Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow
Due to increasing surface melting on the Greenland ice sheet, better constraints on seasonally evolving basal water pressure and sliding speed are required by models. Here we assess the potential of using inverse methods on a dense time series of surface speeds to recover the seasonal evolution of t...
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ftdoajarticles:oai:doaj.org/article:1eab96279832416db1eaac802a0590b9 2023-05-15T16:27:22+02:00 Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow A. Derkacheva F. Gillet-Chaulet J. Mouginot E. Jager N. Maier S. Cook 2021-12-01T00:00:00Z https://doi.org/10.5194/tc-15-5675-2021 https://doaj.org/article/1eab96279832416db1eaac802a0590b9 EN eng Copernicus Publications https://tc.copernicus.org/articles/15/5675/2021/tc-15-5675-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-5675-2021 1994-0416 1994-0424 https://doaj.org/article/1eab96279832416db1eaac802a0590b9 The Cryosphere, Vol 15, Pp 5675-5704 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-5675-2021 2022-12-31T14:32:25Z Due to increasing surface melting on the Greenland ice sheet, better constraints on seasonally evolving basal water pressure and sliding speed are required by models. Here we assess the potential of using inverse methods on a dense time series of surface speeds to recover the seasonal evolution of the basal conditions in a well-documented region in southwest Greenland. Using data compiled from multiple satellite missions, we document seasonally evolving surface velocities with a temporal resolution of 2 weeks between 2015 and 2019. We then apply the inverse control method using the ice flow model Elmer/Ice to infer the basal sliding and friction corresponding to each of the 24 surface velocity data sets. Near the margin where the uncertainty in the velocity and bed topography are small, we obtain clear seasonal variations that can be mostly interpreted in terms of an effective-pressure-based hard-bed friction law. We find for valley bottoms or “troughs” in the bed topography that the changes in modelled basal conditions directly respond to local modelled water pressure variations, while the link is more complex for subglacial “ridges” which are often non-locally forced. At the catchment scale, in-phase variations in the water pressure, surface velocities, and surface runoff variations are found. Our results show that time series inversions of observed surface velocities can be used to understand the evolution of basal conditions over different timescales and could therefore serve as an intermediate validation for subglacial hydrology models to achieve better coupling with ice flow models. Article in Journal/Newspaper Greenland Ice Sheet The Cryosphere Directory of Open Access Journals: DOAJ Articles Greenland The Cryosphere 15 12 5675 5704 |
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 A. Derkacheva F. Gillet-Chaulet J. Mouginot E. Jager N. Maier S. Cook Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Due to increasing surface melting on the Greenland ice sheet, better constraints on seasonally evolving basal water pressure and sliding speed are required by models. Here we assess the potential of using inverse methods on a dense time series of surface speeds to recover the seasonal evolution of the basal conditions in a well-documented region in southwest Greenland. Using data compiled from multiple satellite missions, we document seasonally evolving surface velocities with a temporal resolution of 2 weeks between 2015 and 2019. We then apply the inverse control method using the ice flow model Elmer/Ice to infer the basal sliding and friction corresponding to each of the 24 surface velocity data sets. Near the margin where the uncertainty in the velocity and bed topography are small, we obtain clear seasonal variations that can be mostly interpreted in terms of an effective-pressure-based hard-bed friction law. We find for valley bottoms or “troughs” in the bed topography that the changes in modelled basal conditions directly respond to local modelled water pressure variations, while the link is more complex for subglacial “ridges” which are often non-locally forced. At the catchment scale, in-phase variations in the water pressure, surface velocities, and surface runoff variations are found. Our results show that time series inversions of observed surface velocities can be used to understand the evolution of basal conditions over different timescales and could therefore serve as an intermediate validation for subglacial hydrology models to achieve better coupling with ice flow models. |
format |
Article in Journal/Newspaper |
author |
A. Derkacheva F. Gillet-Chaulet J. Mouginot E. Jager N. Maier S. Cook |
author_facet |
A. Derkacheva F. Gillet-Chaulet J. Mouginot E. Jager N. Maier S. Cook |
author_sort |
A. Derkacheva |
title |
Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow |
title_short |
Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow |
title_full |
Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow |
title_fullStr |
Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow |
title_full_unstemmed |
Seasonal evolution of basal environment conditions of Russell sector, West Greenland, inverted from satellite observation of surface flow |
title_sort |
seasonal evolution of basal environment conditions of russell sector, west greenland, inverted from satellite observation of surface flow |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-5675-2021 https://doaj.org/article/1eab96279832416db1eaac802a0590b9 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet The Cryosphere |
genre_facet |
Greenland Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 5675-5704 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/5675/2021/tc-15-5675-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-5675-2021 1994-0416 1994-0424 https://doaj.org/article/1eab96279832416db1eaac802a0590b9 |
op_doi |
https://doi.org/10.5194/tc-15-5675-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
12 |
container_start_page |
5675 |
op_container_end_page |
5704 |
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1766016519173570560 |