SARDINE Southern Ocean carbon indices and metrics (SARDINE)

This project will provide a new view of the global impact of the Southern Ocean on carbon and climate metrics, drawing upon the current suite of Earth system models, applying our latest theory and comparing with diagnostics from ORCHESTRA and RoSES activities.

The Southern Ocean is a major ventilation site for heat and carbon exchange, acting as a window connecting the deep ocean and the atmosphere. We need to know how the Southern Ocean is sequestering heat and carbon, and how that uptake is likely to alter with climate change.

We need to understand how the Southern Ocean alters global carbon feedbacks and affects global climate metrics, including how much carbon may be emitted to avoid dangerous climates and meet Paris agreement targets.

We will identify how much carbon is taken up in different water masses by drawing upon ventilation diagnostics from ORCHESTRA and identify the changes in carbon pools, each corresponding to physical, biological and chemical processes.

We will identify the effect of the Southern Ocean on global carbon-cycle feedbacks and key climate metrics by diagnosing Earth system model projections with a 1% annual rise in CO2 as well as those following Representive Concentration Pathways.

Our key climate metrics include identifying the dependence of global surface warming versus carbon emissions, the maximum permitted carbon emission to avoid warming targets and how much warming might occur after emissions cease.

This work is crucial if we are to understand how Southern Ocean circulation and ventilation changes affect global carbon and climate metrics in a warming world.