Parameter and state estimation with a time-dependent adjoint marine ice sheet model
To date, assimilation of observations into large-scale ice models has consisted predominantly of time-independent inversions of surface velocities for basal traction, bed elevation, or ice stiffness, and has relied primarily on analytically derived adjoints of glaciological stress balance models. To...
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ftdoajarticles:oai:doaj.org/article:bddcb24761e94074a5b03aae1380441c 2023-05-15T16:40:22+02:00 Parameter and state estimation with a time-dependent adjoint marine ice sheet model D. N. Goldberg P. Heimbach 2013-11-01T00:00:00Z https://doi.org/10.5194/tc-7-1659-2013 https://doaj.org/article/bddcb24761e94074a5b03aae1380441c EN eng Copernicus Publications http://www.the-cryosphere.net/7/1659/2013/tc-7-1659-2013.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-7-1659-2013 https://doaj.org/article/bddcb24761e94074a5b03aae1380441c The Cryosphere, Vol 7, Iss 6, Pp 1659-1678 (2013) Environmental sciences GE1-350 Geology QE1-996.5 article 2013 ftdoajarticles https://doi.org/10.5194/tc-7-1659-2013 2022-12-31T02:14:53Z To date, assimilation of observations into large-scale ice models has consisted predominantly of time-independent inversions of surface velocities for basal traction, bed elevation, or ice stiffness, and has relied primarily on analytically derived adjoints of glaciological stress balance models. To overcome limitations of such "snapshot" inversions – i.e., their inability to assimilate time-dependent data for the purpose of constraining transient flow states, or to produce initial states with minimum artificial drift and suitable for time-dependent simulations – we have developed an adjoint of a time-dependent parallel glaciological flow model. The model implements a hybrid shallow shelf–shallow ice stress balance, solves the continuity equation for ice thickness evolution, and can represent the floating, fast-sliding, and frozen bed regimes of a marine ice sheet. The adjoint is generated by a combination of analytic methods and the use of algorithmic differentiation (AD) software. Several experiments are carried out with idealized geometries and synthetic observations, including inversion of time-dependent surface elevations for past thicknesses, and simultaneous retrieval of basal traction and topography from surface data. Flexible generation of the adjoint for a range of independent uncertain variables is exemplified through sensitivity calculations of grounded ice volume to changes in basal melting of floating and basal sliding of grounded ice. The results are encouraging and suggest the feasibility, using real observations, of improved ice sheet state estimation and comprehensive transient sensitivity assessments. Article in Journal/Newspaper Ice Sheet The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 7 6 1659 1678 |
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 P. Heimbach Parameter and state estimation with a time-dependent adjoint marine ice sheet model |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
To date, assimilation of observations into large-scale ice models has consisted predominantly of time-independent inversions of surface velocities for basal traction, bed elevation, or ice stiffness, and has relied primarily on analytically derived adjoints of glaciological stress balance models. To overcome limitations of such "snapshot" inversions – i.e., their inability to assimilate time-dependent data for the purpose of constraining transient flow states, or to produce initial states with minimum artificial drift and suitable for time-dependent simulations – we have developed an adjoint of a time-dependent parallel glaciological flow model. The model implements a hybrid shallow shelf–shallow ice stress balance, solves the continuity equation for ice thickness evolution, and can represent the floating, fast-sliding, and frozen bed regimes of a marine ice sheet. The adjoint is generated by a combination of analytic methods and the use of algorithmic differentiation (AD) software. Several experiments are carried out with idealized geometries and synthetic observations, including inversion of time-dependent surface elevations for past thicknesses, and simultaneous retrieval of basal traction and topography from surface data. Flexible generation of the adjoint for a range of independent uncertain variables is exemplified through sensitivity calculations of grounded ice volume to changes in basal melting of floating and basal sliding of grounded ice. The results are encouraging and suggest the feasibility, using real observations, of improved ice sheet state estimation and comprehensive transient sensitivity assessments. |
format |
Article in Journal/Newspaper |
author |
D. N. Goldberg P. Heimbach |
author_facet |
D. N. Goldberg P. Heimbach |
author_sort |
D. N. Goldberg |
title |
Parameter and state estimation with a time-dependent adjoint marine ice sheet model |
title_short |
Parameter and state estimation with a time-dependent adjoint marine ice sheet model |
title_full |
Parameter and state estimation with a time-dependent adjoint marine ice sheet model |
title_fullStr |
Parameter and state estimation with a time-dependent adjoint marine ice sheet model |
title_full_unstemmed |
Parameter and state estimation with a time-dependent adjoint marine ice sheet model |
title_sort |
parameter and state estimation with a time-dependent adjoint marine ice sheet model |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/tc-7-1659-2013 https://doaj.org/article/bddcb24761e94074a5b03aae1380441c |
genre |
Ice Sheet The Cryosphere |
genre_facet |
Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 7, Iss 6, Pp 1659-1678 (2013) |
op_relation |
http://www.the-cryosphere.net/7/1659/2013/tc-7-1659-2013.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-7-1659-2013 https://doaj.org/article/bddcb24761e94074a5b03aae1380441c |
op_doi |
https://doi.org/10.5194/tc-7-1659-2013 |
container_title |
The Cryosphere |
container_volume |
7 |
container_issue |
6 |
container_start_page |
1659 |
op_container_end_page |
1678 |
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1766030755398418432 |