The ICOS Ocean Thematic Centre (OTC) supports a coordinated European observing system designed to deliver the long-term ocean measurements required to understand the present state and predict the future behaviour of the global carbon cycle and climate-relevant gas emissions.
The ocean plays a fundamental role in regulating climate by absorbing approximately 25% of anthropogenic carbon dioxide (CO₂) emissions, thereby mitigating the pace of climate change. However, this uptake also contributes to ocean acidification, with potential impacts on marine ecosystems. Continuous and consistent observations are therefore essential to monitor these changes and their consequences.
A key priority of the ICOS ocean network is the quantification of air–sea CO₂ fluxes, particularly in the Atlantic Ocean, which is central to determining the European carbon budget and improving estimates of terrestrial carbon exchange. At the same time, the system integrates global surface and subsurface measurements to provide a comprehensive understanding of the ocean’s role within the global carbon cycle.
Because marine carbon fluxes vary significantly across regions and over time—from seasonal to decadal scales—long-term, high-quality monitoring is essential to capture variability, identify underlying drivers, and improve predictions of future change under evolving environmental conditions.
Core Objectives of the OTC
The ICOS Ocean Thematic Centre aims to:
- Coordinate the European marine carbon observing network, providing technical and scientific support to ocean stations
- Ensure high-quality, standardised CO₂ measurements through station labelling, training, and rigorous data quality control
- Harmonise data handling and access in collaboration with the ICOS Carbon Portal and international standards
- Produce consistent regional products, including maps of CO₂ sources and sinks across Europe and adjacent seas on monthly to interannual timescales
- Support laboratory analysis and calibration, ensuring traceability and accuracy of oceanic measurements
- Contribute to global observing systems, working with international initiatives such as SOCAT and the wider ocean carbon community
Scientific Impact
Through these activities, the OTC contributes to:
- Improved understanding of the global carbon cycle and ocean–atmosphere interactions
- Better constraints on carbon budgets at regional (European) and global scales
- Enhanced ability to predict future climate change and ocean response
- Reliable, standardised data to support climate policy, reporting, and mitigation strategiesThe ocean network of ICOS (Integrated Carbon Observation System) provides long-term observations of the ocean required to understand the present state and better predict future behaviour of the global carbon cycle and climate-relevant gas emissions. The oceanic sink currently offsets approximately 25% of CO2 emissions from human activities. Quantifying these fluxes for the Atlantic Ocean is critical for determining the European carbon budget and for accurate accounting of land fluxes. Global and subsurface measurements must also be taken into account to assess the role of the ocean in the global carbon cycle.