Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model
Understanding the stress-dependent behaviour of the ice sheet is critical to projecting ice mass balance. Glen's law is used to calculate ice viscosity, conventionally with a stress exponent (n) equal to three. However, a stress exponent of four has recently been proposed for ice dynamics. The...
Main Authors: | , , |
---|---|
Format: | Text |
Language: | English |
Published: |
2024
|
Subjects: | |
Online Access: | https://doi.org/10.5194/egusphere-2023-2987 https://egusphere.copernicus.org/preprints/2024/egusphere-2023-2987/ |
id |
ftcopernicus:oai:publications.copernicus.org:egusphere116760 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:egusphere116760 2024-09-09T19:04:41+00:00 Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model Lim, Su-Jeong Baek, Yi-Jeong So, Byung-Dal 2024-02-08 application/pdf https://doi.org/10.5194/egusphere-2023-2987 https://egusphere.copernicus.org/preprints/2024/egusphere-2023-2987/ eng eng doi:10.5194/egusphere-2023-2987 https://egusphere.copernicus.org/preprints/2024/egusphere-2023-2987/ eISSN: Text 2024 ftcopernicus https://doi.org/10.5194/egusphere-2023-2987 2024-08-28T05:24:15Z Understanding the stress-dependent behaviour of the ice sheet is critical to projecting ice mass balance. Glen's law is used to calculate ice viscosity, conventionally with a stress exponent (n) equal to three. However, a stress exponent of four has recently been proposed for ice dynamics. The suggested range of the fluidity parameter (A) for n = 4 is of the order of six (i.e., 10 -35 to 10 -29 Pa -4 s -1 ), leading to a significant uncertainty in ice velocity than when n = 3. Here, we refined A to within one order, aligning with observed Antarctic ice velocities with simplified slope and Antarctic bed topography models. The Antarctic bed topography models, based on Antarctic BedMap2 data, specifically include the Ronne, Thwaites, and Ross Ice Shelves for West Antarctica, and the Amery, Shackleton Ice Shelves, and Mertz Glacial Tongue for East Antarctica. We found that the simplified model and the West and East Antarctic models share a common range of A values for matching observed Antarctic ice velocities. Refinement narrows the range of A to within one order for both the simplified and West/East Antarctic models. The narrowed range for A is from 4.0 × to 16.0 × Pa -4 s -1 . Both models have common A values for representing Antarctic ice velocity, providing an insight into the applicable A values. Text Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelves West Antarctica Copernicus Publications: E-Journals Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Antarctic East Antarctica Narrows The ENVELOPE(-67.167,-67.167,-67.617,-67.617) Shackleton The Antarctic West Antarctica |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Understanding the stress-dependent behaviour of the ice sheet is critical to projecting ice mass balance. Glen's law is used to calculate ice viscosity, conventionally with a stress exponent (n) equal to three. However, a stress exponent of four has recently been proposed for ice dynamics. The suggested range of the fluidity parameter (A) for n = 4 is of the order of six (i.e., 10 -35 to 10 -29 Pa -4 s -1 ), leading to a significant uncertainty in ice velocity than when n = 3. Here, we refined A to within one order, aligning with observed Antarctic ice velocities with simplified slope and Antarctic bed topography models. The Antarctic bed topography models, based on Antarctic BedMap2 data, specifically include the Ronne, Thwaites, and Ross Ice Shelves for West Antarctica, and the Amery, Shackleton Ice Shelves, and Mertz Glacial Tongue for East Antarctica. We found that the simplified model and the West and East Antarctic models share a common range of A values for matching observed Antarctic ice velocities. Refinement narrows the range of A to within one order for both the simplified and West/East Antarctic models. The narrowed range for A is from 4.0 × to 16.0 × Pa -4 s -1 . Both models have common A values for representing Antarctic ice velocity, providing an insight into the applicable A values. |
format |
Text |
author |
Lim, Su-Jeong Baek, Yi-Jeong So, Byung-Dal |
spellingShingle |
Lim, Su-Jeong Baek, Yi-Jeong So, Byung-Dal Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model |
author_facet |
Lim, Su-Jeong Baek, Yi-Jeong So, Byung-Dal |
author_sort |
Lim, Su-Jeong |
title |
Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model |
title_short |
Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model |
title_full |
Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model |
title_fullStr |
Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model |
title_full_unstemmed |
Refinement of the fluidity parameter range with a stress exponent of four in Glen’s law: insights from Antarctic bed topography model |
title_sort |
refinement of the fluidity parameter range with a stress exponent of four in glen’s law: insights from antarctic bed topography model |
publishDate |
2024 |
url |
https://doi.org/10.5194/egusphere-2023-2987 https://egusphere.copernicus.org/preprints/2024/egusphere-2023-2987/ |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(-67.167,-67.167,-67.617,-67.617) |
geographic |
Amery Antarctic East Antarctica Narrows The Shackleton The Antarctic West Antarctica |
geographic_facet |
Amery Antarctic East Antarctica Narrows The Shackleton The Antarctic West Antarctica |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelves West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Ice Shelves West Antarctica |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2023-2987 https://egusphere.copernicus.org/preprints/2024/egusphere-2023-2987/ |
op_doi |
https://doi.org/10.5194/egusphere-2023-2987 |
_version_ |
1809818724312547328 |