Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion
We present a novel thickness inversion approach that leverages satellite products and state-of-the-art ice flow models to produce distributed maps of sub-glacial topography consistent with the dynamic state of a given glacier. While the method can use any complexity of ice flow physics as represente...
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Language: | English |
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Copernicus Publications
2023
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Online Access: | https://doi.org/10.5194/tc-17-4021-2023 https://doaj.org/article/7eb04604c62c47779640f4261612987d |
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ftdoajarticles:oai:doaj.org/article:7eb04604c62c47779640f4261612987d 2023-10-09T21:51:48+02:00 Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion T. Frank W. J. J. van Pelt J. Kohler 2023-09-01T00:00:00Z https://doi.org/10.5194/tc-17-4021-2023 https://doaj.org/article/7eb04604c62c47779640f4261612987d EN eng Copernicus Publications https://tc.copernicus.org/articles/17/4021/2023/tc-17-4021-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-4021-2023 1994-0416 1994-0424 https://doaj.org/article/7eb04604c62c47779640f4261612987d The Cryosphere, Vol 17, Pp 4021-4045 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-4021-2023 2023-09-24T00:42:23Z We present a novel thickness inversion approach that leverages satellite products and state-of-the-art ice flow models to produce distributed maps of sub-glacial topography consistent with the dynamic state of a given glacier. While the method can use any complexity of ice flow physics as represented in ice dynamical models, it is computationally cheap and does not require bed observations as input, enabling applications on both local and large scales. Using the mismatch between observed and modelled rates of surface elevation change ( d h / d t <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="6475a6b5411bf125092ba330d7bb10e8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-17-4021-2023-ie00001.svg" width="31pt" height="14pt" src="tc-17-4021-2023-ie00001.png"/></svg:svg> ) as the misfit functional, iterative point-wise updates to an initial guess of bed topography are made, while mismatches between observed and modelled velocities are used to simultaneously infer basal friction. The final product of the inversion is not only a map of ice thickness, but is also a fully spun-up glacier model that can be run forward without requiring any further model relaxation. Here we present the method and use an artificial ice cap built inside a numerical model to test it and conduct sensitivity experiments. Even under a range of perturbations, the method is stable and fast. We also apply the approach to the tidewater glacier Kronebreen on Svalbard and finally benchmark it on glaciers from the Ice Thickness Models Intercomparison eXperiment (ITMIX, Farinotti et al. , 2017 ) , where we find excellent performance. Ultimately, our method shown here represents a fast way of inferring ice thickness where the final output forms a consistent picture of model physics, input observations and bed topography. Article in Journal/Newspaper glacier Ice cap Svalbard The Cryosphere Tidewater Directory of Open Access Journals: DOAJ Articles Kronebreen ENVELOPE(13.333,13.333,78.833,78.833) Svalbard The Cryosphere 17 9 4021 4045 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 T. Frank W. J. J. van Pelt J. Kohler Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
We present a novel thickness inversion approach that leverages satellite products and state-of-the-art ice flow models to produce distributed maps of sub-glacial topography consistent with the dynamic state of a given glacier. While the method can use any complexity of ice flow physics as represented in ice dynamical models, it is computationally cheap and does not require bed observations as input, enabling applications on both local and large scales. Using the mismatch between observed and modelled rates of surface elevation change ( d h / d t <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="31pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="6475a6b5411bf125092ba330d7bb10e8"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-17-4021-2023-ie00001.svg" width="31pt" height="14pt" src="tc-17-4021-2023-ie00001.png"/></svg:svg> ) as the misfit functional, iterative point-wise updates to an initial guess of bed topography are made, while mismatches between observed and modelled velocities are used to simultaneously infer basal friction. The final product of the inversion is not only a map of ice thickness, but is also a fully spun-up glacier model that can be run forward without requiring any further model relaxation. Here we present the method and use an artificial ice cap built inside a numerical model to test it and conduct sensitivity experiments. Even under a range of perturbations, the method is stable and fast. We also apply the approach to the tidewater glacier Kronebreen on Svalbard and finally benchmark it on glaciers from the Ice Thickness Models Intercomparison eXperiment (ITMIX, Farinotti et al. , 2017 ) , where we find excellent performance. Ultimately, our method shown here represents a fast way of inferring ice thickness where the final output forms a consistent picture of model physics, input observations and bed topography. |
format |
Article in Journal/Newspaper |
author |
T. Frank W. J. J. van Pelt J. Kohler |
author_facet |
T. Frank W. J. J. van Pelt J. Kohler |
author_sort |
T. Frank |
title |
Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion |
title_short |
Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion |
title_full |
Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion |
title_fullStr |
Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion |
title_full_unstemmed |
Reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion |
title_sort |
reconciling ice dynamics and bed topography with a versatile and fast ice thickness inversion |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-4021-2023 https://doaj.org/article/7eb04604c62c47779640f4261612987d |
long_lat |
ENVELOPE(13.333,13.333,78.833,78.833) |
geographic |
Kronebreen Svalbard |
geographic_facet |
Kronebreen Svalbard |
genre |
glacier Ice cap Svalbard The Cryosphere Tidewater |
genre_facet |
glacier Ice cap Svalbard The Cryosphere Tidewater |
op_source |
The Cryosphere, Vol 17, Pp 4021-4045 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/4021/2023/tc-17-4021-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-4021-2023 1994-0416 1994-0424 https://doaj.org/article/7eb04604c62c47779640f4261612987d |
op_doi |
https://doi.org/10.5194/tc-17-4021-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
9 |
container_start_page |
4021 |
op_container_end_page |
4045 |
_version_ |
1779314910017093632 |