Finite element methods for sea ice modeling

• Main Author: Lietaer, Olivier
• Other Authors: UCL - SST/IMMC/MEMA - Applied mechanics and mathematics, Legat, Vincent, Fichefet, Thierry, Pardoen, Thomas, Goosse, Hugues, Morales Maqueda, Miguel Angel, Weiss, Jérôme
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2011
• Subjects: Finite element method; Sea ice modeling; Lagrangian; Sea ice age; Canadian Arctic Archipelago; Arctic Archipelago; Arctic; Sea ice
• Online Access: http://hdl.handle.net/2078.1/94328

In order to study and understand the behavior of sea ice, numerical sea ice models have been developed since the early seventies and have traditionally been based on structured grids and finite difference schemes. This doctoral research is part of the Second-generation Louvain-la-Neuve Ice-ocean Model (SLIM) project whose objective is to bring to oceanography modern numerical techniques. The motivation for this thesis is therefore to investigate the potential of finite element methods and unstructured meshes for sea ice modeling. The Canadian Arctic Archipelago (CAA) is a complex area formed by numerous islands and coastlines and constitutes a nice application for unstructured meshes. Our model is the first to investigate the effects of resolving the CAA on the ice cover features and the importance of the CAA in terms of mass balance is highlighted. We further develop a Lagrangian and adaptive version of the model allowing the computational grid to move with the ice. We take advantage of the locality of the mesh adaptation procedure to update the discontinuous fields thanks to a local Galerkin projection. Sea ice age patterns and how they change in time provide an integrated view of the recent evolution of sea ice growth, melt and circulation. We first study the vertical age profile in sea ice and analyze the age-thickness relationship in a stand-alone thermodynamic sea ice model of the Arctic. We then take advantage of the Lagrangian model to reproduce the algorithm used to compute satellite retrievals of ice age and compare with different ice age definitions. Several characteristics consistent with satellite observations are deduced from our numerical simulations. (FSA 3) -- UCL, 2011