Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet
We present a new parameterisation that relates surface mass balance (SMB: the sum of surface accumulation and surface ablation) to changes in surface elevation of the Greenland ice sheet (GrIS) for the MAR (Modèle Atmosphérique Régional: Fettweis, 2007) regional climate model. The motivation is to d...
Published in: | The Cryosphere |
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Format: | Article in Journal/Newspaper |
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Copernicus Publications
2014
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Online Access: | https://doi.org/10.5194/tc-8-181-2014 http://www.the-cryosphere.net/8/181/2014/tc-8-181-2014.pdf https://doaj.org/article/a6208acf7d4a486eb6dbb6703f3b2e41 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:a6208acf7d4a486eb6dbb6703f3b2e41 2023-05-15T16:28:43+02:00 Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet 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 2014-01-01 https://doi.org/10.5194/tc-8-181-2014 http://www.the-cryosphere.net/8/181/2014/tc-8-181-2014.pdf https://doaj.org/article/a6208acf7d4a486eb6dbb6703f3b2e41 en eng Copernicus Publications 1994-0416 1994-0424 doi:10.5194/tc-8-181-2014 http://www.the-cryosphere.net/8/181/2014/tc-8-181-2014.pdf https://doaj.org/article/a6208acf7d4a486eb6dbb6703f3b2e41 undefined The Cryosphere, Vol 8, Iss 1, Pp 181-194 (2014) envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2014 fttriple https://doi.org/10.5194/tc-8-181-2014 2023-01-22T19:32:29Z We present a new parameterisation that relates surface mass balance (SMB: the sum of surface accumulation and surface ablation) to changes in surface elevation of the Greenland ice sheet (GrIS) for the MAR (Modèle Atmosphérique Régional: Fettweis, 2007) regional climate model. The motivation is to dynamically adjust SMB as the GrIS evolves, allowing us to force ice sheet models with SMB simulated by MAR while incorporating the SMB–elevation feedback, without the substantial technical challenges of coupling ice sheet and climate models. This also allows us to assess the effect of elevation feedback uncertainty on the GrIS contribution to sea level, using multiple global climate and ice sheet models, without the need for additional, expensive MAR simulations. We estimate this relationship separately below and above the equilibrium line altitude (ELA, separating negative and positive SMB) and for regions north and south of 77° N, from a set of MAR simulations in which we alter the ice sheet surface elevation. These give four "SMB lapse rates", gradients that relate SMB changes to elevation changes. We assess uncertainties within a Bayesian framework, estimating probability distributions for each gradient from which we present best estimates and credibility intervals (CI) that bound 95% of the probability. Below the ELA our gradient estimates are mostly positive, because SMB usually increases with elevation: 0.56 (95% CI: −0.22 to 1.33) kg m−3 a−1 for the north, and 1.91 (1.03 to 2.61) kg m−3 a−1 for the south. Above the ELA, the gradients are much smaller in magnitude: 0.09 (−0.03 to 0.23) kg m−3 a−1 in the north, and 0.07 (−0.07 to 0.59) kg m−3 a−1 in the south, because SMB can either increase or decrease in response to increased elevation. Our statistically founded approach allows us to make probabilistic assessments for the effect of elevation feedback uncertainty on sea level projections (Edwards et al., 2014). Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere Unknown Ela ENVELOPE(9.642,9.642,63.170,63.170) Greenland The Cryosphere 8 1 181 194 |
institution |
Open Polar |
collection |
Unknown |
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fttriple |
language |
English |
topic |
envir geo |
spellingShingle |
envir geo 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 Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet |
topic_facet |
envir geo |
description |
We present a new parameterisation that relates surface mass balance (SMB: the sum of surface accumulation and surface ablation) to changes in surface elevation of the Greenland ice sheet (GrIS) for the MAR (Modèle Atmosphérique Régional: Fettweis, 2007) regional climate model. The motivation is to dynamically adjust SMB as the GrIS evolves, allowing us to force ice sheet models with SMB simulated by MAR while incorporating the SMB–elevation feedback, without the substantial technical challenges of coupling ice sheet and climate models. This also allows us to assess the effect of elevation feedback uncertainty on the GrIS contribution to sea level, using multiple global climate and ice sheet models, without the need for additional, expensive MAR simulations. We estimate this relationship separately below and above the equilibrium line altitude (ELA, separating negative and positive SMB) and for regions north and south of 77° N, from a set of MAR simulations in which we alter the ice sheet surface elevation. These give four "SMB lapse rates", gradients that relate SMB changes to elevation changes. We assess uncertainties within a Bayesian framework, estimating probability distributions for each gradient from which we present best estimates and credibility intervals (CI) that bound 95% of the probability. Below the ELA our gradient estimates are mostly positive, because SMB usually increases with elevation: 0.56 (95% CI: −0.22 to 1.33) kg m−3 a−1 for the north, and 1.91 (1.03 to 2.61) kg m−3 a−1 for the south. Above the ELA, the gradients are much smaller in magnitude: 0.09 (−0.03 to 0.23) kg m−3 a−1 in the north, and 0.07 (−0.07 to 0.59) kg m−3 a−1 in the south, because SMB can either increase or decrease in response to increased elevation. Our statistically founded approach allows us to make probabilistic assessments for the effect of elevation feedback uncertainty on sea level projections (Edwards et al., 2014). |
format |
Article in Journal/Newspaper |
author |
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 |
author_facet |
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 |
author_sort |
T. L. Edwards |
title |
Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet |
title_short |
Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet |
title_full |
Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet |
title_fullStr |
Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet |
title_full_unstemmed |
Probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the Greenland ice sheet |
title_sort |
probabilistic parameterisation of the surface mass balance–elevation feedback in regional climate model simulations of the greenland ice sheet |
publisher |
Copernicus Publications |
publishDate |
2014 |
url |
https://doi.org/10.5194/tc-8-181-2014 http://www.the-cryosphere.net/8/181/2014/tc-8-181-2014.pdf https://doaj.org/article/a6208acf7d4a486eb6dbb6703f3b2e41 |
long_lat |
ENVELOPE(9.642,9.642,63.170,63.170) |
geographic |
Ela Greenland |
geographic_facet |
Ela Greenland |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 8, Iss 1, Pp 181-194 (2014) |
op_relation |
1994-0416 1994-0424 doi:10.5194/tc-8-181-2014 http://www.the-cryosphere.net/8/181/2014/tc-8-181-2014.pdf https://doaj.org/article/a6208acf7d4a486eb6dbb6703f3b2e41 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-8-181-2014 |
container_title |
The Cryosphere |
container_volume |
8 |
container_issue |
1 |
container_start_page |
181 |
op_container_end_page |
194 |
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1766018390946742272 |