Basal friction of Fleming Glacier, Antarctica – Part 1: sensitivity of inversion to temperature and bedrock uncertainty

• Published in: The Cryosphere
• Main Authors: Zhao, C, Gladstone, RM, Warner, RC, King, MA, Zwinger, T, Morlighem, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2018
• Subjects: glacier modelling; inversion; Fleming Glacier; Antarctic; Antarctic Peninsula; The Antarctic; Antarc*; Antarctica; Ice Sheet; Ice Shelf
• Online Access: https://eprints.utas.edu.au/28011/; https://eprints.utas.edu.au/28011/1/tc-12-2637-2018.pdf; https://eprints.utas.edu.au/28011/2/127892%20-%20Basal%20friction%20of%20Fleming%20Glacier,%20Antarctica%20Part%201.pdf

Many glaciers in the Antarctic Peninsula are nowrapidly losing mass. Understanding of the dynamics of thesefast-flowing glaciers, and their potential future behaviour,can be improved through ice sheet modelling studies. Inversemethods are commonly used in ice sheet models toinfer the spatial distribution of a basal friction coefficient,which has a large effect on the basal velocity and ice deformation.Here we use the full-Stokes Elmer/Ice model tosimulate theWordie Ice Shelf–Fleming Glacier system in thesouthern Antarctic Peninsula. With an inverse method, weinfer the pattern of the basal friction coefficient from surfacevelocities observed in 2008. We propose a multi-cyclespin-up scheme to reduce the influence of the assumed initialenglacial temperature field on the final inversion. This isparticularly important for glaciers like the Fleming Glacier,which have areas of strongly temperature-dependent deformationalflow in the fast-flowing regions. Sensitivity testsusing various bed elevation datasets, ice front positions andboundary conditions demonstrate the importance of highaccuracyice thickness/bed geometry data and precise locationof the ice front boundary.