57A132
Applications of the Finite Element Louvain-la-Neuve Sea-Ice
Model (FELIM): on the sphere, in the Canadian Arctic Archipelago and with a
moving grid
Sylvain Bouillon, Olivier Lietaer, Thierry Fichefet, Vincent
Legat
Corresponding author: Sylvain Bouillon –
sylvain.bouillon@uclouvain.be
The FELIM model is being developed in the scope of the
Second generation Louvain-la-Neuve Ice-ocean Model (SLIM). This sea-ice model
has representations of both dynamic and thermodynamic sea-ice processes and
includes viscous–plastic rheology along with a complete parameterization
of the atmospheric fluxes. The dynamical equations are written in a local
element-based coordinate system solving the problem of the singularity at the
poles arising when the mesh is based on a geographical coordinate system. The
numerical resolution of this set of equations involves the standard Galerkin
formulation and a Newton iterative procedure. The climatological sea-ice drifts,
thicknesses and concentrations computed by the model compare qualitatively well
with the observations. Unstructured meshes, with their natural ability to fit
boundaries and increase locally the mesh resolution, propose an alternative
framework to capture the complex oceanic areas formed by coasts and islands such
as the Canadian Arctic Archipelago (CAA). We have shown that the local and
short-term influences of the ice exchanges through the CAA are non-negligible.
In particular, whether some straits are open or closed in the numerical
experiment influences directly the numerical solution in the vicinity of those
straits. Moreover, on average, the sea-ice volume in the CAA represents 10% of
the total sea-ice volume in our model and a non-negligible freshwater volume is
exported to Baffin Bay and the Labrador Sea. Another ongoing study is the
development of a Lagrangian adaptive sea-ice model allowing the computational
grid to move with the ice drift. In order to maintain a good quality of the
mesh, the mesh has to be adapted during the simulation, involving particular
mesh adaptation techniques. This Lagrangian version of the model has several
interesting applications, such as the dynamical mesh refinement along any region
of interest (e.g. the ice edge), buoys tracking, or the inclusion of material
properties in the rheology.
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