Effects of rheology and ice thickness distribution in a dynamic-thermodynamic sea ice model

Realistic treatment of sea ice processes in general circulation models is n eeded to simulate properly global climate and climate change scenarios. As new sea ice treatments become available, it is necessary to evaluate them i n terms of their accuracy and computational time. Here, several dynamic ice models are compared using both a 2-category and 28-category ice thickness distribution. Simulations are conducted under normal wind forcing, as well as under increased and decreased wind speeds. it is found that the lack of a shear strength parameterization in the cavitating fluid rheology produces significantly-different results in both ice thickness and ice velocity tha n those produced by an elliptical rheology. Furthermore, use of a 28-catego ry ice thickness distribution amplifies differences in the responses of the various models. While the choice of dynamic model is governed by requireme nts of accuracy and implementation, it appears that, in terms of both param eterization of physical properties and computational time, the elliptical r heology is well-suited for inclusion in a GCM.