As explained above, sea ice is a very important and interactive climate parameter. It has not been modeled responsively to the role it plays, but rather simply as a deforming slab, in most cases. There is, however, a simple and effective way to model sea ice, which was suggested by Zubov in 1943 and is widely used in operational sea ice forecasting. Elastic materials bounce back. If a material is viscous, its density increases but it doesn't come back if the pressure on it is released.
Plastic materials break under sufficient pressure.
Sea ice has been modeled mainly as a slab, and either as an elastic plastic material, a viscous plastic material or an elastic viscous material. Sea ice has not been modeled effectively in GCMs. The earliest attempts to account for sea ice in GCMs involved simply treating it as a swamp - a thick layer that doesn't do anything. The next level of sophistication involves a simple mixed layer or slab ocean and accounts for a layer of sea ice, but one that is deformed with elastic, plastic or viscous properties, which is not a correct representation and does not account for interplay. Even the current best treatments are not realistic and do not properly include the interaction of sea ice with climate.