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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ftleibnizopen:oai:oai.leibnizopen.de:gfVC-IYBdbrxVwz6fr2_ 2023-05-15T13:48:54+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 application/pdf https://oa.tib.eu/renate/handle/123456789/10022 https://doi.org/10.34657/9060 eng eng Katlenburg-Lindau : Copernicus CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0/ The Cryosphere : TC 14 (2020), Nr. 2 glacial-interglacial cycle last deglaciation Last Glacial Maximum meltwater parameter estimation 910 article Text 2020 ftleibnizopen https://doi.org/10.34657/9060 2023-03-20T00:28:21Z 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. publishedVersion Article in Journal/Newspaper Antarc* Antarctic Ice Sheet The Cryosphere LeibnizOpen (The Leibniz Association) Antarctic The Antarctic Briggs ENVELOPE(-63.017,-63.017,-64.517,-64.517) Pollard ENVELOPE(64.617,64.617,-70.467,-70.467) |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
glacial-interglacial cycle last deglaciation Last Glacial Maximum meltwater parameter estimation 910 |
spellingShingle |
glacial-interglacial cycle last deglaciation Last Glacial Maximum meltwater parameter estimation 910 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 |
topic_facet |
glacial-interglacial cycle last deglaciation Last Glacial Maximum meltwater parameter estimation 910 |
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. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Albrecht, Torsten Winkelmann, Ricarda Levermann, Anders |
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 |
Katlenburg-Lindau : Copernicus |
publishDate |
2020 |
url |
https://oa.tib.eu/renate/handle/123456789/10022 https://doi.org/10.34657/9060 |
long_lat |
ENVELOPE(-63.017,-63.017,-64.517,-64.517) ENVELOPE(64.617,64.617,-70.467,-70.467) |
geographic |
Antarctic The Antarctic Briggs Pollard |
geographic_facet |
Antarctic The Antarctic Briggs Pollard |
genre |
Antarc* Antarctic Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet The Cryosphere |
op_source |
The Cryosphere : TC 14 (2020), Nr. 2 |
op_rights |
CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.34657/9060 |
_version_ |
1766249947820195840 |