Wave-induced structural gradients in Antarctic sea ice cover - ANTGRAD

Antarctic sea ice stretches in winter about 1000 km from the coast, and decreases in summer to one sixth of the winter area. At its boundary, the ice cover meets the Southern Ocean and waves up to 20 m high penetrate the ice. The waves are felt in a 100-300 km wide marginal ice zone, MIZ. In winter the waves prevent the formation of continuous ice, and fields of small floes looking like pancakes form instead. In summer the waves fragment the ice and speed up its decay. Forecasting the conditions in MIZ is an important component in Souther Ocean and global modelling. For this we need to know how the waves affect the ice cover and how they die off when travelling through the ice. The ANTGRAD project studies this theoretically and though observations from ships and by satellites. It also makes experiments in a 40x40 m test basin where ice and waves are generated to mimick MIZ, and studies how the MIZ conditions affect ships travelling trough it. This is relevant also for Arctic shipping.