Data assimilation using a hybrid ice flow model
Hybrid models, or depth-integrated flow models that include the effect of both longitudinal stresses and vertical shearing, are becoming more prevalent in dynamical ice modeling. Under a wide range of conditions they closely approximate the well-known First Order stress balance, yet are of computati...
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ftdoajarticles:oai:doaj.org/article:a1959e5533d44108962e6395703b76ff 2023-05-15T18:32:31+02:00 Data assimilation using a hybrid ice flow model D. N. Goldberg O. V. Sergienko 2011-04-01T00:00:00Z https://doi.org/10.5194/tc-5-315-2011 https://doaj.org/article/a1959e5533d44108962e6395703b76ff EN eng Copernicus Publications http://www.the-cryosphere.net/5/315/2011/tc-5-315-2011.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-5-315-2011 1994-0416 1994-0424 https://doaj.org/article/a1959e5533d44108962e6395703b76ff The Cryosphere, Vol 5, Iss 2, Pp 315-327 (2011) Environmental sciences GE1-350 Geology QE1-996.5 article 2011 ftdoajarticles https://doi.org/10.5194/tc-5-315-2011 2022-12-31T02:22:54Z Hybrid models, or depth-integrated flow models that include the effect of both longitudinal stresses and vertical shearing, are becoming more prevalent in dynamical ice modeling. Under a wide range of conditions they closely approximate the well-known First Order stress balance, yet are of computationally lower dimension, and thus require less intensive resources. Concomitant with the development and use of these models is the need to perform inversions of observed data. Here, an inverse control method is extended to use a hybrid flow model as a forward model. We derive an adjoint of a hybrid model and use it for inversion of ice-stream basal traction from observed surface velocities. A novel aspect of the adjoint derivation is a retention of non-linearities in Glen's flow law. Experiments show that in some cases, including those nonlinearities is advantageous in minimization of the cost function, yielding a more efficient inversion procedure. Article in Journal/Newspaper The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 5 2 315 327 |
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 D. N. Goldberg O. V. Sergienko Data assimilation using a hybrid ice flow model |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Hybrid models, or depth-integrated flow models that include the effect of both longitudinal stresses and vertical shearing, are becoming more prevalent in dynamical ice modeling. Under a wide range of conditions they closely approximate the well-known First Order stress balance, yet are of computationally lower dimension, and thus require less intensive resources. Concomitant with the development and use of these models is the need to perform inversions of observed data. Here, an inverse control method is extended to use a hybrid flow model as a forward model. We derive an adjoint of a hybrid model and use it for inversion of ice-stream basal traction from observed surface velocities. A novel aspect of the adjoint derivation is a retention of non-linearities in Glen's flow law. Experiments show that in some cases, including those nonlinearities is advantageous in minimization of the cost function, yielding a more efficient inversion procedure. |
format |
Article in Journal/Newspaper |
author |
D. N. Goldberg O. V. Sergienko |
author_facet |
D. N. Goldberg O. V. Sergienko |
author_sort |
D. N. Goldberg |
title |
Data assimilation using a hybrid ice flow model |
title_short |
Data assimilation using a hybrid ice flow model |
title_full |
Data assimilation using a hybrid ice flow model |
title_fullStr |
Data assimilation using a hybrid ice flow model |
title_full_unstemmed |
Data assimilation using a hybrid ice flow model |
title_sort |
data assimilation using a hybrid ice flow model |
publisher |
Copernicus Publications |
publishDate |
2011 |
url |
https://doi.org/10.5194/tc-5-315-2011 https://doaj.org/article/a1959e5533d44108962e6395703b76ff |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 5, Iss 2, Pp 315-327 (2011) |
op_relation |
http://www.the-cryosphere.net/5/315/2011/tc-5-315-2011.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-5-315-2011 1994-0416 1994-0424 https://doaj.org/article/a1959e5533d44108962e6395703b76ff |
op_doi |
https://doi.org/10.5194/tc-5-315-2011 |
container_title |
The Cryosphere |
container_volume |
5 |
container_issue |
2 |
container_start_page |
315 |
op_container_end_page |
327 |
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1766216635422605312 |