The transferability of adjoint inversion products between different ice flow models
Among the most important challenges faced by ice flow models is how to represent basal and rheological conditions, which are challenging to obtain from direct observations. A common practice is to use numerical inversions to calculate estimates for the unknown properties, but there are many possible...
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ftdoajarticles:oai:doaj.org/article:26df8115779547d4be4d2a29e87f5284 2023-05-15T13:24:16+02:00 The transferability of adjoint inversion products between different ice flow models J. M. Barnes T. Dias dos Santos D. Goldberg G. H. Gudmundsson M. Morlighem J. De Rydt 2021-04-01T00:00:00Z https://doi.org/10.5194/tc-15-1975-2021 https://doaj.org/article/26df8115779547d4be4d2a29e87f5284 EN eng Copernicus Publications https://tc.copernicus.org/articles/15/1975/2021/tc-15-1975-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-1975-2021 1994-0416 1994-0424 https://doaj.org/article/26df8115779547d4be4d2a29e87f5284 The Cryosphere, Vol 15, Pp 1975-2000 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-1975-2021 2022-12-31T04:07:54Z Among the most important challenges faced by ice flow models is how to represent basal and rheological conditions, which are challenging to obtain from direct observations. A common practice is to use numerical inversions to calculate estimates for the unknown properties, but there are many possible methods and not one standardised approach. As such, every ice flow model has a unique initialisation procedure. Here we compare the outputs of inversions from three different ice flow models, each employing a variant of adjoint-based optimisation to calculate basal sliding coefficients and flow rate factors using the same observed surface velocities and ice thickness distribution. The region we focus on is the Amundsen Sea Embayment in West Antarctica, the subject of much investigation due to rapid changes in the area over recent decades. We find that our inversions produce similar distributions of basal sliding across all models, despite using different techniques, implying that the methods used are highly robust and represent the physical equations without much influence by individual model behaviours. Transferring the products of inversions between models results in time-dependent simulations displaying variability on the order of or lower than existing model intercomparisons. Focusing on contributions to sea level, the highest variability we find in simulations run in the same model with different inversion products is 32 %, over a 40-year period, a difference of 3.67 mm . There is potential for this to be improved with further standardisation of modelling processes, and the lowest variability within a single model is 13 %, or 1.82 mm over 40 years. While the successful transfer of inversion outputs from one model to another requires some extra effort and technical knowledge of the particular models involved, it is certainly possible and could indeed be useful for future intercomparison projects. Article in Journal/Newspaper Amundsen Sea Antarc* Antarctica The Cryosphere West Antarctica Directory of Open Access Journals: DOAJ Articles West Antarctica Amundsen Sea The Cryosphere 15 4 1975 2000 |
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 J. M. Barnes T. Dias dos Santos D. Goldberg G. H. Gudmundsson M. Morlighem J. De Rydt The transferability of adjoint inversion products between different ice flow models |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Among the most important challenges faced by ice flow models is how to represent basal and rheological conditions, which are challenging to obtain from direct observations. A common practice is to use numerical inversions to calculate estimates for the unknown properties, but there are many possible methods and not one standardised approach. As such, every ice flow model has a unique initialisation procedure. Here we compare the outputs of inversions from three different ice flow models, each employing a variant of adjoint-based optimisation to calculate basal sliding coefficients and flow rate factors using the same observed surface velocities and ice thickness distribution. The region we focus on is the Amundsen Sea Embayment in West Antarctica, the subject of much investigation due to rapid changes in the area over recent decades. We find that our inversions produce similar distributions of basal sliding across all models, despite using different techniques, implying that the methods used are highly robust and represent the physical equations without much influence by individual model behaviours. Transferring the products of inversions between models results in time-dependent simulations displaying variability on the order of or lower than existing model intercomparisons. Focusing on contributions to sea level, the highest variability we find in simulations run in the same model with different inversion products is 32 %, over a 40-year period, a difference of 3.67 mm . There is potential for this to be improved with further standardisation of modelling processes, and the lowest variability within a single model is 13 %, or 1.82 mm over 40 years. While the successful transfer of inversion outputs from one model to another requires some extra effort and technical knowledge of the particular models involved, it is certainly possible and could indeed be useful for future intercomparison projects. |
format |
Article in Journal/Newspaper |
author |
J. M. Barnes T. Dias dos Santos D. Goldberg G. H. Gudmundsson M. Morlighem J. De Rydt |
author_facet |
J. M. Barnes T. Dias dos Santos D. Goldberg G. H. Gudmundsson M. Morlighem J. De Rydt |
author_sort |
J. M. Barnes |
title |
The transferability of adjoint inversion products between different ice flow models |
title_short |
The transferability of adjoint inversion products between different ice flow models |
title_full |
The transferability of adjoint inversion products between different ice flow models |
title_fullStr |
The transferability of adjoint inversion products between different ice flow models |
title_full_unstemmed |
The transferability of adjoint inversion products between different ice flow models |
title_sort |
transferability of adjoint inversion products between different ice flow models |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-1975-2021 https://doaj.org/article/26df8115779547d4be4d2a29e87f5284 |
geographic |
West Antarctica Amundsen Sea |
geographic_facet |
West Antarctica Amundsen Sea |
genre |
Amundsen Sea Antarc* Antarctica The Cryosphere West Antarctica |
genre_facet |
Amundsen Sea Antarc* Antarctica The Cryosphere West Antarctica |
op_source |
The Cryosphere, Vol 15, Pp 1975-2000 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/1975/2021/tc-15-1975-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-1975-2021 1994-0416 1994-0424 https://doaj.org/article/26df8115779547d4be4d2a29e87f5284 |
op_doi |
https://doi.org/10.5194/tc-15-1975-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
4 |
container_start_page |
1975 |
op_container_end_page |
2000 |
_version_ |
1766378434763685888 |