Sea ice dynamics solvers in the MITgcm
Most dynamic sea ice models for climate type simulations are based on the viscous-plastic (VP) rheology. New rheologies such as the Maxwell-Elasto-Brittle (MEB) rheology are usually compared against traditional VP-schemes, but the new schemes also require revisiting the validity of VP-schemes. So far, comparisons between different schemes are confounded by factors unrelated to rheology, such as grid resolution, advection schemes, forcing by atmosphere and ocean, and last but not least, by differences in numerical details of different model codes. The sea ice component of the Massachusetts Institute of Technology general circulation model (MITgcm) offers an easy-to-use testbed for comparing different sea ice rheologies and implementation that avoids any confounders because all solvers share the same code and configuration environment. VP-rheologies with different flavors of Picard (or fixed point iterative) solvers, Newton methods, and different variants of the Elastic-Viscous-Plastic solver have been evaluated in this framework. With this framework, a new implementations such as an MEB solver may be compared to these traditional solvers in idealized geometries and in realistic Arctic configurations.