Sylvain Bouillon's PhD Thesis

Over the last 30 years, the Arctic sea ice has been declining at a rapid pace. This is one of the most striking manifestations of the global warming. These changes greatly affect the Arctic populations and ecosystems, but also the regional and global climate system.
To understand the complex role played by sea ice in the Earth system and to make reliable projections, scientists use coupled atmosphere-ocean-sea ice models, which are validated against satellites and in-situ observations. Sea ice models developed for this purpose correctly reproduce the seasonal cycle of sea ice growth and melt and the mean ice motion, but poorly simulate the ice deformation, especially at small spatial (~10 km) and temporal scales (~3 days). This deficiency is very problematic since small-scale deformation generates leads in the ice cover, allowing large heat fluxes from the ocean to the atmosphere.
During my thesis, I developed innovative approaches to improve sea ice rheologies for large scale models with a special interest for the Arctic region. My work within the state-of-the-art NEMO-LIM model and the next generation finite element SLIM model provided a better understanding of the sea ice dynamics. Thanks to the implementation of a new rheology based on the elasto-brittle framework, we succeeded in better simulating the complex behaviour of the ice pack, which is characterized by strong localisation of the deformation along linear features spanning all the Arctic basin.

Jury:
Prof. V. LEGAT (UCL) (Promotor)
Prof. T. FICHEFET (UCL) (Promotor)
Prof. M.-L. DE KEERSMAECKER (UCL) (President)
Prof. H. GOOSSE (UCL)
Dr. J. WEISS (Université J. Fourier, Grenoble, Fr.)
Dr. M.A. MORALES MAQUEDA (National Oceanography Centre, U.K.)