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VERTical EXchange in the Southern Ocean

Project description

Southern Ocean vertical exchange

Historically, the global ocean has played a critical role in mitigating global climate change by taking up most of the excess heat and about 30 % of the anthropogenic CO2 emissions from the atmosphere. The greatest part of this process occurred through the renewal of subsurface waters in the Southern Ocean. However, global climate models still fail to represent the region’s past climatic changes, leading to significant uncertainties in future projections. The EU-funded VERTEXSO project will study vertical transport processes in observations and model simulations, with a particular focus on convective plumes. VERTEXSO will improve the representation of vertical transport processes in models, assess their impact on vertical heat and carbon exchange, and develop innovative methods to monitor them.


Mitigating global climatic changes due to human influences is of paramount importance in the coming decades. Historically, the global ocean has played a critical role in this process by taking up the majority of the excess heat and about 30% of the anthropogenic carbon-dioxide (CO2) emissions from the atmosphere. The largest share of this uptake process occurred through the subduction of waters in the Southern Ocean that sequester heat and carbon in deeper layers of the ocean. Yet, global climate models have their largest biases in this region and difficulties in representing its past climatic changes. Thus, their future projections bear large uncertainties in the potential of the Southern Ocean to continuously provide such a mitigation service. VERTEXSO addresses this challenge by studying vertical transport processes, improving their representation in models, and developing novel methods to continuously monitor the vertical exchange. In order to reach these goals, this project performs simulations with a regional ocean model that is able to directly resolve convective plumes and assesses their impact on vertical carbon exchange. We then scale the insights to a global level by improving parameterisations of vertical processes in an Earth System Model, and by investigating their impacts on global climatic changes. Facilitated by most recent advances in remotely observing the Southern Ocean high latitudes, we explore tracers of convective plumes in subsurface data and integrate these observations with satellite data to assess surface density stratification changes. The latter forms a new measure for vertical exchange that serves as a benchmark for model simulations and a tool to monitor the potential of the Southern Ocean to take up and release CO2 and heat. Through this combination of observational data with multi-scale model simulations, VERTEXSO advances the understanding of vertical exchange in the Southern Ocean and how its changes affect the global climate.

Host institution

Net EU contribution
€ 763 477,75
27570 Bremerhaven

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Bremen Bremen Bremerhaven, Kreisfreie Stadt
Activity type
Research Organisations
Total cost
€ 763 477,75

Beneficiaries (2)