Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques
A 3-D hybrid ice-sheet model is applied to the last deglacial retreat of the West Antarctic Ice Sheet over the last ∼ 20 000 yr. A large ensemble of 625 model runs is used to calibrate the model to modern and geologic data, including reconstructed grounding lines, relative sea-level records, elevati...
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ftunivmassamh:oai:scholarworks.umass.edu:geo_faculty_pubs-1004 2023-05-15T13:53:29+02:00 Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques Pollard, David Chang, Won Haran, Murali Applegate, Patrick DeConto, Robert 2016-01-01T08:00:00Z application/pdf https://scholarworks.umass.edu/geo_faculty_pubs/5 https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1004&context=geo_faculty_pubs unknown ScholarWorks@UMass Amherst https://scholarworks.umass.edu/geo_faculty_pubs/5 https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1004&context=geo_faculty_pubs http://creativecommons.org/licenses/by/3.0/ CC-BY Geosciences Department Faculty Publication Series Earth Sciences Glaciology Other Earth Sciences text 2016 ftunivmassamh 2022-01-10T06:53:52Z A 3-D hybrid ice-sheet model is applied to the last deglacial retreat of the West Antarctic Ice Sheet over the last ∼ 20 000 yr. A large ensemble of 625 model runs is used to calibrate the model to modern and geologic data, including reconstructed grounding lines, relative sea-level records, elevation–age data and uplift rates, with an aggregate score computed for each run that measures overall model–data misfit. Two types of statistical methods are used to analyze the large-ensemble results: simple averaging weighted by the aggregate score, and more advanced Bayesian techniques involving Gaussian process-based emulation and calibration, and Markov chain Monte Carlo. The analyses provide sea-level-rise envelopes with well-defined parametric uncertainty bounds, but the simple averaging method only provides robust results with full-factorial parameter sampling in the large ensemble. Results for best-fit parameter ranges and envelopes of equivalent sea-level rise with the simple averaging method agree well with the more advanced techniques. Best-fit parameter ranges confirm earlier values expected from prior model tuning, including large basal sliding coefficients on modern ocean beds. Text Antarc* Antarctic Ice Sheet University of Massachusetts: ScholarWorks@UMass Amherst Antarctic West Antarctic Ice Sheet |
institution |
Open Polar |
collection |
University of Massachusetts: ScholarWorks@UMass Amherst |
op_collection_id |
ftunivmassamh |
language |
unknown |
topic |
Earth Sciences Glaciology Other Earth Sciences |
spellingShingle |
Earth Sciences Glaciology Other Earth Sciences Pollard, David Chang, Won Haran, Murali Applegate, Patrick DeConto, Robert Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques |
topic_facet |
Earth Sciences Glaciology Other Earth Sciences |
description |
A 3-D hybrid ice-sheet model is applied to the last deglacial retreat of the West Antarctic Ice Sheet over the last ∼ 20 000 yr. A large ensemble of 625 model runs is used to calibrate the model to modern and geologic data, including reconstructed grounding lines, relative sea-level records, elevation–age data and uplift rates, with an aggregate score computed for each run that measures overall model–data misfit. Two types of statistical methods are used to analyze the large-ensemble results: simple averaging weighted by the aggregate score, and more advanced Bayesian techniques involving Gaussian process-based emulation and calibration, and Markov chain Monte Carlo. The analyses provide sea-level-rise envelopes with well-defined parametric uncertainty bounds, but the simple averaging method only provides robust results with full-factorial parameter sampling in the large ensemble. Results for best-fit parameter ranges and envelopes of equivalent sea-level rise with the simple averaging method agree well with the more advanced techniques. Best-fit parameter ranges confirm earlier values expected from prior model tuning, including large basal sliding coefficients on modern ocean beds. |
format |
Text |
author |
Pollard, David Chang, Won Haran, Murali Applegate, Patrick DeConto, Robert |
author_facet |
Pollard, David Chang, Won Haran, Murali Applegate, Patrick DeConto, Robert |
author_sort |
Pollard, David |
title |
Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques |
title_short |
Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques |
title_full |
Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques |
title_fullStr |
Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques |
title_full_unstemmed |
Large Ensemble Modeling of the Last Deglacial Retreat of the West Antarctic Ice Sheet: Comparison of Simple and Advanced Statistical Techniques |
title_sort |
large ensemble modeling of the last deglacial retreat of the west antarctic ice sheet: comparison of simple and advanced statistical techniques |
publisher |
ScholarWorks@UMass Amherst |
publishDate |
2016 |
url |
https://scholarworks.umass.edu/geo_faculty_pubs/5 https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1004&context=geo_faculty_pubs |
geographic |
Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_source |
Geosciences Department Faculty Publication Series |
op_relation |
https://scholarworks.umass.edu/geo_faculty_pubs/5 https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1004&context=geo_faculty_pubs |
op_rights |
http://creativecommons.org/licenses/by/3.0/ |
op_rightsnorm |
CC-BY |
_version_ |
1766258635165401088 |