A new model of dry firn-densification constrained by continuous strain measurements near South Pole
Abstract Converting measurements of ice-sheet surface elevation change to mass change requires measurements of accumulation and knowledge of the evolution of the density profile in the firn. Most firn-densification models are tuned using measured depth–density profiles, a method which is based on an...
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2023
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Online Access: | http://dx.doi.org/10.1017/jog.2023.87 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000874 |
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crcambridgeupr:10.1017/jog.2023.87 2024-03-03T08:37:52+00:00 A new model of dry firn-densification constrained by continuous strain measurements near South Pole Stevens, C. Max Lilien, David A. Conway, Howard Fudge, T. J. Koutnik, Michelle R. Waddington, Edwin D. Division of Polar Programs 2023 http://dx.doi.org/10.1017/jog.2023.87 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000874 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology page 1-15 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 2023 crcambridgeupr https://doi.org/10.1017/jog.2023.87 2024-02-08T08:32:59Z Abstract Converting measurements of ice-sheet surface elevation change to mass change requires measurements of accumulation and knowledge of the evolution of the density profile in the firn. Most firn-densification models are tuned using measured depth–density profiles, a method which is based on an assumption that the density profile in the firn is invariant through time. Here we present continuous measurements of firn-compaction rates in 12 boreholes near the South Pole over a 2 year period. To our knowledge, these are the first continuous measurements of firn compaction on the Antarctic plateau. We use the data to derive a new firn-densification algorithm framed as a constitutive relationship. We also compare our measurements to compaction rates predicted by several existing firn-densification models. Results indicate that an activation energy of 60 kJ mol −1 , a value within the range used by current models, best predicts the seasonal cycle in compaction rates on the Antarctic plateau. Our results suggest models can predict firn-compaction rates with at best 7% uncertainty and cumulative firn compaction on a 2 year timescale with at best 8% uncertainty. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Journal of Glaciology South pole South pole Cambridge University Press Antarctic The Antarctic South Pole Journal of Glaciology 1 15 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Stevens, C. Max Lilien, David A. Conway, Howard Fudge, T. J. Koutnik, Michelle R. Waddington, Edwin D. A new model of dry firn-densification constrained by continuous strain measurements near South Pole |
topic_facet |
Earth-Surface Processes |
description |
Abstract Converting measurements of ice-sheet surface elevation change to mass change requires measurements of accumulation and knowledge of the evolution of the density profile in the firn. Most firn-densification models are tuned using measured depth–density profiles, a method which is based on an assumption that the density profile in the firn is invariant through time. Here we present continuous measurements of firn-compaction rates in 12 boreholes near the South Pole over a 2 year period. To our knowledge, these are the first continuous measurements of firn compaction on the Antarctic plateau. We use the data to derive a new firn-densification algorithm framed as a constitutive relationship. We also compare our measurements to compaction rates predicted by several existing firn-densification models. Results indicate that an activation energy of 60 kJ mol −1 , a value within the range used by current models, best predicts the seasonal cycle in compaction rates on the Antarctic plateau. Our results suggest models can predict firn-compaction rates with at best 7% uncertainty and cumulative firn compaction on a 2 year timescale with at best 8% uncertainty. |
author2 |
Division of Polar Programs |
format |
Article in Journal/Newspaper |
author |
Stevens, C. Max Lilien, David A. Conway, Howard Fudge, T. J. Koutnik, Michelle R. Waddington, Edwin D. |
author_facet |
Stevens, C. Max Lilien, David A. Conway, Howard Fudge, T. J. Koutnik, Michelle R. Waddington, Edwin D. |
author_sort |
Stevens, C. Max |
title |
A new model of dry firn-densification constrained by continuous strain measurements near South Pole |
title_short |
A new model of dry firn-densification constrained by continuous strain measurements near South Pole |
title_full |
A new model of dry firn-densification constrained by continuous strain measurements near South Pole |
title_fullStr |
A new model of dry firn-densification constrained by continuous strain measurements near South Pole |
title_full_unstemmed |
A new model of dry firn-densification constrained by continuous strain measurements near South Pole |
title_sort |
new model of dry firn-densification constrained by continuous strain measurements near south pole |
publisher |
Cambridge University Press (CUP) |
publishDate |
2023 |
url |
http://dx.doi.org/10.1017/jog.2023.87 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000874 |
geographic |
Antarctic The Antarctic South Pole |
geographic_facet |
Antarctic The Antarctic South Pole |
genre |
Antarc* Antarctic Ice Sheet Journal of Glaciology South pole South pole |
genre_facet |
Antarc* Antarctic Ice Sheet Journal of Glaciology South pole South pole |
op_source |
Journal of Glaciology page 1-15 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2023.87 |
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Journal of Glaciology |
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1 |
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15 |
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1792502452882243584 |