Research: Paleoceanography and marine biogeochemistry

Our research aims at better understanding current climate-related issues and predicting consequences of global warming. It is only in the present that we can study Earth processes as they occur. But often due to a lack of information or sometimes due to an excess of it, we rarely know how those processes will unfold tens or hundreds of years from now. Our research is thus directed toward an enhanced appreciation of past variability in the Earth system, which may help us predict future changes.

The geological archive offers a rich array of natural experiments during which the climate and marine ecosystem changed, sometimes abruptly. The overall concept of this project is to investigate the main Southern Ocean processes modulating temporal changes in the marine biogeochemistry, and assess their role in determining atmospheric pCO2. More specifically, the project aims to constrain the interactions between climate and marine biogeochemistry, as mediated by the global scale ocean circulation, gleaned from the testimony of paleoceanographic records. These records extend beyond the noise of recent decadal oscillations, to provide an independent perspective on the links between climate and ocean dynamics.

Our central objective is to develop a deeper insight into the fundamental drivers of the rate at which the Antarctic circumpolar ocean contributes to the partitioning of carbon, nutrients and oxygen between the ocean interior and the polar and (sub)tropical productive surface ocean.

We mainly pursue two main research avenues:

Southern Ocean paleoceanography and glacial-interglacial changes in the global efficiency of the biological pump.

Deoxygenation of the upper ocean on glacial-interglacial timescales – implications for the global nutrient inventory and carbon cycle dynamics.