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SUMMARY:From sky to sea: modelling the production and movement of meltwate
 r through ice sheets and glaciers - Neil Arnold (Geography/SPRI)
DTSTART:20090528T151500Z
DTEND:20090528T163000Z
UID:TALK18559@talks.cam.ac.uk
DESCRIPTION:This paper reviews the development of models of glacier mass a
 nd energy balance and hydrology currently underway by members of the Scott
  Polar Research Institute\, in collaboration with other research institute
 s\, including the Norsk PolarInstitutt\, Norway\, and GEUS\, Denmark.\nThe
  modelling strategy builds on the pioneering 'Arolla' projects based in th
 e Department of Geography in the 1990s through to the early 2000s. This wo
 rk saw the development of a physically-based\, distributed model that coul
 d track the production of melt (using an energy balance approach)\, the su
 praglacial flow of water\, and its entry and subsequent routing in an evol
 ving subglacial hydrological system. The energy balance model component ha
 s now been successfully applied to model the long-term mass balance of a S
 valbard glacier\, Midre Lovenbreen\, over the previous 30 years. The curre
 nt 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 ho
 pe to expand this model to encompass the whole of Svalbard\, and eventuall
 y\, the Greenland Ice Sheet.\nThe subglacial hydrological component is als
 o now being used to model the flow of water beneath the Greenland Ice Shee
 t. Many studies have shown acceleration of flow of the GrIS\, driven in so
 me 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 und
 erstand 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\, u
 nlike for valley glaciers where the tunnels are relatively stable over a s
 ummer season. Ultimately\, we aim to link the mass/energy balance model to
  the hydrology model in order to better predict the possible response of t
 he ice sheet to climatic change.
LOCATION:Hardy Building Room 101\, Department of Geography\, Downing Site
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