BaSIS

Barium (Ba) has been proven to be a particular useful tool to estimate organic carbon remineralization in various areas of the world’s ocean. To date, however, the Ba cycle and its budgets in the ocean are not well constrained. Indeed, in the ocean, sources of Ba from hydrothermal alteration and deep-sea sediments, but also the internal Ba cycle are hard to constrain with Ba concentrations alone. The use of Ba isotopic composition (¹³⁸Ba) measurements can provide meaningful insights on these sources and processes. Specifically, different inputs and different biological processes influencing the Ba distribution in the ocean have distinct ¹³⁸Ba. However, surveys of ¹³⁸Ba, in seawater and particles in the Southern Ocean (SO) has never been made. It is particularly important to understand the impact of the SO on the Ba cycle, as any preformed Ba or other sources of Ba in the SO would have a large impact on its use as a remineralization tracer in the global ocean. BaSIS is thus a unique opportunity to enhance knowledge on the Ba cycling in this key oceanic region by studying ¹³⁸Ba in seawater and marine particles from the GEOTRACES cruise SWINGS in the SO. The fellow will spend the first two years at the Laboratoire de l’Envionnement Marin (LEMAR) under the supervision of Dr. Planquette. This fellowship will allow her to come back to Europe with the technical expertise she acquired outside of the EU in the past years. She will implement a new technic and will acquire a unique overview of the Ba cycle in the global Ocean. Research results will be of interest to worldwide researchers working on the study of the impact of the global carbon cycle, promoting European excellence and competitiveness in dedicated European and international carbon export projects.