CAPTURE · Carbon pathways in the Southern Ocean
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2021-01-01 → 2024-01-31
- EU contribution
- €281,827
- Participants
- 2
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Carbon pathways in the Southern Ocean
The Biological Carbon Pump (BCP) transfers atmospheric CO2, fixed by phytoplankton in the sun-lit upper ocean, as particulate organic carbon to the deep ocean. The BCP plays a key role in Earth’s climate by removing 10 Pg of carbon from surface waters each year, with the Southern Ocean (SO) pump representing 33% of the global BCP. Carbon export from the BCP has long been solely attributed to the gravitational sinking of large particles following the spring phytoplankton bloom. Conspicuous imbalances in ocean carbon budgets have recently challenged this long-lived paradigm. Several lines of observational evidence have demonstrated the importance of additional export pathways that transfer all classes of particles to depth with different seasonality. Physical transport of organic matter by vertical mixing or active transport by zooplankton vertical migration should now be considered as major export pathways contributing to the BCP. CAPTURE (CArbon PaThways in the soUtheRn ocEan) aimed at developing a mechanistic and quantitative understanding of the BCP export pathways using year-round and depth-resolved observations from heavily instrumented Biogeochemical Argo floats (BGC-Argo). The project was organised around three work packages (WP): • WP 1: Phytoplankton seasonality. How Environmental factors control phytoplankton seasonality in contrasting bio-regions of the SO? • WP 2: BCP seasonality. How environmental factors and phytoplankton seasonality control the seasonal evolution of the BCP export pathways? • WP 3: Zooplankton seasonality. How the coupling-decoupling between phytoplankton and zooplankton seasonality influence the functioning of the BCP? The main conclusions are: (1) Despite contrasting productivity regimes in the SO, environnemental forcing such as wind stress play an equally important role on phytoplankton seasonality. (2) This seasonality in environmental forcing and phytoplankton biomass controls the seasonality of the BCP which is characterised by a succession of different C export pathways, resulting in a longer and sustained transfer of C to the ocean"s interior than previously recognised. (3) Zooplankton play a central role in the functioning of the BCP, mostly by controlling the efficiency of the C transfer trough vertical migration, aggregation/fragmentation processes and predator-prey relationship.
Data: CORDIS, © European Union
Project objective
The Biological Carbon Pump (BCP) transfers atmospheric CO2, fixed by phytoplankton in the sun-lit upper ocean, as particulate organic carbon to the deep ocean. The BCP plays a key role in Earth’s climate by removing 10 Pg of carbon from surface waters each year, with the Southern Ocean (SO) pump representing 33% of the global BCP. Carbon export from the BCP has long been solely attributed to the gravitational sinking of large particles following the spring phytoplankton bloom. Conspicuous imbalances in ocean carbon budgets have recently challenged this long-lived paradigm. Several lines of observational evidence have demonstrated the importance of additional export pathways that transfer all classes of particles to depth at different times of the year. Physical transport of organic matter by vertical mixing or active transport by zooplankton vertical migration should now be considered as major components of the BCP. CAPTURE (CArbon PaThways in the soUtheRn ocEan) aims at developing a mechanistic and quantitative understanding of these BCP components using year-round and depth-resolved observations from heavily instrumented Biogeochemical Argo floats. We will address the interlinking of these components over complete annual cycles, introducing the novel concept of BCP seasonality. This multidisciplinary approach, combining physical oceanography, phytoplankton and zooplankton ecology and biogeochemistry, will fundamentally change our understanding of key climate-related processes and help close ocean carbon budgets. By providing a synoptic vision of the biogeochemical state of the SO and its capacity to store atmospheric CO2, CAPTURE will address a major societal challenge and assist decision-makers. The transfer of knowledge between all partners of this project, from both academic and industrial sectors, will enhance European scientific excellence and career prospects of the applicant.
Original text from CORDIS.
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Data: CORDIS, © European Union