Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis
The Parallel Ice Sheet Model (PISM) is applied to the Antarctic Ice Sheet over the last two glacial cycles (≈210 000 years) with a resolution of 16 km. An ensemble of 256 model runs is analyzed in which four relevant model parameters have been systematically varied using full-factorial parameter sam...
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Copernicus Publications (EGU)
2020
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Online Access: | https://oceanrep.geomar.de/id/eprint/54744/ https://oceanrep.geomar.de/id/eprint/54744/1/tc-14-633-2020.pdf https://doi.org/10.5194/tc-14-633-2020 |
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ftoceanrep:oai:oceanrep.geomar.de:54744 2023-08-27T04:04:07+02:00 Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis Albrecht, Torsten Winkelmann, Ricarda Levermann, Anders 2020-02-14 text https://oceanrep.geomar.de/id/eprint/54744/ https://oceanrep.geomar.de/id/eprint/54744/1/tc-14-633-2020.pdf https://doi.org/10.5194/tc-14-633-2020 en eng Copernicus Publications (EGU) https://oceanrep.geomar.de/id/eprint/54744/1/tc-14-633-2020.pdf Albrecht, T., Winkelmann, R. and Levermann, A. (2020) Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis. Open Access The Cryosphere, 14 (2). pp. 633-656. DOI 10.5194/tc-14-633-2020 <https://doi.org/10.5194/tc-14-633-2020>. doi:10.5194/tc-14-633-2020 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2020 ftoceanrep https://doi.org/10.5194/tc-14-633-2020 2023-08-06T23:19:54Z The Parallel Ice Sheet Model (PISM) is applied to the Antarctic Ice Sheet over the last two glacial cycles (≈210 000 years) with a resolution of 16 km. An ensemble of 256 model runs is analyzed in which four relevant model parameters have been systematically varied using full-factorial parameter sampling. Parameters and plausible parameter ranges have been identified in a companion paper (Albrecht et al., 2020) and are associated with ice dynamics, climatic forcing, basal sliding and bed deformation and represent distinct classes of model uncertainties. The model is scored against both modern and geologic data, including reconstructed grounding-line locations, elevation–age data, ice thickness, surface velocities and uplift rates. An aggregated score is computed for each ensemble member that measures the overall model–data misfit, including measurement uncertainty in terms of a Gaussian error model (Briggs and Tarasov, 2013). The statistical method used to analyze the ensemble simulation results follows closely the simple averaging method described in Pollard et al. (2016). This analysis reveals clusters of best-fit parameter combinations, and hence a likely range of relevant model and boundary parameters, rather than individual best-fit parameters. The ensemble of reconstructed histories of Antarctic Ice Sheet volumes provides a score-weighted likely range of sea-level contributions since the Last Glacial Maximum (LGM) of 9.4±4.1 m (or 6.5±2.0×106km3 ), which is at the upper range of most previous studies. The last deglaciation occurs in all ensemble simulations after around 12 000 years before present and hence after the meltwater pulse 1A (MWP1a). Our ensemble analysis also provides an estimate of parametric uncertainty bounds for the present-day state that can be used for PISM projections of future sea-level contributions from the Antarctic Ice Sheet. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet The Cryosphere OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Briggs ENVELOPE(-63.017,-63.017,-64.517,-64.517) Pollard ENVELOPE(64.617,64.617,-70.467,-70.467) The Antarctic The Cryosphere 14 2 633 656 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
The Parallel Ice Sheet Model (PISM) is applied to the Antarctic Ice Sheet over the last two glacial cycles (≈210 000 years) with a resolution of 16 km. An ensemble of 256 model runs is analyzed in which four relevant model parameters have been systematically varied using full-factorial parameter sampling. Parameters and plausible parameter ranges have been identified in a companion paper (Albrecht et al., 2020) and are associated with ice dynamics, climatic forcing, basal sliding and bed deformation and represent distinct classes of model uncertainties. The model is scored against both modern and geologic data, including reconstructed grounding-line locations, elevation–age data, ice thickness, surface velocities and uplift rates. An aggregated score is computed for each ensemble member that measures the overall model–data misfit, including measurement uncertainty in terms of a Gaussian error model (Briggs and Tarasov, 2013). The statistical method used to analyze the ensemble simulation results follows closely the simple averaging method described in Pollard et al. (2016). This analysis reveals clusters of best-fit parameter combinations, and hence a likely range of relevant model and boundary parameters, rather than individual best-fit parameters. The ensemble of reconstructed histories of Antarctic Ice Sheet volumes provides a score-weighted likely range of sea-level contributions since the Last Glacial Maximum (LGM) of 9.4±4.1 m (or 6.5±2.0×106km3 ), which is at the upper range of most previous studies. The last deglaciation occurs in all ensemble simulations after around 12 000 years before present and hence after the meltwater pulse 1A (MWP1a). Our ensemble analysis also provides an estimate of parametric uncertainty bounds for the present-day state that can be used for PISM projections of future sea-level contributions from the Antarctic Ice Sheet. |
format |
Article in Journal/Newspaper |
author |
Albrecht, Torsten Winkelmann, Ricarda Levermann, Anders |
spellingShingle |
Albrecht, Torsten Winkelmann, Ricarda Levermann, Anders Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis |
author_facet |
Albrecht, Torsten Winkelmann, Ricarda Levermann, Anders |
author_sort |
Albrecht, Torsten |
title |
Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis |
title_short |
Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis |
title_full |
Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis |
title_fullStr |
Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis |
title_full_unstemmed |
Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis |
title_sort |
glacial-cycle simulations of the antarctic ice sheet with the parallel ice sheet model (pism) – part 2: parameter ensemble analysis |
publisher |
Copernicus Publications (EGU) |
publishDate |
2020 |
url |
https://oceanrep.geomar.de/id/eprint/54744/ https://oceanrep.geomar.de/id/eprint/54744/1/tc-14-633-2020.pdf https://doi.org/10.5194/tc-14-633-2020 |
long_lat |
ENVELOPE(-63.017,-63.017,-64.517,-64.517) ENVELOPE(64.617,64.617,-70.467,-70.467) |
geographic |
Antarctic Briggs Pollard The Antarctic |
geographic_facet |
Antarctic Briggs Pollard The Antarctic |
genre |
Antarc* Antarctic Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet The Cryosphere |
op_relation |
https://oceanrep.geomar.de/id/eprint/54744/1/tc-14-633-2020.pdf Albrecht, T., Winkelmann, R. and Levermann, A. (2020) Glacial-cycle simulations of the Antarctic Ice Sheet with the Parallel Ice Sheet Model (PISM) – Part 2: Parameter ensemble analysis. Open Access The Cryosphere, 14 (2). pp. 633-656. DOI 10.5194/tc-14-633-2020 <https://doi.org/10.5194/tc-14-633-2020>. doi:10.5194/tc-14-633-2020 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-14-633-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
2 |
container_start_page |
633 |
op_container_end_page |
656 |
_version_ |
1775349511759069184 |