On the limit to resolution and information on basal properties obtainable from surface data on ice streams
An optimal estimation method for simultaneously determining both basal slipperiness and basal topography from variations in surface flow velocity and topography along a flow line on ice streams and ice sheets is presented. We use Bayesian inference to update prior statistical estimates for basal top...
Published in: | The Cryosphere |
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Language: | English |
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Copernicus Publications
2008
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00030848 2023-05-15T18:32:32+02:00 On the limit to resolution and information on basal properties obtainable from surface data on ice streams Gudmundsson, G. H. Raymond, M. 2008-12 electronic https://doi.org/10.5194/tc-2-167-2008 https://noa.gwlb.de/receive/cop_mods_00030848 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00030802/tc-2-167-2008.pdf https://tc.copernicus.org/articles/2/167/2008/tc-2-167-2008.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-2-167-2008 https://noa.gwlb.de/receive/cop_mods_00030848 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00030802/tc-2-167-2008.pdf https://tc.copernicus.org/articles/2/167/2008/tc-2-167-2008.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2008 ftnonlinearchiv https://doi.org/10.5194/tc-2-167-2008 2022-02-08T22:47:01Z An optimal estimation method for simultaneously determining both basal slipperiness and basal topography from variations in surface flow velocity and topography along a flow line on ice streams and ice sheets is presented. We use Bayesian inference to update prior statistical estimates for basal topography and slipperiness using surface measurements along a flow line. Our main focus here is on how errors and spacing of surface data affect estimates of basal quantities and on possibly aliasing/mixing between basal slipperiness and basal topography. We find that the effects of spatial variations in basal topography and basal slipperiness on surface data can be accurately separated from each other, and mixing in retrieval does not pose a serious problem. For realistic surface data errors and density, small-amplitude perturbations in basal slipperiness can only be resolved for wavelengths larger than about 50 times the mean ice thickness. Bedrock topography is well resolved down to horizontal scale equal to about one ice thickness. Estimates of basal slipperiness are not significantly improved by accurate prior estimates of basal topography. However, retrieval of basal slipperiness is found to be highly sensitive to unmodelled errors in basal topography. Article in Journal/Newspaper The Cryosphere Niedersächsisches Online-Archiv NOA The Cryosphere 2 2 167 178 |
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English |
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article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Gudmundsson, G. H. Raymond, M. On the limit to resolution and information on basal properties obtainable from surface data on ice streams |
topic_facet |
article Verlagsveröffentlichung |
description |
An optimal estimation method for simultaneously determining both basal slipperiness and basal topography from variations in surface flow velocity and topography along a flow line on ice streams and ice sheets is presented. We use Bayesian inference to update prior statistical estimates for basal topography and slipperiness using surface measurements along a flow line. Our main focus here is on how errors and spacing of surface data affect estimates of basal quantities and on possibly aliasing/mixing between basal slipperiness and basal topography. We find that the effects of spatial variations in basal topography and basal slipperiness on surface data can be accurately separated from each other, and mixing in retrieval does not pose a serious problem. For realistic surface data errors and density, small-amplitude perturbations in basal slipperiness can only be resolved for wavelengths larger than about 50 times the mean ice thickness. Bedrock topography is well resolved down to horizontal scale equal to about one ice thickness. Estimates of basal slipperiness are not significantly improved by accurate prior estimates of basal topography. However, retrieval of basal slipperiness is found to be highly sensitive to unmodelled errors in basal topography. |
format |
Article in Journal/Newspaper |
author |
Gudmundsson, G. H. Raymond, M. |
author_facet |
Gudmundsson, G. H. Raymond, M. |
author_sort |
Gudmundsson, G. H. |
title |
On the limit to resolution and information on basal properties obtainable from surface data on ice streams |
title_short |
On the limit to resolution and information on basal properties obtainable from surface data on ice streams |
title_full |
On the limit to resolution and information on basal properties obtainable from surface data on ice streams |
title_fullStr |
On the limit to resolution and information on basal properties obtainable from surface data on ice streams |
title_full_unstemmed |
On the limit to resolution and information on basal properties obtainable from surface data on ice streams |
title_sort |
on the limit to resolution and information on basal properties obtainable from surface data on ice streams |
publisher |
Copernicus Publications |
publishDate |
2008 |
url |
https://doi.org/10.5194/tc-2-167-2008 https://noa.gwlb.de/receive/cop_mods_00030848 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00030802/tc-2-167-2008.pdf https://tc.copernicus.org/articles/2/167/2008/tc-2-167-2008.pdf |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-2-167-2008 https://noa.gwlb.de/receive/cop_mods_00030848 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00030802/tc-2-167-2008.pdf https://tc.copernicus.org/articles/2/167/2008/tc-2-167-2008.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-2-167-2008 |
container_title |
The Cryosphere |
container_volume |
2 |
container_issue |
2 |
container_start_page |
167 |
op_container_end_page |
178 |
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1766216663464673280 |