GROUNDING LINE PROCESSES AND ICE SHEET MODELS (Invited Presentation)

Grounding lines are key controls on marine terminating glaciers as they control both the dynamics of ice streams and the overall mass balance of glaciers. Accurate representation of grounding line retreat in numerical models is very important for modeling ice sheet evolution. The marine instability, condition where a marine ice sheet grounding line is unstable due to being grounded under seal level and over retrograde slope, is a critical mechanism that could lead to large and rapid retreat of ice sheets over the next centuries. Many internal and external parameters impact grounding line evolution, from ocean conditions under floating ice shelves to ice sheet geometry.

In this presentation, we review the processes impacting grounding line evolution as well as the recent progress made in understanding grounding line evolution and its representation in ice sheet models. We show examples of modeling studies from a variety of applications, from idealized cases to real glaciers and compare them with remote-sensing observations of glaciers.

This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration, Cryospheric Sciences and Sea Level Rise Programs.