About
Summary
Ocean carbon is one of only two observational constraints within global carbon assessments. The OC4C project aims to initiate preliminary activities towards the long-term generation of ocean carbon Climate Data Records (CDRs) which will provide and use multiple Essential Climate Variables (ECVs).
Our objectives are to improve, advance and further constrain current estimates of the uptake of atmospheric carbon dioxide (CO2) and its exchange with the ocean (air-sea CO2 fluxes), and to fully characterise and reduce the uncertainties of these estimates. Within this, we will generate a global climate quality time series dataset of ocean carbon air-sea CO2 fluxes which will provide an estimate of the ocean carbon sink from 1980 to present day. This effort involves a diverse group of internationally recognised ocean carbon scientists from across the community.
Project background
Observation-based estimates of the annual ocean carbon uptake (sink) have now become a key component within global carbon budget assessments used to guide policy. Ocean and atmosphere observations form the two key observational pillars and constraints within these annual carbon budget assessments, with their uncertainties directly impacting the closure of the total budget. The policy relevance of these annual carbon assessments cannot be underestimated; they provide information about the impact of mitigation policies and they also enable updates on the so called “remaining carbon budget”, which identifies how much CO2 can be emitted in the coming decades without overshooting specific climate targets. Thus, efforts to increase understanding of, as well as improve the quantification of the ocean carbon sink, will strengthen its constraint on the remaining components of the budget within annual assessments, and increase the strength of any resulting policy guidance.
Aims and Objectives
The aim of the OC4C project is to improve our understanding of the physical and biogeochemical aspects inherent to the ocean carbon uptake, and how they are related to the climate change, both on a global and regional basis. To achieve this, the work on this project sets out to address eight key objectives. These are to:
- Improve and upgrade the state-of-the-art Earth observation (EO)-based estimation of carbon fluxes through the assessment of different reference SST (at their related ocean depths), and refine the ocean carbon fluxes uncertainty estimates.
- Improve and upgrade the state-of-the-art EO-based estimation of carbon fluxes through the assessment of the relevance of marine biology, and refine the ocean carbon fluxes uncertainty estimates.
- Begin to reconcile/recalibrate the currently diverging Global carbon Budget (GCB) model estimates with these upgraded EO Carbon sink datasets.
- Explore carbon sink variability in relation to climate indexes (e.g., ENSO) occurrence and phasing.
- Assess carbon sink variability at different temporal scales (seasonal, inter-annual) and in challenging ocean basins (e.g. the Arctic Ocean)
- Perform a model versus EO sampling sensitivity analysis to assess the inherent sampling-driven differences.
- Provide both global and regional estimates; for the latter, assess the options for regionalization (extrapolation, downscaling, etc.) and the guidance provided by biogeochemical provinces and biomes.
- Draft a scientific roadmap for channelling the relevant upgraded EO carbon fluxes estimates for the future wider context of Global Stocktake reporting for the Paris Agreement.
Project plan
Professor Jamie Shutler (university of Exeter) is responsible for guiding the project’s scientific and technical activity. Project Manager Ruth Wilson (Space ConneXions Ltd) is responsible for the management and execution of the work to be performed, and for the coordination of the consortium’s work. The project draws on the scientific expertise of the partners, UoE, PML, VLIZ, AWI, LSCE and UC (see image ‘Team Roles’).
The project work is broken down into 6 Tasks. These are:
Task 1: Requirements Baseline
All the available satellite, in-situ and model datasets that serve the scope of the project, together with plans to acquire them will be identified and assessed, along with the best candidate test site for the development of the regional experimental products. A clear description of the added value of the proposed work with respect to existing activities and identification of potential areas for collaboration will also be made.
Task 2: Algorithm Development
Via numerous algorithm updates and assessments of data sources, masks and interpolation schemes, a high quality, global, multi-mission, consistent time-series of relevant ocean carbon datasets within an experimental data package will be generated, for further exploitation and reference by the user community.
Task 3: Validation
Validation metrics will be generated and compared with the accuracy, precision and stability requirements specified in the requirement baseline. Product uncertainties will be characterised, through direct or indirect methods, paying attention to the spatial and temporal representation errors.
Task 4: Impact Assessment and Model Intercomparison
Differences between observation-based and model-based CO₂ flux estimates, and the closeness to which the two estimates come with the inclusion of uncertainties/error bars on the observation-based estimates, will be assessed. The correlation of ocean carbon sinks to major climate indexes (e.g. ENSO) will be evaluated. Modelled pCO₂ data at the same spatial and temporal locations as the in-situ data will be sampled, and the EO-model spatial and temporal consistencies or discrepancies, once devoid of the sampling effect, will be evaluated. GOBMs models at EO spatial and temporal resolution, once devoid of the representation error, will be upscaled and assessed.
Task 5: Scientific Roadmap
Major achievements and related shortcoming/bottlenecks of the project will be assessed for future ocean carbon climatic perspectives, and a community workshop will be hosted.
Task: User Engagement and Outreach
Work shall be complementary with related activities, both within and outside ESA
Team
Professor Jamie Shutler (university of Exeter) is responsible for guiding the project’s scientific and technical activity. Project Manager Ruth Wilson (Space ConneXions Ltd) is responsible for the management and execution of the work to be performed, and for the coordination of the consortium’s work. The project draws on the scientific expertise of the partners below.
The University of Exeter (UoE)
The University of Exeter team are based in the Centre for Geography and Environmental Science, University of Exeter Penryn Campus. They conduct research in human and physical geography and environmental science with expertise covering past, present and future global environmental change, biological and physical oceanography, Earth observation and remote sensing using light aircraft and drones, and sustainable development. The University of Exeter’s Professor Jamie Shutler is responsible for the supervision, steering and coordination of the project’s technical and scientific activity, and is involved in all tasks. Dr Daniel Ford is leading Task 2 (algorithm development).
Project scientific lead: Prof. Jamie Shutler.
Task 2 Lead: Dr Daniel Ford
Space ConneXions Ltd (SCL)
SCL’s core activity is the management of Earth Observation projects on behalf of governmental and international organisations. SCL are providing the overall project management for the OC4C contract, and is responsible for the management and execution of the work to be performed, and for the coordination of the consortium’s work.
Project manager: Ruth Wilson
Support project manager: Sorrel Nelson
Plymouth Marine Laboratory (PML)
PML has one of the largest aquatic remote sensing groups in the world with approx. 35 permanent staff, undertaking research and operational near-real time (NRT) and Delayed Time regional and global EO processing and distribution for a variety of projects including UK NEODAAS, ESA OC-CCI and Lakes-CCI. The PML team contribute to all aspects of the project, but in particular will lead and perform half of the work in task 4 ( Impact Assessment and Model Intercomparison).
PML leads: Dr Shubha Sathyendranath, Dr Gemma Kulk and Dr Lekshmi Krishnakumary
Flanders Marine Institute (VLIZ)
VLIZ has the ambition to push the state of the art in marine carbon observation and data modelling in order to develop a measurement-driven carbon budgets, positioning us amongst the pioneers in marine carbon research on shelf sea systems worldwide. Quantifying sources and sinks of carbon dioxide and other greenhouse gases will serve policy makers in their efforts (e.g. in national climate reports) to report regional carbon budgets as part of the UN-stock take and set ambitious threshold to encourage decarbonization efforts. Vliz will host the mid-term meeting and lead the design and writing the sampling experiment publication within Task 4. They also contribute to tasks 1, 5 and 6.
Leads: Dr Peter LandSchuzter, Dr Alizee Roobaert
The Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI)
AWI conducts multidisciplinary research in the Arctic and Antarctic, as well as in temperate latitudes. AWI also holds a Computing and Data Centre which supports high performance scientific computing used in climate studies. With the AWI Climate Model, AWI researchers have contributed to the Coupled Model Intercomparison Project phase 6 (CMIP6) that informs the Intergovernmental Panel on Climate Change (IPCC). AWI co-lead the design and modelling aspects of one of the sampling experiments within task 4, and will be performing all of the model data extraction and sampling in preparation for one of the task 4 sampling experiments. They also contribute to tasks 1, 5 and 6.
Lead: Dr Judith Hauck, with Dr Sreeush Mohanen
Columbia University
The Columbia University team is based at the Lamont Doherty Earth Observatory, with its campus located in Palisades, NY. Lamont is the scientific research heart of the Columbia Climate School, which was founded in 2020 to develop and inspire knowledge-based solutions and educate future leaders for just and prosperous societies on a healthy planet. Columbia University will design and extract the model data for the second sampling experiment within Task 4, and will also contribute to tasks 1, 5 and 6.
Lead: Professor Galen Mckinley, with Dr Amanda Fay and Dr Thea Hatlen Heimdal
The Laboratoire des Sciences du Climat et de l’Environnement (LSCE)
LSCE researchers have a well-established expertise in ocean carbon cycle and climate change impact studies. Access to high performance computing has allowed the development of global coupled ocean circulation biogeochemical models, as well as of ensemble-based methods for the reconstruction at increased spatial resolution of the global surface ocean carbonate system. Within the Copernicus Marine Environment Monitoring Service, LSCE leads the reconstruction of global surface ocean carbonate system variables, as well as air-sea fluxes of CO2 through a neural-network ensemble approach. LSCE will contribute interpolated data fields to the Task 2 experiments, along with contributing to tasks 1, 5 and 6.