[Fully-funded studentship covering fees, maintenance stipend (£20,780 p.a. for 2025/26), and research training and support grant (RTSG). International applicants may have the difference between 'home' and 'international' fees waived, but relocation, visa, and health surcharge costs are not covered.] This PhD studentship at the University of East Anglia investigates the impacts of climate change on the Antarctic coastal ocean carbon sink, focusing on the Southern Ocean, which absorbs about 10% of anthropogenic CO2 emissions. The project aims to extend the Rothera carbonate chemistry timeseries through a period of rapid sea ice decline, explore the effects of changing sea ice extent on ocean CO2 uptake, and assess climate change impacts on CO2 uptake at Rothera and along the Antarctic Peninsula. You will be trained in carbonate chemistry analysis and will use a 1-dimensional ocean-ice model to study the effects of variable sea ice and a shift to a long-term low sea ice regime. The research involves analyzing data from Rothera, SOCAT, and mapped CO2 products, as well as determining the drivers of observed changes using oceanographic data, model experiments, satellite, and reanalysis products. The project offers training in chemical analysis, data processing, visualization, and interpretation using coding languages such as Python or Matlab, and provides opportunities to collaborate with the Rothera and POLOMINTS science teams, the British Antarctic Survey, and the National Oceanography Centre. You will present your findings at international conferences and in peer-reviewed publications. While fieldwork is not a core part of the project, there may be opportunities for it. The studentship is fully funded for eligible UKRI candidates, covering tuition fees, a maintenance stipend (£20,780 p.a. for 2025/26), and a research training and support grant. A limited number of studentships are available for international applicants, with the difference between 'home' and 'international' fees waived, though relocation and visa costs are not covered. Applicants should have a strong background in natural sciences, environmental sciences, physics, chemistry, mathematics, or a similar numerical subject, and meet the English language requirements (IELTS 6.5 overall, 6 in each category). The position starts on 1 October 2026, and the application deadline is 7 January 2025.