IMOS · IMaging Ocean Sinkers for evaluating carbon export fluxes

IMaging Ocean Sinkers for evaluating carbon export fluxes

Knowing how Earth will respond to increasing atmospheric CO2 is arguably the scientific question of our era, because all of humanity will be affected. The oceanic Biological Carbon Pump comprises wide-ranging processes that set carbon storage in the oceans’ interior and has a major role in reducing atmospheric CO2 concentrations. Understanding the Biological Carbon Pump therefore allows us to predict the carbon sequestration capacity of the oceans, which will affect future climate. Earth system models (ESMs), including those used by the United Nations Intergovernmental Panel on Climate Change, are key tools for providing climate projections, but their reliability is challenged by the empirically based data on which they rely. Current ESMs pay special attention to the carbon cycle component however, at present, the ocean’s capacity to take up and store carbon via the Biological Carbon Pump is a key uncertainty in our understanding of the global carbon cycle and its response to anthropogenic perturbations. The ultimate purpose of my research is to contribute to better quantifying the role of the oceans in the global carbon cycle. I aim at increasing the precision of the carbon export assessments in the oceans via the Biological Carbon Pump and the description of the key processes controlling it. To that purpose, I use high resolution underwater cameras, UVP (Underwater Vision Profiler) type, for particle imaging coupled to a novel autonomous platform that acts as a sediment trap. I use these experimental results as input parameters for stochastic simulations of particle dynamics in the ocean. My research program is structured around three objectives (O) that I identify as key areas for describing the present and future role of the Biological Carbon Pump in global climate models: - O1) to identify relationships between the optical properties of particles and the biological and mechanical properties of the carbon flux that determine the magnitude of the Biological Carbon Pump, - O2) to quantify key parameters influencing carbon flux and its attenuation with depth as a function of the ecosystem, - O3) to synthesize the results of previous research objectives to propose a novel standard method to reliably estimate carbon fluxes in contrasted ecosystems from particle images obtained with underwater cameras.

Data: CORDIS, © European Union