Modelling glacier mass changes on regional and global scales

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Retreat of mountain glaciers and ice caps worldwide is one of the key indicators of recent climate change. On a global scale, the mass loss from glaciers contributes to sea level rise. On a regional and local scale, glacier melt-water is an important contributor to river flow during dry and warm parts of the year. In western Canada, maintenance of low flows by glacier runoff is essential to sustain aquatic ecosystems and hydropower generation. Furthermore, glaciers of western Canada and the Canadian Arctic substantially contribute to sea level rise and are expected to do so for the next 50-100 years. Current attempts to project glacier mass changes on regional and global scale rely on simplified numerical models where the amount of glacier melt depends only on air temperature. Because of their simplicity, these empirically-based models are widely used to simulate mass change of glaciers and ice sheets, however, they neglect important surface energy terms such as solar radiation and latent heat. A more physically correct approach is to apply an energy mass balance model that tracks all energy terms that affect the surface of a glacier. The overall aim of this study is to improve our attempts at modelling glacier response to climate change by developing an energy mass-balance model on regional scale. Initially, the study area will consist of all the glaciers in western Canada. The glacier model will be forced by high-resolution climate fields from a mesoscale atmospheric model. A monitoring network of several different glacier sites in the domain will be installed in order to generate high-quality energy and mass flux data that can be used to validate the mass-balance model. The proposed research will improve our understanding of processes at the glacier-atmosphere interface by investigating full energy coupling at the glacier surface, and improve modelling of glacier mass changes on regional scales, narrowing the uncertainties in the projections of glacier mass loss.