T. Moutin & H. Claustre, C. Lo Monaco, L. Bopp, I. Xueref-Rémi, D. Lefevre, F. Lemoigne, C. Tamburini (M2S1)
Objective
The aim of this lecture is to lay the foundations for the role of the marine carbon cycle in controlling climate on a global scale by regulating the partial pressure of atmospheric CO2. The course covers the carbon cycle in the surface ocean and water column, the calcium carbonate cycle, glacial and interglacial fluctuations in atmospheric CO2 during the Holocene, and anthropogenic CO2 perturbation (methods for tracing anthropogenic carbon in the ocean).
Map showing annual mean air-sea CO2 partial pressure difference, based on data from Takahashi et al. 2002 (from Sarmiento & Gruber, 2006).
Lectures
1. The carbon cycle in the surface ocean: what factors control pCO2 in the surface ocean (dissolved mineral carbon chemistry – Revelle factor, mean annual distribution – physical and biological control processes, seasonal variability – subtropical gyres, North Atlantic, North Pacific), case study (deep-sea upwelling).
2. The carbon cycle in the water column (notion of pump, biological pumps, solubility or gas exchange pump, model results),
3. The calcium carbonate cycle (formation, processes in the water column – CaCO3 solubility, saturation state, carbonate distribution, dissolution in the water column -, impact of ocean acidification),
4. Anthropogenic CO2 perturbation (the greenhouse effect, glacial-interglacial fluctuations in atmospheric CO2 during the Holocene, global warming, evidence of anthropogenic perturbation). Thermodynamic and kinetic constraints on CO2 transfer between atmosphere and ocean. Penetration of anthropogenic CO2 into the ocean (direct estimates, methods for tracing anthropogenic carbon in the ocean – TROCA method, C* method, Chen and Millero method -, current and future ocean absorption capacity).
Other Interventions
Claire Lo Monaco (CNAP, LOCEAN Paris) previously N. Metzl (same laboratory, DR, Head of SOLAS-IMBER carbon group): “Evolution of oceanic CO2 in the South Indian Ocean (OISO campaigns)”
Hervé Claustre (DR CNRS Villefranche/mer, Chairman of the international Bio-Argo working group. Project leader: Remotely-sensed biogeochemical cycles in the Ocean): “Carbon balances at global, regional and local scales: contribution of sea color remote sensing and instrumented autonomous platforms”
Laurent Bopp (Department Director at ENS Paris): Modeling Marine Biogeochemistry. Applications to climate change
Frédéric Lemoigne (CR CNRS Brest) and Christian Tamburini (DR CNRS Marseille) : “Efficiency of the biological pump in the transfer of matter and carbon in the epi- and mesopelagic zone, Role of dissolved organic carbon in the oceanic carbon cycle”
Dominique Lefèvre (CR CNRS Marseille) : “Biological pump and dissolved oxygen dynamics”
Irène Xueref-Rémi (CNAP, Marseille) : “Assessment of CO2 stocks and fluxes in the atmosphere”