On the development of a hybrid sea-ice model by combining particle and continuums mechanics

Currently climate models represent sea ice by a continuums approach. The continuums assumption implies that statistical averages can be taken over a large number of floes.  But the application of continuum rheological models at or below the scale of individual floes is only appropriate if the mode of failure of a single floe is the same as the mode of failure of an aggregate of floes. Continuum models have been developed for a grid resolution of 100 km. In last years computing power has increased and sea-ice models are often run at high mesh resolutions where a grid cell may no longer contain a representative sample of sea-ice floes.

We are addressing these shortcomings of current continuum sea-ice models by developing a hybrid model. The idea of the hybrid approach is to nest a Discrete Element Model into a continuum sea-ice model in order to predict sea ice on fine spatial scales in a region of interest. To facilitate the coupling between the continuum and Discrete Element Model a Particle-in-Cell scheme is used which ensures mass conservation in the hybrid approach. We analyze the coupling of the continuums and particle mechanics and discuss the advantages and disadvantages of this approach.