GEOTRACES Online Seminar Series 2026

The series will run monthly from April to November 2026 (with a break in July), with seminars planned for the last Tuesday of each month. Plus, a special end-of-year Christmas seminar around mid-December.

Seminars will be held at either 09:00 CET or 15:00 CET, depending on the speakers’ locations, to facilitate participation across different regions. Each seminar will last about one hour.

Bringing it all together: using models to build process understanding
Dr. Gregory De Souza (ETH Zurich, Switzerland) – Senior Scientist

Abstract: Two decades of GEOTRACES observations provide us with a wealth of TEI data at a range of spatial scales. Inferring controlling processes from these data requires an understanding of how sources and sinks — whether in the open ocean or at its margins — interact with ocean circulation to produce observed distributions of dissolved species. In this talk, I will give an overview of the diversity of approaches that have used conceptual and/or numerical models to synthesize observational data into an understanding of TEI cycling in the sea and at its interfaces.

Mapping ocean trace metal distributions: A global data-driven view of lead and its isotopes
Dr. Arianna Olivelli (Flanders Marine Institute, Belgium) – Early Career Scientist

Abstract: Despite the rapid growth of GEOTRACES observations, resolving large-scale distributions of trace metals remains challenging due to their sparse and heterogeneous coverage. In recent years, machine learning (ML) techniques have offered new opportunities to advance data-driven oceanographic research at global and regional scales. In this talk, I will present my work to develop the first global maps of lead (Pb) concentrations and isotope compositions from surface to depth using the tree-ensemble algorithm XGBoost and explainable ML tools. These maps provide an observation-based view of Pb distributions and variability that is difficult to achieve from measurements alone. I will discuss key methodological choices, lessons learned, and potential future applications of these maps. Additionally, I will explore the use of different ML approaches for the synthesis and integration of in situ observations within the wider GEOTRACES context.