The objective of the meso-scale modelling is to extend the modelling framework developed in Gagliardini et al. (2007) to overcome three main assumptions made to heuristically derive this law. For this modelling at the meso-scale, the domain represents few meters of ice flowing over a rigid bedrock and the roughness of the bedrock is described by the geometry of the modelled domain itself. The contact between the ice and the bedrock is solved, and the ice bottom surface can detach from the bed to form water filled cavities depending on the imposed basal water pressure. In this approach, periodic boundary conditions are imposed on the side of the modelled domain. Then, for a given imposed water pressure, the meso-scale quantities are obtained by integrating the corresponding quantities over the bedrock.

All the meso-scale modelling will be performed using Elmer/Ice and will consist in the three main improvements:
– 1. Accounting for short-term variation of water pressure in cavities
– 2. Accounting for realistic bump geometry
– 3. Accounting for solid friction at the interface ice-rock