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Projects

Southern Ocean Ice Interactions: Using satellite data to understand ice dynamic change in Antarctica

The Antarctic Ice Sheet contains enough water to raise global sea-levels by 58 m, and as the largest source of potential sea-level rise (SLR) (Church et al., 2013) even modest losses will increase coastal flooding around the world (Vitousek et al., 2017) and affect oceans through freshwater input (Golledge et al., 2019). Since the systematic monitoring of ice sheets began in the early 1990’s, observations have shown the Antarctic Ice Sheet has thinned by up to 9 meters per year, outlet glaciers have sped up by over 40%, 200 km long icebergs have calved, and ice shelves have collapsed catastrophically. Overall, between 1992 and 2017 the Antarctic Ice Sheet has pushed global sea levels up by 7.2 millimetres (Shepherd et al., 2020), and today, mass loss is tracking the upper range of AR5 sea-level predictions (Slater et al., 2020). In Antarctica, ice mass loss is almost entirely (98.9%) driven by ice dynamics (changes in ice flow, calving of icebergs, and melting at the ice-ocean interface), in comparison to the Greenland Ice Sheet where extreme surface melt events dominate the ice loss signal (Slater et al., 2020). Ice dynamics are driven by oceanographic rather than atmospheric processes, making it critically important that the links between Antarctic ice and the South polar ocean are studied. High interannual variability in the observed mass change for the Antarctic dynamic component (0.46 ± 0.16 mm/yr) is not currently reproduced in IPCC AR5 and may not represent the longer-term mass imbalance (Slater et al., 2020). If the current rates of ice loss continue, ice sheets are expected to raise sea levels by a further 17 cm by the end of the century, exposing an additional 16 million people to annual coastal flooding.

Despite the critical role that the ice sheet and ice shelves play in the Antarctic glaciological system, and the known impact of the south Polar ocean on this sensitive Earth system, there are still significant gaps in our knowledge of how these complex processes interlink. By making best use of Earth observation datasets, technological advances of ocean instruments, advanced computer techniques, and progress in ocean and ice sheet modelling; this project provides an exciting opportunity to improve our understanding of the processes driving Southern Ocean and ice interactions.

Project summary:

This PhD project offers an exciting opportunity to work at the interface of climate and space science, making an important contribution to international efforts to study the effects and impact of climate change. In this PhD, you will work closely with world-leading experts in satellite observations, Polar oceanography, and advanced computer techniques, to better understand the ice dynamics of the Antarctic Ice Sheet. Through supervision by Dr Hogg, you will use satellite observations to measure ice speed and then the mass balance of the Antarctic Ice sheet, quantifying the ice sheet sea level contribution over the last 30-years. Synthetic Aperture Radar (SAR) data, from Earth observation satellites including ERS-1/2, TerraSAR-X and Sentinel-1, will be used to track changes in ice speed In Antarctica, using intensity feature tracking and interferometry. Through co-supervision by Dr Meijers at the British Antarctic Survey (BAS) your satellite observations will be combined with ocean models and observations of ocean temperature in order to better understand the physical mechanisms driving this change. Through co-supervision by Dr Tsamados at UCL, you will make use of satellite observations of sea ice extent and thickness to better understand the role that it has in modulating the flow of ice.

What will the student do?

During your PhD you will lead at least three journal papers on these important science topics. The PhD will be based in the School of Earth and Environment at the University of Leeds, and you will therefore have valuable opportunities to work closely with co-supervisors at BAS, and European collaborators through the projects affiliation with the ESA SO-ICE research project that is already funded as part of the ESA Polar cluster. The successful applicant will have access to a broad spectrum of specialist training in Earth Observation and glaciology, in addition to the extensive University of Leeds workshops on a range of topics, including scientific programming through to managing your degree. You may have the option to undertake a Polar field campaign during this PhD. Applicants will hold good first degree (first or high 2.1) or Masters degree in physics, maths, Earth science, climate science, computer science, Earth observation or a related discipline. Expertise in computer programming, while not required, will be a valuable asset. We welcome applications from a wide range of backgrounds, including those with non-traditional qualifications or from industry – please contact us to have a chat about your suitability for the programme.