Modeled and observed fast flow in the Greenland ice sheet
Satellite surface velocity measurements covering 86 % of the Greenland Ice Sheet were used to evaluate a prognostic ice dynamics model on a 3 km grid. A small, but system-atic, exploration of the parameter space considered changes in just three critical model parameters, describing ice soft-ness, no...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.511.1634 http://www2.gi.alaska.edu/snowice/glaciers/iceflow/BKAJS_submit2_twocolumn.pdf |
| Summary: | Satellite surface velocity measurements covering 86 % of the Greenland Ice Sheet were used to evaluate a prognostic ice dynamics model on a 3 km grid. A small, but system-atic, exploration of the parameter space considered changes in just three critical model parameters, describing ice soft-ness, nonlinear basal rheology, and basal water pressure, re-spectively. Parameter combinations were evaluated by com-paring the modeled and observed surface speeds. Best fit to the observed distribution of fast flow occurred with no en-hancement of ice softness, nearly-plastic basal material, and high basal water pressure under fast-flowing ice. The use of a standard amount of ice flow enhancement was seen to generate a distribution of fast flow which is fundamentally different from that in the observed flow, while a specific pa-rameterization of basal sliding generated a close-to-observed distribution. 1. |
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