A multicomponent coupled model of glacier hydrology 2. Application to Trapridge Glacier, Yukon, Canada



[1] A new glaciohydraulic model is tailored to Trapridge Glacier, Yukon, Canada, where long-term measurements of subglacial water pressure provide parameter constraints and a platform for model evaluation. Using digital elevation models and meteorological data as input, we investigate hydrology on diurnal and seasonal timescales. Quantitative comparisons of simulated and observed pressure records allow us to select a reference model objectively, from which we gain first insights into the gross spatial characteristics of the drainage system. Equilibrium simulations highlight target areas for water storage and potential sticky spots, both of which have established relevance to glacier dynamics. Seasonal simulations capture the key signatures of spring and autumn transitions and corroborate our understanding of the processes involved. Successfully modeled features of the spring transition include increased hydraulic coupling between the surface and bed with time, temporary augmentation of subglacial storage, and rapid subglacial transitions from a hydraulically unconnected to connected state. Autumn transitions are characterized by deterioration of the basal drainage network, drawdown of subglacial storage reservoirs, and heightened sensitivity to precipitation and surface refreezing. Finally, we draw attention to the important role of groundwater transport in cold glacial environments where permafrost can impede drainage from the ice margin.