Reconstructing subglacial lake activity with an altimetry-based inverse method
Abstract Subglacial lake water-volume changes produce ice-elevation anomalies that provide clues about water flow beneath glaciers and ice sheets. Significant challenges remain in the quantitative interpretation of these elevation-change anomalies because the surface expression of subglacial lake ac...
Published in: | Journal of Glaciology |
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Cambridge University Press (CUP)
2023
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Online Access: | http://dx.doi.org/10.1017/jog.2023.90 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000904 |
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crcambridgeupr:10.1017/jog.2023.90 2024-10-13T14:03:00+00:00 Reconstructing subglacial lake activity with an altimetry-based inverse method Stubblefield, Aaron G. Meyer, Colin R. Siegfried, Matthew R. Sauthoff, Wilson Spiegelman, Marc National Aeronautics and Space Administration National Aeronautics and Space Administration Office of Polar Programs Army Research Office 2023 http://dx.doi.org/10.1017/jog.2023.90 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000904 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology page 1-15 ISSN 0022-1430 1727-5652 journal-article 2023 crcambridgeupr https://doi.org/10.1017/jog.2023.90 2024-09-18T04:01:43Z Abstract Subglacial lake water-volume changes produce ice-elevation anomalies that provide clues about water flow beneath glaciers and ice sheets. Significant challenges remain in the quantitative interpretation of these elevation-change anomalies because the surface expression of subglacial lake activity depends on basal conditions, rate of water-volume change, and ice rheology. To address these challenges, we introduce an inverse method that reconstructs subglacial lake activity from altimetry data while accounting for the effects of viscous ice flow. We use a linearized approximation of a Stokes ice-flow model under the assumption that subglacial lake activity only induces small perturbations relative to a reference ice-flow state. We validate this assumption by accurately reconstructing lake activity from synthetic data that are produced with a fully nonlinear model. We then apply the method to estimate the water-volume changes of several active subglacial lakes in Antarctica by inverting data from NASA's Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) laser altimetry mission. The results show that there can be substantial discrepancies (20% or more) between the inversion and traditional estimation methods due to the effects of viscous ice flow. The inverse method will help refine estimates of subglacial water transport and further constrain the role of subglacial hydrology in ice-sheet evolution. Article in Journal/Newspaper Antarc* Antarctica Ice Sheet Journal of Glaciology Cambridge University Press 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 |
description |
Abstract Subglacial lake water-volume changes produce ice-elevation anomalies that provide clues about water flow beneath glaciers and ice sheets. Significant challenges remain in the quantitative interpretation of these elevation-change anomalies because the surface expression of subglacial lake activity depends on basal conditions, rate of water-volume change, and ice rheology. To address these challenges, we introduce an inverse method that reconstructs subglacial lake activity from altimetry data while accounting for the effects of viscous ice flow. We use a linearized approximation of a Stokes ice-flow model under the assumption that subglacial lake activity only induces small perturbations relative to a reference ice-flow state. We validate this assumption by accurately reconstructing lake activity from synthetic data that are produced with a fully nonlinear model. We then apply the method to estimate the water-volume changes of several active subglacial lakes in Antarctica by inverting data from NASA's Ice, Cloud, and land Elevation Satellite 2 (ICESat-2) laser altimetry mission. The results show that there can be substantial discrepancies (20% or more) between the inversion and traditional estimation methods due to the effects of viscous ice flow. The inverse method will help refine estimates of subglacial water transport and further constrain the role of subglacial hydrology in ice-sheet evolution. |
author2 |
National Aeronautics and Space Administration National Aeronautics and Space Administration Office of Polar Programs Army Research Office |
format |
Article in Journal/Newspaper |
author |
Stubblefield, Aaron G. Meyer, Colin R. Siegfried, Matthew R. Sauthoff, Wilson Spiegelman, Marc |
spellingShingle |
Stubblefield, Aaron G. Meyer, Colin R. Siegfried, Matthew R. Sauthoff, Wilson Spiegelman, Marc Reconstructing subglacial lake activity with an altimetry-based inverse method |
author_facet |
Stubblefield, Aaron G. Meyer, Colin R. Siegfried, Matthew R. Sauthoff, Wilson Spiegelman, Marc |
author_sort |
Stubblefield, Aaron G. |
title |
Reconstructing subglacial lake activity with an altimetry-based inverse method |
title_short |
Reconstructing subglacial lake activity with an altimetry-based inverse method |
title_full |
Reconstructing subglacial lake activity with an altimetry-based inverse method |
title_fullStr |
Reconstructing subglacial lake activity with an altimetry-based inverse method |
title_full_unstemmed |
Reconstructing subglacial lake activity with an altimetry-based inverse method |
title_sort |
reconstructing subglacial lake activity with an altimetry-based inverse method |
publisher |
Cambridge University Press (CUP) |
publishDate |
2023 |
url |
http://dx.doi.org/10.1017/jog.2023.90 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000904 |
genre |
Antarc* Antarctica Ice Sheet Journal of Glaciology |
genre_facet |
Antarc* Antarctica Ice Sheet Journal of Glaciology |
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.2023.90 |
container_title |
Journal of Glaciology |
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1 |
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15 |
_version_ |
1812819445390770176 |