Upcoming
Friday 16:00 @ Nordita 6th floor
Scandinavian peoples have been skiing for thousands of years; today more than 50 million people worldwide enjoy recreational skiing. Skiing, combining high speeds with snow’s unique properties, offers an excellent venue to demonstrate physical principles. In this talk we’ll discuss the physics that underlies every aspect of the sport, from the dynamics of turns and the material properties of composite skis, to the terrifying power of avalanches.
Accurate projections of mass loss from the Antarctic Ice Sheet depend on precise modelling of ice flow. Ice flow is routinely modelled as a non-Newtonian fluid using a power law called Glen’s flow law, but this approach neglects the inherent direction-dependent viscosity of ice. This simplification leads to a discretised ice-sheet model that is both computationally efficient and numerically stable, capable of modelling entire ice sheets. However, model intercomparison projects have revealed large discrepancies between ice-sheet models and uncertainty in future sea level projections. In this talk, I will present an overview of model developments in the area of anisotropic ice-flow modelling, an alternative to Glen’s flow law that accounts for the evolution of the crystal orientation of ice, offering a more accurate representation of ice dynamics. I will present 3D simulations of coastal regions of Antarctica, comparing modelled crystal orientation with observations of ice crystal structure obtained from quad-polarimetric radar data.