Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data
We propose a new approach to indirectly estimate basal properties of ice streams, i.e. bedrock topography and basal slipperiness, from observations of surface topography and surface velocities. We demonstrate how a maximum a posteriori estimate of basal conditions can be determined using a Bayesian...
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fttriple:oai:gotriple.eu:oai:doaj.org/article:d0b71c0cc8214e33a4855ae6f0cb807f 2023-05-15T18:32:14+02:00 Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data M. J. Raymond G. H. Gudmundsson 2009-12-01 http://www.the-cryosphere.net/3/265/2009/tc-3-265-2009.pdf https://doaj.org/article/d0b71c0cc8214e33a4855ae6f0cb807f en eng Copernicus Publications 1994-0416 1994-0424 http://www.the-cryosphere.net/3/265/2009/tc-3-265-2009.pdf https://doaj.org/article/d0b71c0cc8214e33a4855ae6f0cb807f undefined The Cryosphere, Vol 3, Iss 2, Pp 265-278 (2009) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2009 fttriple 2023-01-22T19:15:31Z We propose a new approach to indirectly estimate basal properties of ice streams, i.e. bedrock topography and basal slipperiness, from observations of surface topography and surface velocities. We demonstrate how a maximum a posteriori estimate of basal conditions can be determined using a Bayesian inference approach in a combination with an analytical linearisation of the forward model. Using synthetic data we show that for non-linear media and non-linear sliding law only a few forward-step model evaluations are needed for convergence. The forward step is solved with a numerical finite-element model using the full Stokes equations. The Fréchet derivative of the forward function is approximated through analytical small-perturbation solutions. This approximation is a key feature of the method and the effects of this approximation on model performance are analyzed. The number of iterations needed for convergence increases with the amplitude of the basal perturbations, but generally less than ten iterations are needed. Article in Journal/Newspaper The Cryosphere Unknown |
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geo envir M. J. Raymond G. H. Gudmundsson Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data |
topic_facet |
geo envir |
description |
We propose a new approach to indirectly estimate basal properties of ice streams, i.e. bedrock topography and basal slipperiness, from observations of surface topography and surface velocities. We demonstrate how a maximum a posteriori estimate of basal conditions can be determined using a Bayesian inference approach in a combination with an analytical linearisation of the forward model. Using synthetic data we show that for non-linear media and non-linear sliding law only a few forward-step model evaluations are needed for convergence. The forward step is solved with a numerical finite-element model using the full Stokes equations. The Fréchet derivative of the forward function is approximated through analytical small-perturbation solutions. This approximation is a key feature of the method and the effects of this approximation on model performance are analyzed. The number of iterations needed for convergence increases with the amplitude of the basal perturbations, but generally less than ten iterations are needed. |
format |
Article in Journal/Newspaper |
author |
M. J. Raymond G. H. Gudmundsson |
author_facet |
M. J. Raymond G. H. Gudmundsson |
author_sort |
M. J. Raymond |
title |
Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data |
title_short |
Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data |
title_full |
Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data |
title_fullStr |
Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data |
title_full_unstemmed |
Estimating basal properties of ice streams from surface measurements: a non-linear Bayesian inverse approach applied to synthetic data |
title_sort |
estimating basal properties of ice streams from surface measurements: a non-linear bayesian inverse approach applied to synthetic data |
publisher |
Copernicus Publications |
publishDate |
2009 |
url |
http://www.the-cryosphere.net/3/265/2009/tc-3-265-2009.pdf https://doaj.org/article/d0b71c0cc8214e33a4855ae6f0cb807f |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 3, Iss 2, Pp 265-278 (2009) |
op_relation |
1994-0416 1994-0424 http://www.the-cryosphere.net/3/265/2009/tc-3-265-2009.pdf https://doaj.org/article/d0b71c0cc8214e33a4855ae6f0cb807f |
op_rights |
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_version_ |
1766216310268624896 |