Séminaire : Lester Kwiatkowski (LOCEAN): Advances in our understanding of ocean acidification across spatiotemporal scales
Wednesday 04 December 2019, 11:00am - 12:00pm
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Abstract : The uptake of carbon by the oceans affects marine chemistry via ocean acidification, a process that increases concentrations of CO2, H+ and HCO3-, and reduces levels of pH and CO32-. These seawater chemical properties are of critical importance to various marine ecosystems. Although Earth system model projections of long-term mean pH are well constrained, we have very limited understanding of the corresponding changes in the temporal variability of ocean carbonate chemistry. I will present findings from recent work, which shows that the amplitude and phase of ocean chemistry seasonal cycles can be dramatically influenced by climate change. During this century, if atmospheric CO2 continues to increase, the seasonal amplitude of pCO2 and [H+] is projected to nearly double in typical surface waters of the ocean, with contrasting and regionally variable changes in other carbonate chemistry parameters such as pH and Ωarag. In the Arctic Ocean, where acidification is projected to be most severe, I will present evidence that Earth system models may still be underestimating the future anthropogenic carbon inventory and associated extent of acidification. Alongside this I will show how the seasonal cycle of Arctic Ocean pCO2 may be in near antiphase with that presently observed by the end of the century under a business-as-usual emissions scenario.
Location salle de réunion LOCEAN, tour 45/55, 4eme étage