 |
| Titel |
Effect of uncertainty in surface mass balance–elevation feedback on projections of the future sea level contribution of the Greenland ice sheet |
| VerfasserIn |
T. L. Edwards, X. Fettweis, O. Gagliardini, F. Gillet-Chaulet, H. Goelzer, J. M. Gregory, M. Hoffman, P. Huybrechts, A. J. Payne, M. Perego, S. Price, A. Quiquet, C. Ritz |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 8, no. 1 ; Nr. 8, no. 1 (2014-01-30), S.195-208 |
| Datensatznummer |
250116016
|
| Publikation (Nr.) |
 copernicus.org/tc-8-195-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
We apply a new parameterisation of the Greenland ice sheet (GrIS)
feedback between surface mass balance (SMB: the sum of surface
accumulation and surface ablation) and surface elevation in the MAR
regional climate model (Edwards et al., 2014) to projections of future
climate change using five ice sheet models (ISMs). The MAR (Modèle Atmosphérique
Régional: Fettweis, 2007) climate
projections are for 2000–2199, forced by the ECHAM5 and HadCM3 global
climate models (GCMs) under the SRES A1B emissions scenario.
The additional sea level contribution due to the SMB–elevation
feedback averaged over five ISM projections for ECHAM5 and three for
HadCM3 is 4.3% (best estimate; 95% credibility
interval 1.8–6.9%) at 2100, and 9.6% (best
estimate; 95% credibility interval 3.6–16.0%) at
2200. In all results the elevation feedback is significantly positive,
amplifying the GrIS sea level contribution relative to the MAR
projections in which the ice sheet topography is fixed: the lower
bounds of our 95% credibility intervals (CIs) for sea level
contributions are larger than the "no feedback" case for all ISMs and
GCMs.
Our method is novel in sea level projections because we propagate
three types of modelling uncertainty – GCM and ISM structural
uncertainties, and elevation feedback parameterisation uncertainty –
along the causal chain, from SRES scenario to sea level, within
a coherent experimental design and statistical framework. The relative
contributions to uncertainty depend on the timescale of interest. At
2100, the GCM uncertainty is largest, but by 2200 both the ISM and
parameterisation uncertainties are larger. We also perform a perturbed
parameter ensemble with one ISM to estimate the shape of the projected
sea level probability distribution; our results indicate that the
probability density is slightly skewed towards higher sea level
contributions. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|