Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study
Determining recent Antarctic ice volume changes from satellite altimeter measurements of ice surface height requires a correction for contemporaneous vertical crustal deformation. This correction must consider two main sources of crustal deformation: (1) ongoing glacial isostatic adjustment (GIA), t...
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ftcopernicus:oai:publications.copernicus.org:tc115570 2024-09-15T17:48:36+00:00 Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study Valencic, Natasha Pan, Linda Latychev, Konstantin Gomez, Natalya Powell, Evelyn Mitrovica, Jerry X. 2024-06-26 application/pdf https://doi.org/10.5194/tc-18-2969-2024 https://tc.copernicus.org/articles/18/2969/2024/ eng eng doi:10.5194/tc-18-2969-2024 https://tc.copernicus.org/articles/18/2969/2024/ eISSN: 1994-0424 Text 2024 ftcopernicus https://doi.org/10.5194/tc-18-2969-2024 2024-08-28T05:24:22Z Determining recent Antarctic ice volume changes from satellite altimeter measurements of ice surface height requires a correction for contemporaneous vertical crustal deformation. This correction must consider two main sources of crustal deformation: (1) ongoing glacial isostatic adjustment (GIA), that is, the deformational, gravitational, and rotational response to Late Pleistocene and Holocene ice and ocean mass changes and (2) modern ice mass change. In this study, we seek to quantify the uncertainties associated with each of these corrections. Corrections of ice surface height changes for correction 1 have generally involved the adoption of global models of GIA defined by some preferred combination of ice history and mantle viscoelastic structure. We have computed the GIA correction generated from a coupled ice sheet–sea level model and a realistic Earth model incorporating three-dimensional viscoelastic structure. Integrating the difference between this correction and those from recent GIA analyses widely adopted in the literature yields an uncertainty in total present-day ice volume change equivalent to approximately 10 % of Antarctic ice mass loss inferred for the period 2010–2020. This reinforces earlier work indicating that ice histories characterized by relatively high excess ice volume at the Last Glacial Maximum may be introducing a significant error in estimates of modern melt rates. Regarding correction 2, a spatially invariant scaling has commonly been used to convert GIA-corrected ice surface height changes obtained from satellite altimetry to ice volume estimates. We adopt modeling results based on a projection of Antarctic ice mass change over the period 2015–2055 to demonstrate a spatial variability in the scaling of up to 10 % across the ice sheet. Furthermore, using these calculations, we find a systematic error of ∼ 3 % in the projected net ice volume change, with most of the difference arising in areas of West Antarctica above mantle zones of low viscosity. Text Antarc* Antarctic Antarctica Ice Sheet West Antarctica Copernicus Publications: E-Journals The Cryosphere 18 6 2969 2978 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Determining recent Antarctic ice volume changes from satellite altimeter measurements of ice surface height requires a correction for contemporaneous vertical crustal deformation. This correction must consider two main sources of crustal deformation: (1) ongoing glacial isostatic adjustment (GIA), that is, the deformational, gravitational, and rotational response to Late Pleistocene and Holocene ice and ocean mass changes and (2) modern ice mass change. In this study, we seek to quantify the uncertainties associated with each of these corrections. Corrections of ice surface height changes for correction 1 have generally involved the adoption of global models of GIA defined by some preferred combination of ice history and mantle viscoelastic structure. We have computed the GIA correction generated from a coupled ice sheet–sea level model and a realistic Earth model incorporating three-dimensional viscoelastic structure. Integrating the difference between this correction and those from recent GIA analyses widely adopted in the literature yields an uncertainty in total present-day ice volume change equivalent to approximately 10 % of Antarctic ice mass loss inferred for the period 2010–2020. This reinforces earlier work indicating that ice histories characterized by relatively high excess ice volume at the Last Glacial Maximum may be introducing a significant error in estimates of modern melt rates. Regarding correction 2, a spatially invariant scaling has commonly been used to convert GIA-corrected ice surface height changes obtained from satellite altimetry to ice volume estimates. We adopt modeling results based on a projection of Antarctic ice mass change over the period 2015–2055 to demonstrate a spatial variability in the scaling of up to 10 % across the ice sheet. Furthermore, using these calculations, we find a systematic error of ∼ 3 % in the projected net ice volume change, with most of the difference arising in areas of West Antarctica above mantle zones of low viscosity. |
format |
Text |
author |
Valencic, Natasha Pan, Linda Latychev, Konstantin Gomez, Natalya Powell, Evelyn Mitrovica, Jerry X. |
spellingShingle |
Valencic, Natasha Pan, Linda Latychev, Konstantin Gomez, Natalya Powell, Evelyn Mitrovica, Jerry X. Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study |
author_facet |
Valencic, Natasha Pan, Linda Latychev, Konstantin Gomez, Natalya Powell, Evelyn Mitrovica, Jerry X. |
author_sort |
Valencic, Natasha |
title |
Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study |
title_short |
Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study |
title_full |
Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study |
title_fullStr |
Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study |
title_full_unstemmed |
Mapping geodetically inferred Antarctic ice surface height changes into thickness changes: a sensitivity study |
title_sort |
mapping geodetically inferred antarctic ice surface height changes into thickness changes: a sensitivity study |
publishDate |
2024 |
url |
https://doi.org/10.5194/tc-18-2969-2024 https://tc.copernicus.org/articles/18/2969/2024/ |
genre |
Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet West Antarctica |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-18-2969-2024 https://tc.copernicus.org/articles/18/2969/2024/ |
op_doi |
https://doi.org/10.5194/tc-18-2969-2024 |
container_title |
The Cryosphere |
container_volume |
18 |
container_issue |
6 |
container_start_page |
2969 |
op_container_end_page |
2978 |
_version_ |
1810290034664800256 |