Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models
Permafrost degradation within a warming climate poses a significant environmental threat through both the permafrost carbon feedback and damage to human communities and infrastructure. Understanding this threat relies on better understanding and numerical representation of thermo-hydrological permaf...
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ftdoajarticles:oai:doaj.org/article:896430fb379f455e93bc3942df711343 2023-05-15T15:16:47+02:00 Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models B. Gao E. T. Coon 2022-10-01T00:00:00Z https://doi.org/10.5194/tc-16-4141-2022 https://doaj.org/article/896430fb379f455e93bc3942df711343 EN eng Copernicus Publications https://tc.copernicus.org/articles/16/4141/2022/tc-16-4141-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4141-2022 1994-0416 1994-0424 https://doaj.org/article/896430fb379f455e93bc3942df711343 The Cryosphere, Vol 16, Pp 4141-4162 (2022) Environmental sciences GE1-350 Geology QE1-996.5 article 2022 ftdoajarticles https://doi.org/10.5194/tc-16-4141-2022 2022-12-30T20:52:29Z Permafrost degradation within a warming climate poses a significant environmental threat through both the permafrost carbon feedback and damage to human communities and infrastructure. Understanding this threat relies on better understanding and numerical representation of thermo-hydrological permafrost processes and the subsequent accurate prediction of permafrost dynamics. All models include simplified assumptions, implying a tradeoff between model complexity and prediction accuracy. The main purpose of this work is to investigate this tradeoff when applying the following commonly made assumptions: (1) assuming equal density of ice and liquid water in frozen soil, (2) neglecting the effect of cryosuction in unsaturated freezing soil, and (3) neglecting advective heat transport during soil freezing and thaw. This study designed a set of 62 numerical experiments using the Advanced Terrestrial Simulator (ATS v1.2) to evaluate the effects of these choices on permafrost hydrological outputs, including both integrated and pointwise quantities. Simulations were conducted under different climate conditions and soil properties from three different sites in both column- and hillslope-scale configurations. Results showed that amongst the three physical assumptions, soil cryosuction is the most crucial yet commonly ignored process. Neglecting cryosuction, on average, can cause 10 %–20 % error in predicting evaporation, 50 %–60 % error in discharge, 10 %–30 % error in thaw depth, and 10 %–30 % error in soil temperature at 1 m beneath the surface. The prediction error for subsurface temperature and water saturation is more obvious at hillslope scales due to the presence of lateral flux. By comparison, using equal ice–liquid density has a minor impact on most hydrological metrics of interest but significantly affects soil water saturation with an averaged 5 %–15 % error. Neglecting advective heat transport presents the least error, 5 % or even much lower, in most metrics of interest for a large-scale Arctic tundra system ... Article in Journal/Newspaper Arctic Ice permafrost The Cryosphere Tundra Directory of Open Access Journals: DOAJ Articles Arctic The Cryosphere 16 10 4141 4162 |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
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Environmental sciences GE1-350 Geology QE1-996.5 B. Gao E. T. Coon Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Permafrost degradation within a warming climate poses a significant environmental threat through both the permafrost carbon feedback and damage to human communities and infrastructure. Understanding this threat relies on better understanding and numerical representation of thermo-hydrological permafrost processes and the subsequent accurate prediction of permafrost dynamics. All models include simplified assumptions, implying a tradeoff between model complexity and prediction accuracy. The main purpose of this work is to investigate this tradeoff when applying the following commonly made assumptions: (1) assuming equal density of ice and liquid water in frozen soil, (2) neglecting the effect of cryosuction in unsaturated freezing soil, and (3) neglecting advective heat transport during soil freezing and thaw. This study designed a set of 62 numerical experiments using the Advanced Terrestrial Simulator (ATS v1.2) to evaluate the effects of these choices on permafrost hydrological outputs, including both integrated and pointwise quantities. Simulations were conducted under different climate conditions and soil properties from three different sites in both column- and hillslope-scale configurations. Results showed that amongst the three physical assumptions, soil cryosuction is the most crucial yet commonly ignored process. Neglecting cryosuction, on average, can cause 10 %–20 % error in predicting evaporation, 50 %–60 % error in discharge, 10 %–30 % error in thaw depth, and 10 %–30 % error in soil temperature at 1 m beneath the surface. The prediction error for subsurface temperature and water saturation is more obvious at hillslope scales due to the presence of lateral flux. By comparison, using equal ice–liquid density has a minor impact on most hydrological metrics of interest but significantly affects soil water saturation with an averaged 5 %–15 % error. Neglecting advective heat transport presents the least error, 5 % or even much lower, in most metrics of interest for a large-scale Arctic tundra system ... |
format |
Article in Journal/Newspaper |
author |
B. Gao E. T. Coon |
author_facet |
B. Gao E. T. Coon |
author_sort |
B. Gao |
title |
Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models |
title_short |
Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models |
title_full |
Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models |
title_fullStr |
Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models |
title_full_unstemmed |
Evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models |
title_sort |
evaluating simplifications of subsurface process representations for field-scale permafrost hydrology models |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/tc-16-4141-2022 https://doaj.org/article/896430fb379f455e93bc3942df711343 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Ice permafrost The Cryosphere Tundra |
genre_facet |
Arctic Ice permafrost The Cryosphere Tundra |
op_source |
The Cryosphere, Vol 16, Pp 4141-4162 (2022) |
op_relation |
https://tc.copernicus.org/articles/16/4141/2022/tc-16-4141-2022.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-16-4141-2022 1994-0416 1994-0424 https://doaj.org/article/896430fb379f455e93bc3942df711343 |
op_doi |
https://doi.org/10.5194/tc-16-4141-2022 |
container_title |
The Cryosphere |
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16 |
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10 |
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4141 |
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4162 |
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