Smoothed particle hydrodynamics non-Newtonian model for ice-sheet and ice-shelf dynamics

We propose a new three-dimensional smoothed particle hydrodynamics (SPH) non-Newtonian model to study coupled ice-sheet and ice-shelf dynamics. Most existing ice-sheet numerical models use grid-based Eulerian discretizations, and are usually restricted to shallow ice-sheet and ice-shelf approximations of the momentum- conservation equation. SPH, a fully Lagrangian particle method, solves the full momentum-conservation equation. Numerical accuracy of the proposed SPH model is first verified by simulating Poiseuille flow, a plane shear flow with a free surface and the propagation of a blob of ice along a horizontal surface. Next, the SPH model is used to investigate the grounding-line dynamics of a ice sheet/shelf. The steady position of the grounding line, obtained from our SPH simulations, is in good agreement with laboratory observations for a wide range of bedrock slopes, ice-to-fluid density ratios, and flux. We examine the effect of non-Newtonian behavior of ice on the grounding-line dynamics. The non-Newtonian constitutive model is based on Glen's law for a creeping flow of a polycrystalline ice. Finally, we investigate the effect of a bedrock geometry on a steady-state position of the grounding line.