Ice Sheet - ocean interactions: Using satellite data to understand ice dynamic change

Ice Sheet - ocean interactions: Using satellite data to understand ice dynamic change
Lead Supervisor: Anna E. Hogg, University of Leeds (UoL)
Co-Supervisors: Pierre Dutrieux, British Antarctic Survey; He Wang, UoL; Adrian Jenkins Northumbria University

Over the last 25-years, Ice sheets in Greenland and Antarctica have raised the global sea level by 1.8 cm since the 1990's, and are matching the Intergovernmental Panel on Climate Change's worst-case climate warming scenarios. In Greenland, mass loss from the ice sheet is dominated by high rates of surface melt during the summer, with individual extreme years having a major impact on the total sea level contribution. Satellite observations have shown that ice loss from Antarctica is dominated by dynamic imbalance in the low-lying, marine-based sectors of West Antarctica; where glaciers in the Amundsen Sea Sector have thinned, accelerated, and grounding-lines have retreated since the 1940's. Ice speedup in West Antarctica is driven by incursions of warm modified Circum-polar Deep Water (mCDW) melting the floating ice, with the interannual and long-term variability of ocean temperatures linked to atmospheric forcing associated with the El Nino-Southern Oscillation (ENSO). The ice sheet contribution to the global sea level budget remains the greatest uncertainty in future projections of sea level rise, driven in part by positive feedbacks such as the Marine Ice Sheet Instability (MISI), and with the most extreme scenarios only possible through the onset of Marine Ice Cliff Instability (MICI). Both long term and emerging new dynamic signals must be accurately measured in order to better understand how ice sheets will change in the future.
Project summary:
This 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 Earth observation experts to better understand change on the Antarctic Ice Sheet, and oceanographers who measure how the ocean impacts on ice melt. Satellite Earth Observation has revolutionized our understanding of the remote and inaccessible Polar Regions. Without this critical resource we would have a far less complete understanding of which regions are changing, the timing and pace at which events occur, and what physical mechanisms are responsible for driving change. During the last 30-years, individual ice streams in Antarctica such as Pine Island Glacier, have increased in speed by over 42% since the early 1990's, and are now known to be dynamically imbalanced. However, despite a clear long-term trend for increasing ice velocity in many regions, the observed speed up has not been constant through time, and multiple years with no significant change have also been observed. 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 and Greenland Ice sheets, 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 Dutrieux at the British Antarctic Survey (BAS) your satellite observations will be combined with observations of ocean temperature, collected using seal tags, moorings, and Automatic Underwater Vehicles, in order to better understand the physical mechanisms driving this change. Through co-supervision by Dr Wang at University of Leeds, you will pioneer the use of advanced computer techniques, such as Artifici