Student Seminar: Mathieu Plante

Modeling Land-fast Ice Using a Linear Elastic Rheology

Land-fast ice is an important component of the Arctic system, capping the coastal Arctic waters for most of the year and exerting a large influence on ocean-atmosphere heat exchanges. Yet, the accurate representation of land-fast ice in most large-scale sea ice models remains a challenge, part due to the difficult (and sometimes non-physical) parametrisation of ice fracture. In this study, a linear elastic model is developed to investigate the internal stresses induced by the wind on the land-fast ice, modelled as a 2D elastic plate. The model simulate ice fracture by the implementation of a damage coefficient which causes a local reduction in internal stress. This results in a cascade propagation of damage, simulating the fracture of a land-fast ice cover. 
To estimate the large scale mechanical properties of land-fast ice, land-fast ice break up events and ice bridge formations are observed in the Siberian Arctic. These events are identified using brightness temperature imagery from the MODIS (Moderate Resolution Imaging Spectroradiometer) Terra and Aqua satellites, from which the position of the flaw lead is identifiable by the opening of polynyi adjacent to the land-fast ice. The shape of the land-fast ice before, during and after these events, along with the characteristic scale of the resulting ice floes, are compared to the model results to extrapolate the stress states that corresponds to these observations. These results will then be used to determine the model setting that best reproduce the scale of the observed break up events.