Background and Rationale
The Arctic holds 3.07 ± 0.02 106 km3 of land-ice, for an equivalent potential sea level rise of 7.6 m. Since the early 2010s, nearly half of the global sea-level rise has been caused by melting of Arctic ice, with glaciers and ice caps accounting for ~35% of global sea-level rise since the early 2010s, while the Greenland Ice Sheet contributed to ~15% of global sea level. Loss of land-ice is currently increasing as atmospheric and oceanic forcing intensify and as Arctic sea ice cover shrinks. Loss of land ice has been a key player in the local freshwater budget and impact thermohaline forcing in the North Atlantic. Furthermore, the dynamic response of land ice to climate forcing constitutes the main uncertainty in global sea level projections for the next century.
Melting is driven primarily by external forcings including atmospheric temperature, ocean temperature and sea-ice concentration variabilities. With global warming, climate predictions show amplified warming near the poles. This warming heats the surface of the oceans and also melts the freshwater stored in ice. When freshwater is released to the ocean, it adds buoyancy to the surface layers of the ocean, thereby reducing its susceptibility to deep water formation under the influence of strong wintertime storms. Freshwater influences have been used to explain paleo-climate shifts through shutting down the large-scale ocean overturning circulation and have been observed to halt deep water convection in observational records.
Aim and Key Research Questions
The aim of the research is to identify connections and processes linking loss of land-ice to processes in the ocean, atmosphere and sea ice across the Arctic region.
The key objectives of the work will be to:
Consolidate a record of pan-arctic time-dependant land-ice change from spaceborne Earth-Observation (i.e. Swath and laser altimetry, SAR, Optical) and compile existing records of ocean, atmosphere and sea-ice trends.
Develop, test and apply novel time-series analysis and complex network method to unearth spatio-temporal teleconnections in Arctic climate system, Northern Atlantic circulation and land ice masses.
Propose a quantitative framework that links atmospheric and oceanic forcings to land-ice loss and sea level change.
Indicative timescale of activities and training
You will be supervised by glaciologists, remote sensing and oceanographic experts at the University of Edinburgh and at the National Oceanographic Center in Southampton. In addition you will interact with the data science company Earthwave based in Edinburgh and with our partner at UCL. The SENSE DTP programme provides comprehensive training in Earth Observation and Data Science, as well as training in personal and professional development alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered and hosted at the University of Edinburgh for 3.75 years with an industry placement for 0.25 year.
Required skills and qualifications prior to application
We seek an enthusiastic student with strong numerical/computational grounding. Previous experience in Earth Observation and climate sciences is desirable although ample training and opportunity to develop these skills will be provided during the PhD.
This PhD is part of the NERC and UK Space Agency funded Centre for Doctoral Training "SENSE": the Centre for Satellite Data in Environmental Science. SENSE will train 50 PhD students to tackle cross-disciplinary environmental problems by applying the latest data science techniques to satellite data. All our students will receive extensive training on satellite data and AI/Machine Learning, as well as attending a field course on drones, and residential courses hosted by the Satellite Applications Catapult (Harwell), and ESA (Rome). All students will experience extensive training on professional skills, including spending 3 months on an industry placement. See http://www.eo-cdt.org
Gourmelen, N, et al., 2017, ‘CryoSat-2 swath interferometric altimetry for mapping ice elevation and elevation change’, Advances in Space Research. https://doi.org/10.1016/j.asr.2017.11.014;
Dotto, T.S., et al., (2018) Variability of the Ross Gyre, Southern Ocean: Drivers and Responses Revealed by Satellite Altimetry, Geophysical Research Letters, 10.1029/2018GL078607
Frajka-Williams, E., Bamber, J. & Vage, K. (2016) Greenland melt and the Atlantic meridional overturning circulation. Oceanography 29, 22–33