Heather Selley

Heather Selley

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Twitter: @HeatherSelley

Antarctic/Greenland ice sheet mass balance from high resolution 'swath mode' CryoSat-2 altimetry data

Based within the Centre for Polar Observation and Modelling (CPOM), the project is co-funded by the European Space Agency (ESA) linked with the ESA's Support To Science Element (STSE) programme.

Glacier and ice sheet topography are direct measures of glacier mass change and are fundamental parameters of regional models of ice mass trends (Rignot et al., 2003). Repeat-observations of ice sheet topography are crucial to quantifying ice thickness, estimate mass change and potential contribution to sea level change. Therefore, Earth Observation data from satellites such as ESA's CryoSat-2 will be used to assess the Antarctic and Greenland ice sheets contribution to sea level rise (SLR) and how this contribution varies temporally and spatially globally.

The novel 'swath mode' processing technique will be utilised to produce super-high resolution satellite observations of surface elevation change. Traditional pulse-limited altimetry only provides relatively coarse spatial resolution elevation measurements. Higher resolution data is needed as ~50 and ~70% of Antarctic and Greenland ice sheet of quantified mass loss has occurred within 100 km of the coast. From this, less than 30% is surveyed by conventional altimetry due to sparse satellite ground tracks and coarse resolution footprints where data retrieval is poor due to steep slopes. 'Swath mode' uses the phase and slope information of the altimetry range (the distance between the Earth surface and the satellite) to generate 100s of data points perpendicular to the satellite ground track (Grey et al., 2013). This processing method enables the production of data an order of magnitude greater then conventional altimetry (i.e. grids 5 km x 5 km to 0.5 km x 0.5 km).

This project will therefore aims to improve understanding of spatially variable patterns of ice mass loss from the Polar ice sheets and develop case studies illustrating the benefit of the high resolution 'swath mode' dataset.

References:

Rignot, E., Rivera, A., and Casassa, G., 2003, Contribution of the Patagonia Icefields of South America to sea level rise: Science, v. 302, p. 434-437.

Grey, L., D. Burgess, L. Copland, R. Cullen, N. Galin, R. Hawley, V. Helm (2013) Interferometric swath processing of CryoSat-2 data for glacial ice topography, The CryoSphere, 7, 3133-3162, doi: 10.5194/tcd-7-3133-2013.

Research interests

  • Earth Observation of the Cryosphere
  • Glaciology
  • Altimetry
  • Ice Velocity 

Qualifications

  • MSc, Glaciology, Aberystwyth University
  • BSc, Physical Geography, University of Exeter

Research groups and institutes

  • Institute for Climate and Atmospheric Science