Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration
A glacial flow model of Smith, Pope and Kohler Glaciers is calibrated by means of control methods against time varying, annually resolved observations of ice height and velocities, covering the period 2002 to 2011. The inversion – termed "transient calibration" – produces an optimal set of...
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Copernicus Publications
2015
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Online Access: | https://doi.org/10.5194/tc-9-2429-2015 http://www.the-cryosphere.net/9/2429/2015/tc-9-2429-2015.pdf https://doaj.org/article/e6ccb3c28a2c49ed92ccfaea0a5954af |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:e6ccb3c28a2c49ed92ccfaea0a5954af 2023-05-15T18:32:23+02:00 Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration D. N. Goldberg P. Heimbach I. Joughin B. Smith 2015-12-01 https://doi.org/10.5194/tc-9-2429-2015 http://www.the-cryosphere.net/9/2429/2015/tc-9-2429-2015.pdf https://doaj.org/article/e6ccb3c28a2c49ed92ccfaea0a5954af en eng Copernicus Publications 1994-0416 1994-0424 doi:10.5194/tc-9-2429-2015 http://www.the-cryosphere.net/9/2429/2015/tc-9-2429-2015.pdf https://doaj.org/article/e6ccb3c28a2c49ed92ccfaea0a5954af undefined The Cryosphere, Vol 9, Iss 6, Pp 2429-2446 (2015) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2015 fttriple https://doi.org/10.5194/tc-9-2429-2015 2023-01-22T19:24:34Z A glacial flow model of Smith, Pope and Kohler Glaciers is calibrated by means of control methods against time varying, annually resolved observations of ice height and velocities, covering the period 2002 to 2011. The inversion – termed "transient calibration" – produces an optimal set of time-mean, spatially varying parameters together with a time-evolving state that accounts for the transient nature of observations and the model dynamics. Serving as an optimal initial condition, the estimated state for 2011 is used, with no additional forcing, for predicting grounded ice volume loss and grounding line retreat over the ensuing 30 years. The transiently calibrated model predicts a near-steady loss of grounded ice volume of approximately 21 km3 a−1 over this period, as well as loss of 33 km2 a−1 grounded area. We contrast this prediction with one obtained following a commonly used "snapshot" or steady-state inversion, which does not consider time dependence and assumes all observations to be contemporaneous. Transient calibration is shown to achieve a better fit with observations of thinning and grounding line retreat histories, and yields a quantitatively different projection with respect to ice volume loss and ungrounding. Sensitivity studies suggest large near-future levels of unforced, i.e., committed sea level contribution from these ice streams under reasonable assumptions regarding uncertainties of the unknown parameters. Article in Journal/Newspaper The Cryosphere Unknown The Cryosphere 9 6 2429 2446 |
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geo envir D. N. Goldberg P. Heimbach I. Joughin B. Smith Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration |
topic_facet |
geo envir |
description |
A glacial flow model of Smith, Pope and Kohler Glaciers is calibrated by means of control methods against time varying, annually resolved observations of ice height and velocities, covering the period 2002 to 2011. The inversion – termed "transient calibration" – produces an optimal set of time-mean, spatially varying parameters together with a time-evolving state that accounts for the transient nature of observations and the model dynamics. Serving as an optimal initial condition, the estimated state for 2011 is used, with no additional forcing, for predicting grounded ice volume loss and grounding line retreat over the ensuing 30 years. The transiently calibrated model predicts a near-steady loss of grounded ice volume of approximately 21 km3 a−1 over this period, as well as loss of 33 km2 a−1 grounded area. We contrast this prediction with one obtained following a commonly used "snapshot" or steady-state inversion, which does not consider time dependence and assumes all observations to be contemporaneous. Transient calibration is shown to achieve a better fit with observations of thinning and grounding line retreat histories, and yields a quantitatively different projection with respect to ice volume loss and ungrounding. Sensitivity studies suggest large near-future levels of unforced, i.e., committed sea level contribution from these ice streams under reasonable assumptions regarding uncertainties of the unknown parameters. |
format |
Article in Journal/Newspaper |
author |
D. N. Goldberg P. Heimbach I. Joughin B. Smith |
author_facet |
D. N. Goldberg P. Heimbach I. Joughin B. Smith |
author_sort |
D. N. Goldberg |
title |
Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration |
title_short |
Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration |
title_full |
Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration |
title_fullStr |
Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration |
title_full_unstemmed |
Committed retreat of Smith, Pope, and Kohler Glaciers over the next 30 years inferred by transient model calibration |
title_sort |
committed retreat of smith, pope, and kohler glaciers over the next 30 years inferred by transient model calibration |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/tc-9-2429-2015 http://www.the-cryosphere.net/9/2429/2015/tc-9-2429-2015.pdf https://doaj.org/article/e6ccb3c28a2c49ed92ccfaea0a5954af |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 9, Iss 6, Pp 2429-2446 (2015) |
op_relation |
1994-0416 1994-0424 doi:10.5194/tc-9-2429-2015 http://www.the-cryosphere.net/9/2429/2015/tc-9-2429-2015.pdf https://doaj.org/article/e6ccb3c28a2c49ed92ccfaea0a5954af |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-9-2429-2015 |
container_title |
The Cryosphere |
container_volume |
9 |
container_issue |
6 |
container_start_page |
2429 |
op_container_end_page |
2446 |
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1766216485975359488 |