From sky to sea: modelling the production and movement of meltwater through ice sheets and glaciers

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• Neil Arnold (Geography/SPRI)
• Thursday 28 May 2009, 16:15-17:30
• Hardy Building Room 101, Department of Geography, Downing Site.

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This paper reviews the development of models of glacier mass and energy balance and hydrology currently underway by members of the Scott Polar Research Institute, in collaboration with other research institutes, including the Norsk PolarInstitutt, Norway, and GEUS , Denmark. The modelling strategy builds on the pioneering ‘Arolla’ projects based in the Department of Geography in the 1990s through to the early 2000s. This work saw the development of a physically-based, distributed model that could track the production of melt (using an energy balance approach), the supraglacial flow of water, and its entry and subsequent routing in an evolving subglacial hydrological system. The energy balance model component has now been successfully applied to model the long-term mass balance of a Svalbard glacier, Midre Lovenbreen, over the previous 30 years. The current generation of this model uses ERA40 reanalysis data to drive the model, and it includes accumulation and a detailed treatment of the subsurface processes, including re-freezing of meltwater within the snow pack. We hope to expand this model to encompass the whole of Svalbard, and eventually, the Greenland Ice Sheet. The subglacial hydrological component is also now being used to model the flow of water beneath the Greenland Ice Sheet. Many studies have shown acceleration of flow of the GrIS, driven in some areas by increased inputs of surface water through the body of the ice sheet. Theory would suggest that this will raise subglacial water pressure, and increase flow velocity, and a model-based approach can help to understand the nature and consequences of these changes in water availability. The large ice thicknesses mean that the behaviour of the model drainage system is quite different to that in small glaciers, however; large ice thicknesses lead to rapid collapse of any tunnel-based drainage system, unlike for valley glaciers where the tunnels are relatively stable over a summer season. Ultimately, we aim to link the mass/energy balance model to the hydrology model in order to better predict the possible response of the ice sheet to climatic change.

This talk is part of the Department of Geography - main Departmental seminar series series.

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• Department of Geography - main Departmental seminar series
• Hardy Building Room 101, Department of Geography, Downing Site

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