Thomas Zwinger
Finnish IT Center for Science, CSC
Helsinki, Finland
The dynamics of ice sheets in contact with ocean waters impose the biggest challenge to ice dynamic models. First of all, the sudden change in the stress field demands the resolution of vastly changing flow behaviour from thin film shear type in the interior of ice sheets to (if existing) membrane stress dominated ice shelf dynamics. We will shortly present the possible ways to account for this switch in continuum ice sheet models.
At the ice front, as well as the fast outlet systems, the two aspects of material properties of ice, namely reacting as a brittle elastic solid on short time scales as well a shear thinning fluid on timescales exceeding hours have an impact on the dynamics. To cover these dualism in mechanical behaviour, we describe the coupling of a recently introduced discrete element method that is capable of simulation short time elastic-brittle reaction of ice fronts and surface crevasses to the well established full stress ice sheet model Elmer/Ice.