Articles | Volume 10, issue 3
The Cryosphere, 10, 1339–1359, 2016
The Cryosphere, 10, 1339–1359, 2016

Research article 01 Jul 2016

Research article | 01 Jul 2016

A Maxwell elasto-brittle rheology for sea ice modelling

Véronique Dansereau1, Jérôme Weiss2, Pierre Saramito3, and Philippe Lattes4 Véronique Dansereau et al.
  • 1Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS UMR 5183, Université de Grenoble, Grenoble, France
  • 2Institut des Sciences de la Terre, CNRS UMR 5275, Université de Grenoble, Grenoble, France
  • 3Laboratoire Jean Kuntzmann, CNRS UMR 5224, Université de Grenoble, Grenoble, France
  • 4TOTAL S.A. – DGEP/DEV/TEC/GEO, Paris, France

Abstract. A new rheological model is developed that builds on an elasto-brittle (EB) framework used for sea ice and rock mechanics, with the intent of representing both the small elastic deformations associated with fracturing processes and the larger deformations occurring along the faults/leads once the material is highly damaged and fragmented. A viscous-like relaxation term is added to the linear-elastic constitutive law together with an effective viscosity that evolves according to the local level of damage of the material, like its elastic modulus. The coupling between the level of damage and both mechanical parameters is such that within an undamaged ice cover the viscosity is infinitely large and deformations are strictly elastic, while along highly damaged zones the elastic modulus vanishes and most of the stress is dissipated through permanent deformations. A healing mechanism is also introduced, counterbalancing the effects of damaging over large timescales. In this new model, named Maxwell-EB after the Maxwell rheology, the irreversible and reversible deformations are solved for simultaneously; hence drift velocities are defined naturally. First idealized simulations without advection show that the model reproduces the main characteristics of sea ice mechanics and deformation: strain localization, anisotropy, intermittency and associated scaling laws.

Short summary
In this paper we present a new mechanical modelling framework for the deformation of sea ice on regional and larger scales named Maxwell elasto-brittle. The model successfully reproduces the formation of narrow, oriented leads which concentrate the deformation within the damaged, i.e., fractured, ice as well as the intermittency of the damaging process, and hence represents a relevant contribution to the ongoing development of operational modelling platforms, regional and global climate models.