Tribute to Prof. Matthieu Roy-Barman

It is with deep sadness that we announce the passing of Prof. Matthieu Roy-Barman on 19 March 2021 as a result of a heart attack. Please find below a tribute prepared by Catherine Jeandel:

Matthieu was an exceptional professor at the University of Versailles Saint Quentin (France). Much appreciated by his students, he also assumed many administrative responsibilities while conducting particularly innovative research in marine geochemistry. He had also conceived and accomplished the publication of the book “Marine Geochemistry“: as co-author, I can testify of the major investment that Matthieu put in this work.

Matthieu has also been an invaluable contributor to GEOTRACES, participating in intercalibration exercises, cruises… and pushing the interpretation of the results in the most precious details to quantify the processes. His articles testify of the power of coupling reliable geochemical data with modelling, which allowed him to describe particle dynamics with remarkable finesse (e.g. influence of isopycnal transport in the Southern Ocean, specific dynamics in the Mediterranean Sea…). As a specialist in thorium and protactinium analyses, two key parameters of GEOTRACES, he did not hesitate to take the risk of developing the measurement of actinium by mass spectrometry, with success, even though this tracer is present in minute concentrations in the ocean (10-18 moles/l). This isotope has the property of tracing vertical diffusion up to 2000 metres above the ocean bed, which is so slow and diffuse that no physical measuring instrument can quantify it, even though this parameter is essential for ocean models. Matthieu and his student Martin Levier have managed the feat of measuring actinium and its father protactinium by mass spectrometry on only 10 litres of seawater instead of the hundreds of litres required for its detection by radioactive counting, which is also very time-consuming. Such progress has led Hélène Planquette and I to include this tracer in the range of samples of the French GEOTRACES SWINGS cruise (2021). Matthieu took risks and took the time to challenge, process and dissect them, which is particularly rare and precious at a time when the number of publications counts more than their profundity. Marine geochemistry has lost a creative researcher who did not shy away from any analytical challenge.

Catherine Jeandel,
on behalf of the GEOTRACES Programme.

Those colleagues willing to contribute to Matthieu’s book of condolences can send their text by e-mail to: livredormatthieu@orange.fr