My contribution to scientific research concerns the climate / biogeochemical cycles feedbacks, through studies of the temporal evolution of the atmospheric concentration of greenhouse gases (GHG), using ice cores and interstitial air in polar firn.
I mostly studied these feedbacks through the reconstruction of temporal trends for mixing ratios and some isotopic ratios of GHG such as methane (CH4), carbon dioxide (CO2), nitrous oxide (N2O), ozone (O3) and some organo-halogenated compounds, but also of carbon monoxide (CO) which plays a major role on atmospheric chemistry. In another field of research, I have explored the state and dynamics of the climate system in the past, by initiating the use of global changes in atmospheric CH4 as a chronological constraint or to constrain climatic and glaciological parameters (temperature and accumulation in Antarctica, chronology of trapped gases in polar ice). Lastly, the last years have seen me investing into a new field : instrumental oceanography and process studies in the ocean through the in-situ and high resolution analysis of dissolved gases, and associated investigations of marine processes.
My research activity is dominated by instrumental and analytical work, including for instant the set-up and development of isotope geochemistry at LGGE in the mid 90s. 14 years ago, I also launched the application of new laser optical spectroscopy techniques on trace-gas analyses in ice cores.
I also contributed to modelling activities, with essentially a new major theme every 10 years. I started with modelling methane sources at different time scales. Then I contributed to a specific approach on the spatial distribution of wetlands. More recently I contributed to the use of a model of intermediate complexity to evaluate the role played by permafrost on the carbon cycle during the Quaternary era.
The main breakthroughs that one could extract from this activity can be summarized as :
In terms of research management, my involvement largely increased since 2003 :
From 2018 to 2022, most of my time was devoted to the position of Executive Director of the French polar institute Paul-Emile Victor (IPEV). I was also been nominated during that time as Project Manager for Polar Affairs, attached to the science directorship of CNRS. Since July 2021, I act as Chairman of the Ice Memory Foundation.