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| Titel |
Mass-conserving subglacial hydrology in the Parallel Ice Sheet Model version 0.6 |
| VerfasserIn |
E. Bueler, W. Pelt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1991-959X
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| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 8, no. 6 ; Nr. 8, no. 6 (2015-06-02), S.1613-1635 |
| Datensatznummer |
250116399
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| Publikation (Nr.) |
 copernicus.org/gmd-8-1613-2015.pdf |
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| Zusammenfassung |
| We describe and test a two-horizontal-dimension subglacial hydrology model
which combines till with a distributed system of water-filled, linked
cavities which open through sliding and close through ice creep. The addition
of this sub-model to the Parallel Ice Sheet Model (PISM) accomplishes three specific
goals: (a) conservation of the mass of water, (b) simulation of spatially
and temporally variable basal shear stress from physical mechanisms based on
a minimal number of free parameters, and (c) convergence under grid
refinement. The model is a common generalization of four others: (i) the
undrained plastic bed model of Tulaczyk et al. (2000b), (ii) a standard
"routing" model used for identifying locations of subglacial lakes, (iii)
the lumped englacial–subglacial model of Bartholomaus et al. (2011), and
(iv) the elliptic-pressure-equation model of Schoof et al. (2012). We
preserve physical bounds on the pressure. In steady state a functional
relationship between water amount and pressure emerges. We construct an exact
solution of the coupled, steady equations and use it for verification of our
explicit time stepping, parallel numerical implementation. We demonstrate the
model at scale by 5 year simulations of the entire Greenland ice sheet at
2 km horizontal resolution, with one million nodes in the hydrology grid. |
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