High-resolution Treatment of Topography and Grounding Line Dynamics in BISICLES

Uncertainties in topography and grounding line locations fundamentally affect modeling of marine ice sheet dynamics, and typically require extremely high resolution models. The dynamic adaptivity of the BISICLES ice sheet model addresses this by adding fine mesh only near where grounding lines are detected, but represents them with a high-resolution stair-step approach. In addition, it is unclear if upstream lower-resolution parts of the domain are sensitive to sub-glacial topography, and how this affects the overall model. We introduce higher-order representations of topography and grounding lines, and assess the sensitivity of ice sheet flow to potentially under-resolved topographical features. We demonstrate that the new solver runs on a variety of hardware platforms, and enables fast, long-term simulations to support analysis needed for understanding sea level rise.