Grain growth of natural and synthetic ice at 0 °C
Grain growth can modify the microstructure of natural ice, including the grain size and crystallographic preferred orientation (CPO). To better understand grain-growth processes and kinetics, we compared microstructural data from synthetic and natural ice samples of similar starting grain sizes that...
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ftcopernicus:oai:publications.copernicus.org:tc107935 2023-09-26T15:11:50+02:00 Grain growth of natural and synthetic ice at 0 °C Fan, Sheng Prior, David J. Pooley, Brent Bowman, Hamish Davidson, Lucy Wallis, David Piazolo, Sandra Qi, Chao Goldsby, David L. Hager, Travis F. 2023-08-23 application/pdf https://doi.org/10.5194/tc-17-3443-2023 https://tc.copernicus.org/articles/17/3443/2023/ eng eng doi:10.5194/tc-17-3443-2023 https://tc.copernicus.org/articles/17/3443/2023/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-17-3443-2023 2023-08-28T16:24:15Z Grain growth can modify the microstructure of natural ice, including the grain size and crystallographic preferred orientation (CPO). To better understand grain-growth processes and kinetics, we compared microstructural data from synthetic and natural ice samples of similar starting grain sizes that were annealed at the solidus temperature (0 ∘ C) for durations of a few hours to 33 d. The synthetic ice has a homogeneous initial microstructure characterized by polygonal grains, little intragranular distortion, few bubbles, and a near-random CPO. The natural ice samples were subsampled from ice cores acquired from the Priestley Glacier, Antarctica. This natural ice has a heterogeneous microstructure characterized by a considerable number of air bubbles, widespread intragranular distortion, and a CPO. During annealing, the average grain size of the natural ice barely changes, whereas the average grain size of the synthetic ice gradually increases. These observations demonstrate that grain growth in natural ice can be much slower than in synthetic ice and therefore that the grain-growth law derived from synthetic ice cannot be directly applied to estimate the grain-size evolution in natural ice with a different microstructure. The microstructure of natural ice is characterized by many bubbles that pin grain boundaries. Previous studies suggest that bubble pinning provides a resisting force that reduces the effective driving force of grain-boundary migration and is therefore linked to the inhibition of grain growth observed in natural ice. As annealing progresses, the number density (number per unit area) of bubbles on grain boundaries in the natural ice decreases, whilst the number density of bubbles in the grain interiors increases. This observation indicates that some grain boundaries sweep through bubbles, which should weaken the pinning effect and thus reduce the resisting force for grain-boundary migration. Some of the Priestley ice grains become abnormally large during annealing. We speculate that the contrast ... Text Antarc* Antarctica Priestley Glacier Copernicus Publications: E-Journals Priestley ENVELOPE(161.883,161.883,-75.183,-75.183) Priestley Glacier ENVELOPE(163.367,163.367,-74.333,-74.333) The Cryosphere 17 8 3443 3459 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Grain growth can modify the microstructure of natural ice, including the grain size and crystallographic preferred orientation (CPO). To better understand grain-growth processes and kinetics, we compared microstructural data from synthetic and natural ice samples of similar starting grain sizes that were annealed at the solidus temperature (0 ∘ C) for durations of a few hours to 33 d. The synthetic ice has a homogeneous initial microstructure characterized by polygonal grains, little intragranular distortion, few bubbles, and a near-random CPO. The natural ice samples were subsampled from ice cores acquired from the Priestley Glacier, Antarctica. This natural ice has a heterogeneous microstructure characterized by a considerable number of air bubbles, widespread intragranular distortion, and a CPO. During annealing, the average grain size of the natural ice barely changes, whereas the average grain size of the synthetic ice gradually increases. These observations demonstrate that grain growth in natural ice can be much slower than in synthetic ice and therefore that the grain-growth law derived from synthetic ice cannot be directly applied to estimate the grain-size evolution in natural ice with a different microstructure. The microstructure of natural ice is characterized by many bubbles that pin grain boundaries. Previous studies suggest that bubble pinning provides a resisting force that reduces the effective driving force of grain-boundary migration and is therefore linked to the inhibition of grain growth observed in natural ice. As annealing progresses, the number density (number per unit area) of bubbles on grain boundaries in the natural ice decreases, whilst the number density of bubbles in the grain interiors increases. This observation indicates that some grain boundaries sweep through bubbles, which should weaken the pinning effect and thus reduce the resisting force for grain-boundary migration. Some of the Priestley ice grains become abnormally large during annealing. We speculate that the contrast ... |
format |
Text |
author |
Fan, Sheng Prior, David J. Pooley, Brent Bowman, Hamish Davidson, Lucy Wallis, David Piazolo, Sandra Qi, Chao Goldsby, David L. Hager, Travis F. |
spellingShingle |
Fan, Sheng Prior, David J. Pooley, Brent Bowman, Hamish Davidson, Lucy Wallis, David Piazolo, Sandra Qi, Chao Goldsby, David L. Hager, Travis F. Grain growth of natural and synthetic ice at 0 °C |
author_facet |
Fan, Sheng Prior, David J. Pooley, Brent Bowman, Hamish Davidson, Lucy Wallis, David Piazolo, Sandra Qi, Chao Goldsby, David L. Hager, Travis F. |
author_sort |
Fan, Sheng |
title |
Grain growth of natural and synthetic ice at 0 °C |
title_short |
Grain growth of natural and synthetic ice at 0 °C |
title_full |
Grain growth of natural and synthetic ice at 0 °C |
title_fullStr |
Grain growth of natural and synthetic ice at 0 °C |
title_full_unstemmed |
Grain growth of natural and synthetic ice at 0 °C |
title_sort |
grain growth of natural and synthetic ice at 0 °c |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-3443-2023 https://tc.copernicus.org/articles/17/3443/2023/ |
long_lat |
ENVELOPE(161.883,161.883,-75.183,-75.183) ENVELOPE(163.367,163.367,-74.333,-74.333) |
geographic |
Priestley Priestley Glacier |
geographic_facet |
Priestley Priestley Glacier |
genre |
Antarc* Antarctica Priestley Glacier |
genre_facet |
Antarc* Antarctica Priestley Glacier |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-17-3443-2023 https://tc.copernicus.org/articles/17/3443/2023/ |
op_doi |
https://doi.org/10.5194/tc-17-3443-2023 |
container_title |
The Cryosphere |
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17 |
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8 |
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3443 |
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3459 |
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1778132261026136064 |