 |
| Titel |
Parameterising the grounding line in flow-line ice sheet models |
| VerfasserIn |
R. M. Gladstone, A. J. Payne, S. L. Cornford |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 4, no. 4 ; Nr. 4, no. 4 (2010-12-15), S.605-619 |
| Datensatznummer |
250001908
|
| Publikation (Nr.) |
 copernicus.org/tc-4-605-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Realistic predictions of the behaviour of marine ice sheets require that models are able to robustly
simulate grounding line migration.
Fixed-grid ice sheet models have been shown to exhibit inconsistent
and hence unreliable grounding line migration, except at very high resolution not yet achievable in
whole ice sheet simulations.
In this study we present several different approaches
to parameterising the grounding line.
These are distinguished by choices regarding the ice thickness profile from the last
grounded to the first floating grid point, and how this profile impacts the gravitational driving stress
and basal drag. We demonstrate that the most obvious choice of thickness parameterisation, linear interpolation
from the last grounded to the first floating grid point, is not the most effective.
We show that
use of a grounding line parameterisation greatly improves performance, and that choice of a better grounding line parameterisation over a simpler one can bring further
improvements, in terms of both
accuracy and self consistent behaviour, comparable to increasing the grid resolution
by factor two (i.e. doubling the number of grid points).
The approach presented here to parameterising the grounding line does not completely
solve the grounding line problem, however it reduces the resolution required.
The parameterisations are presented
in the context of a one dimensional
"shelfy-stream" flow-line model, but could be extended to cope with more than one dimension
and other model formulations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|