The Physics of Ice Sheets - Rapidly Changing Complex Systems

The ice sheets in Greenland and Antarctica are loosing mass at an unprecedented rate during the observational period, underlining the urgent need for a better understanding of the physics of ice sheets. In contrast to nuclear and elementary particle physics, glaciology is very limited in conducting laboratory experiments - nature is doing a large experiment and glaciologists conduct observations using in-situ, airborne and spaceborne instruments. While ice sheets are basically gravity-driven lubricated flow, they are complex system due to non-linear interactions of processes on various spatial scales making it a multiphysics problem. Continuum mechanical models are used to describe the dynamics of glaciers, ranging from the large-scale fluid mechanical problem, to fracture mechanics and hydrological models for meltwater dynamics. While large scale numerical ice sheet models became more advanced in the past decade, the challenge is the incorporation of processes and the adequate representation of their interaction - glaciologist's known unknowns.

Here we will discuss the recent changes of the ice sheet systems, as well as the recent advances of glacier modelling and gaps to overcome in the future.