Numerical Flow Modeling of Artificial Upwelling

Pathways towards limiting global warming to well below 2°C, as internationally determined in the 2015 Paris Agreement, typically include active Carbon Dioxide Removal (CDR) from the atmosphere in addition to fast and drastic reduction of greenhouse gas emissions. Artificial upwelling of nutrient-rich deep ocean water to the surface ocean is studied as a standalone marine CDR option or in combination with other measures, such as macroalgae farming. This thesis aims to inform the overarching assessment of artificial upwelling in the context of CDR by contributing to a simulation-based evaluation of the techno-economic feasibility and effectiveness of different technical approaches. Motivated by the need to extend and unify the knowledge about different technical options for artificial upwelling, a numerical modeling toolbox for studies on the techno-economic feasibility and effectiveness of artificial upwelling is developed. The numerical methods are based on the open-source framework OpenFOAM® and aim to be generally applicable to studies of buoyant oceanic flow. Throughout the thesis work, the new methods are rigorously verified and validated and subsequently applied in the realm of techno-economic feasibility and effectiveness assessment for artificial upwelling. Three proposed artificial upwelling concepts are studied: propeller-driven, wave-driven, and buoyancy-driven upwelling. While large propeller-driven upwelling devices are found to suffer from the tendency of the cold upwelled water to sink back out of the surface region, the results obtained for wave-driven devices indicate that waves and cross-flow effects can help in keeping the upwelled water suspended. Buoyancy-driven upwelling devices heat the deep ocean water during the upwelling process, thereby avoiding the sinking of the plume at the outlet. As a consequence, buoyancy-driven upwelling has a different cumulative environmental impact profile, which partly contradicts previous assessments of artificial upwelling as a marine CDR measure. The results of this thesis demonstrate how research and development on the technical level affects the environmental impact and overarching assessment of CDR measures. The value of numerical modeling of these effects is thus confirmed.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Christian-Albrechts-Universität zu Kiel

Year

2026

Author dc:creator

• Kemper, Jost

Contributors dc:contributor

• Slawig, Thomas
• Juricke, Stephan

• Carbon Dioxide Removal (CDR)
• mCDR
• Artificial Upwelling
• Numerical Modeling
• Computational Fluid Dynamics (CFD)
• OpenFOAM
• Buoyancy-Affected Flow
• Stratified Flow
• Oceanic Flow
• Scalar Transport
• Heat Transfer
• Mixed Convection
• Interface Tracking
• ALE
• Numerical Wave Tank
• Perpetual Salt Fountain
• Stommel Upwelling Pipe
• Feasibility Assessment
• Open-Ocean Aquaculture
• Macroalgae Farming

Repository record source_url

https://macau.uni-kiel.de/receive/macau_mods_00008351

OAI identifier oai:identifier

oai:macau.uni-kiel.de:macau_mods_00008351