ABSTRACT: Coupling glacial hydrology into a high-order numerical ice model.

CGRG Bibliography of Canadian Geomorphology
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Abstract

A two-dimensional thermomechanical flow-band model is presented that comprises components solving the momentum equations, the advective-diffusive heat equation, and the evolution of the free surface. Longitudinal stretching and lateral shearing play an essential role in the dynamics of large outlet glaciers, especially near the margins and when basal sliding is considerable. Therefore, this model properly accounts for these high-order stress gradients. Model performance is compared with benchmark solutions using model intercomparison exercises and analytical solutions under simplifying assumptions. The model is applied to the Belcher Glacier on the Devon Island ice cap in the Canadian Arctic. Sharing similarities with many Greenland outlet glaciers, this is a large, fast-flowing, tidewater glacier. As such, various basal sliding laws and iceberg calving parameterizations have been incorporated and examined within the model. Surface meltwater, through supraglacial/englacial drainage networks, has an important contribution in the dynamics of polar tidewater glaciers. We therefore incorporate key glaciohydraulic processes into the ice-flow model. These include drainage of supraglacially-stored water through englacial fractures. Under permissible stress and water influx conditions, meltwater can drain to the bed, providing lubrication to the sole of the glacier. We demonstrate how this process affects model behavior under geometry and meltwater conditions appropriate for polar glaciers.

Bibliography of Canadian Geomorphology