed sea-ice cover), more than 40 years after its previous occurrence.
• To improve understanding of the formation and export of bottom waters in the bottom boundary layer, which ventilate the world ocean’s abyssal layers, and to propose new strategies to represent such key processes, which are major shortcomings of state-of-the-art climate models.
• To identify critical sensitivities in the Southern Ocean climate system that must be correctly represented in models in order to significantly reduce uncertainties in future projections of oceanic heat and carbon content.
• To enable free and open access to all data, and to maximise impact on international climate reports (e.g., IPCC Assessment Reports), climate services, and climate-model groups.

Type of project: EU H2020 grant project

PI: Dr. Jean-Baptiste Sallée (Sorbonne University)
Co-I: Prof. Alberto Naveira Garabato

Funding provider: EU Horizon 2020

Funding dates: 2019-2023