Geometric remapping of particle distributions in the Discrete Element Model for Sea Ice (DEMSI v0.0)

Abstract. A new sea ice dynamical core, the Discrete Element Model for Sea Ice (DEMSI), is under development use in coupled Earth system models. DEMSI based on discrete element method, which models collections of floes as interacting Lagrangian particles. In basin-scale simulations motion results significant convergence and ridging, requires periodic remapping variables from a deformed particle configuration back to an undeformed initial distribution. At resolution required we cannot resolve individual floes, so adopt sub-grid-scale thickness distribution used continuum This choice leads series hierarchical tracers depending fractional area or concentration that must be remapped consistently. The circular elements employed help improve computational efficiency at cost increased complexity effective definitions cover are accurate enforcement conservation. An additional challenge values along edge, location varies due this paper describe particle-to-particle approach well-established geometric ideas enforces conservation, bounds preservation, compatibility between associated tracer quantities, while also robustly managing edge. One algorithm novel optimization-based flux correction case nonuniform motion. We demonstrate accuracy utility numerical test cases.