Abstract

Arctic sea ice after more than three decades of prolonged thinning and shrinking has transformed radically. With this dramatic evolution comes the necessity to reevaluate the physical processes involving sea ice and, in particular, the driving mechanisms that set the ice in motion and redistribute its mass into and out of the Arctic basin. Sea ice dynamics is dominated by three forces, the atmospheric and oceanic drag and the internal forces in the ice. All are inadequately represented in current general circulation models (GCMs). I present results over the Arctic of a stand-alone version of the sea ice model, CICE , and show the influence of a new anisotropic rheology and a new drag parameterisation on the motion and mass of the ice cover. The impact of this new physics on the Arctic sea ice properties is large and seems to explain some of the differences between models and observations. I will also discuss some recent work where we have tested the impact of our new physics on the sea ice characteristics in the Antarctic