PhD Studentship - Unravelling the Fate of Excess Heat and Anthropogenic Carbon in the Southern Ocean Using Ocean Tracers and Models

The Southern Ocean accounts for ~40% of the global oceanic uptake of anthropogenic carbon (Cant) and >70% of excess heat, owing to its unique circulation, which connects the deep ocean with the atmosphere and serves as the main ventilation pathway for intermediate and bottom waters. Despite its importance, the historical uptake and redistribution of Cant and heat remain poorly constrained in the sparsely sampled Southern Ocean. Understanding the role of the Southern Ocean in mitigating present climate change through the absorption and storage of Cant and excess heat remains therefore an open question. This project aims to investigate: How have Cant and excess heat been absorbed and accumulated since the industrial era? How are these tracers redistributed within and between ocean basins, along which pathways and over what timescales? How do observationally tracer-derived estimates compare with ocean state estimates and climate model simulations? To address these questions, you will reconstruct Cant and ocean heat uptake since the industrial era using Green’s Functions applied to full-depth hydrographic observations. Combining transient and biogeochemical tracers with surface forcing histories, you will quantify ventilation pathways and storage of Cant and heat in the Southern Ocean. These will provide benchmarks for evaluating the representation of the evolving role of the Southern Ocean in Cant and heat uptake and redistribution in ECCOv4 and CMIP6/7. On-the-job training encompasses model data handling, statistics, scientific programming, climate diagnostics, communication skills, thematic summer schools, workshops and potentially sea-going experience. Exeter provides expertise, new data in ocean ventilation and transient tracers; Plymouth Marine Laboratory in nutrient cycling; CNRS in inverse modelling; British Antarctic Survey in hydrography, alongside access to JASMIN supercomputing and polar research networks. Together, these partners offer a leading-edge interdisciplinary research environment, enabling you to develop scientific independence through conference presentations, publication leadership and the pursuit of novel research. Funding For eligible students the studentship will cover home tuition fees plus an annual tax-free stipend.