As part of the NERC-funded INSPIRE Doctoral Training Partnership (https://www.inspire-dtp.ac.uk/), we are seeking applicants for a competition-funded PhD studentship entitled “The changing freshwater composition of the South Atlantic and Southern Ocean: causes and impacts”. This is a joint project between the British Antarctic Survey (in Cambridge) and the University of Southampton, with supervisors Povl Abrahamsen (BAS), Alberto Naveira Garabato (UoS), Mike Meredith (BAS), Robert Mulvaney (BAS), and Alex Brearley (BAS). The brief project description is:
The Southern Ocean exerts a disproportionate influence on our planet’s climate, via the strong drawdown of anthropogenic carbon and heat from the atmosphere that occurs there. This role is intimately connected to the Southern Ocean circulation; it is the key region globally where old waters are upwelled to the surface, and new waters created that sink back into the ocean interior. Freshwater inputs to the ocean can impact this circulation, by affecting density gradients and the stability of the upper ocean. Both sea ice meltwater and the melt of Antarctic glaciers exert such an influence, and both are known to be strongly variable, both in time and space. This project will use a tracer of freshwater inputs – the stable isotopes of oxygen in seawater – from the South Atlantic sector of the Southern Ocean to distinguish sea ice melt from other sources of freshwater in historical and recent ocean datasets. By linking these measurements with conventional oceanographic data, satellite data and the outputs of computer simulations, the student will determine the impact of known freshwater inputs on oceanographic circulation, the level to which variability in these sources impacts the ocean, and how such changes might influence climatically-important processes into the future.
When measured alongside salinity, the ratio of stable isotopes of oxygen in seawater is a key tracer for quantifying the input of sea ice melt separately from freshwater from other sources (glacial melt, precipitation). Substantial datasets of oxygen isotopes now exist, with many obtained recently from the NERC-funded ORCHESTRA programme (Ocean Regulation of Climate via Heat and Carbon Sequestration and Transport; https://www.orchestra.ac.uk). Ocean freshwater composition will be derived from these datasets using mass balance techniques, along with quantitative estimates of ocean circulation from inverse techniques applied to conventional oceanographic data, building on, and complementing, the inverse modelling that is being performed as part of ORCHESTRA. This will enable the ocean transports of different freshwater types to be determined, and their changes over time to be quantified. The availability of new datasets will enable these analyses to take place over larger spatial scales (i.e. basin scale) than has been done before. Relating these results to remotely-sensed quantifications of sea ice change and glacial ice change on Antarctica will reveal the impact on the ocean of the different freshwater inputs.
You can find more information about the project at https://www.findaphd.com/phds/project/the-changing-freshwater-composition-of-the-south-atlantic-and-southern-ocean-causes-and-impacts/?p123752. Links to eligibility criteria and how to apply can be found at https://www.inspire-dtp.ac.uk/how-apply. The deadline for applications is 4 Jan 2021, with interviews in the second half of February, and project start in late September 2021.
If this project doesn’t float your boat, other ocean/environment/climate-related projects from the INSPIRE Doctoral Training Partnership can be found at https://noc.ac.uk/gsnocs/projects/inspire
Please note that international students are eligible to apply; a limited number of studentships can be made available to international students. However, as things currently stand, the funding for these studentships will not cover the difference between UK and overseas tuition fees, leaving a shortfall of roughly £20k per year over the course of the 3.5-year PhD (~£70k in total). If you are not a UK citizen or permanent resident, you will need a plan for how you will cover these fees, e.g. through other grant sources. It is also possible that this situation might change before the start of the studentships – I certainly hope so – but this is not confirmed at present.