We are concerned with enhancing the mechanical parametrizations of the rheological framework employed in the continuum sea ice model developed within SASIP.

The aim is to develop physically sound parametrizations that can translate the dependence of the mechanical strength of the ice cover at the large scale (10-100 km) on both its granular concentration and level of fracturing at the small scale (< 10 km), thereby enabling the rheological framework to represent adequately the spatial and temporal mechanical transition between a dense, brittle ice pack and a loose, granular aggregate of ice floes reminiscent of the Marginal Ice Zone. The methodology will be based on the use of a state-of-the-art discrete element model that can simulate ice floes of realistic shapes and size distributions as well as their mechanical interactions and resulting fracturing. The work package is divided into four parts that will help determining the key variables/parameters to describe the mechanical state of the ice as well as the physical links between these variables/parameters:

1. Discrete model simulations of the evolution of the floe size distribution (FSD) due to fracturing by collision and wave-ice interactions
2. Derivation of large-scale continuum ice strength parametrizations as a function of the small-scale level of fracturing, granular concentration and FSD evolution
3. Implementation and validation of the new parametrizations in the Eulerian version of the sea ice model neXtSIM developed in WP1
4. Simulations of fast transitions between dense and loose sea ice regimes

Permanent people involved in WP2:

• Véronique Dansereau (veronique.dansereau(at)univ-grenoble-alpes.fr)
• Jérôme Weiss (jerome.weiss(at)univ-grenoble-alpes.fr)
• Stéphane Labbé (stephane.labbe(at)sorbonne-universite.fr)
• Christopher Horvat (christopher_horvat(at)brown.edu)
• Pierre Rampal (pierre.rampal(at)univ-grenoble-alpes.fr)
• Laurent Brodeau (laurent.brodeau(at)univ-grenoble-alpes.fr)
• Einar Ólason (einar.olason(at)nersc.no)
• Timothy Williams (timothy.williams(at)nersc.no)
• Martin Vancoppenolle (martin.vancoppenolle(at)locean.ipsl.fr)

Students, Postdocs and enginneers involved in WP2:

• Aurélien Rigotti, Ph.D. student at ISTerre (aurelien.rigotti(at)univ-grenoble-alpes.fr)
• Toai Phan, Ph.D. student at Sorbonne Université (toai.phan(at)upmc.fr)
• Jean-Pierre Auclair, Postdoc at ISTerre (jean-pierre.auclair(at)univ-grenoble-alpes.fr)
• Sophie Thery, engineer at Sorbonne Université (sophie.thery(at)upmc.fr)