Articles | Volume 9, issue 2
The Cryosphere, 9, 675–690, 2015
The Cryosphere, 9, 675–690, 2015

Research article 13 Apr 2015

Research article | 13 Apr 2015

Thermal structure and basal sliding parametrisation at Pine Island Glacier – a 3-D full-Stokes model study

N. Wilkens2,1, J. Behrens3, T. Kleiner2, D. Rippin4, M. Rückamp2, and A. Humbert2,5 N. Wilkens et al.
  • 1Institute for Geophysics, University of Hamburg, Germany
  • 2Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
  • 3Numerical Methods in Geosciences, University of Hamburg, Germany
  • 4Environment Department, University of York, Heslington, UK
  • 5Department of Geosciences, University of Bremen, Germany

Abstract. Pine Island Glacier is one of the fastest changing glaciers of the Antarctic Ice Sheet and therefore of scientific interest. The glacier holds enough ice to raise the global sea level significantly (~ 0.5 m) when fully melted. The question addressed by numerous modelling studies of the glacier focuses on whether the observed changes are a start of an uncontrolled and accelerating retreat. The movement of the glacier is, in the fast-flowing areas, dominated by basal motion. In modelling studies the parametrisation of the basal motion is therefore crucial. Inversion methods are commonly applied to reproduce the complex surface flow structure of Pine Island Glacier by using information of the observed surface velocity field to constrain, among other things, basal sliding. We introduce two different approaches of combining a physical parameter, the basal roughness, with basal sliding parametrisations. This way basal sliding is again connected closer to its original formulation. We show that the basal roughness is an important and helpful parameter to consider and that many features of the flow structure can be reproduced with these approaches.