Discretization of sea ice dynamics in the tangent plane to the sphere by a CD-grid-type finite element

We present a new discretization of sea ice dynamics on the sphere. The approach describes sea ice motion in tangent planes to the sphere. On each triangle of the mesh, the ice dynamics are discretized in a local coordinate system using a CD-grid-like non-conforming finite element method. The development allows a straightforward coupling to the C-grid like ocean model in Icosahedral Non-hydrostatic-Ocean model, which uses the same infrastructure as the sea ice module. Using a series of test examples, we demonstrate that the non-conforming finite element discretization provides a stable realization of large-scale sea ice dynamics on the sphere. A comparison with observation shows that we can simulate typical drift patterns with the new numerical realization of the sea ice dynamics. © 2022 The Authors. Journal of Advances in Modeling Earth Systems published by Wiley Periodicals LLC on behalf of American Geophysical Union