Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting
Modeling the physical state of permafrost landscapes is a crucial addition to field observations in order to understand the feedback mechanisms between permafrost and the atmosphere within a warming climate. A common hypothesis in permafrost modeling is that vertical heat conduction is most relevant...
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Copernicus Publications
2021
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Online Access: | https://doi.org/10.5194/tc-15-4853-2021 https://tc.copernicus.org/articles/15/4853/2021/tc-15-4853-2021.pdf https://doaj.org/article/a427a4fbbd58408b83fcd131b7e34454 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:a427a4fbbd58408b83fcd131b7e34454 2023-05-15T13:05:47+02:00 Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting A. Hamm A. Frampton 2021-10-01 https://doi.org/10.5194/tc-15-4853-2021 https://tc.copernicus.org/articles/15/4853/2021/tc-15-4853-2021.pdf https://doaj.org/article/a427a4fbbd58408b83fcd131b7e34454 en eng Copernicus Publications doi:10.5194/tc-15-4853-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/4853/2021/tc-15-4853-2021.pdf https://doaj.org/article/a427a4fbbd58408b83fcd131b7e34454 undefined The Cryosphere, Vol 15, Pp 4853-4871 (2021) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2021 fttriple https://doi.org/10.5194/tc-15-4853-2021 2023-01-22T17:52:25Z Modeling the physical state of permafrost landscapes is a crucial addition to field observations in order to understand the feedback mechanisms between permafrost and the atmosphere within a warming climate. A common hypothesis in permafrost modeling is that vertical heat conduction is most relevant to derive subsurface temperatures. While this approach is mostly applicable to flat landscapes with little topography, landscapes with more topography are subject to lateral flow processes as well. With our study, we contribute to the growing body of evidence that lateral surface and subsurface processes can have a significant impact on permafrost temperatures and active layer properties. We use a numerical model to simulate two idealized hillslopes (a steep and a medium case) with inclinations that can be found in Adventdalen, Svalbard, and compare them to a flat control case. We find that ground temperatures within the active layer uphill are generally warmer than downhill in both slopes (with a difference of up to ∼0.8 ∘C in the steep and ∼0.6 ∘C in the medium slope). Further, the slopes are found to be warmer in the uphill section and colder in the base of the slopes compared to the flat control case. As a result, maximum thaw depth increases by about 5 cm from the flat (0.98 m) to the medium (1.03 m) and the steep slope (1.03 m). Uphill warming on the slopes is explained by overall lower heat capacity, additional energy gain through infiltration, and lower evaporation rates due to drier conditions caused by subsurface runoff. The major governing process causing the cooling on the downslope side is heat loss to the atmosphere through evaporation in summer and enhanced heat loss in winter due to wetter conditions and resulting increased thermal conductivity. On a catchment scale, these results suggest that temperature distributions in sloped terrain can vary considerably compared to flat terrain, which might impact the response of subsurface hydrothermal conditions to ongoing climate change. Article in Journal/Newspaper Adventdalen Arctic Climate change permafrost Svalbard The Cryosphere Unknown Adventdalen ENVELOPE(16.264,16.264,78.181,78.181) Arctic Svalbard The Cryosphere 15 10 4853 4871 |
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Open Polar |
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English |
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geo envir |
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geo envir A. Hamm A. Frampton Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting |
topic_facet |
geo envir |
description |
Modeling the physical state of permafrost landscapes is a crucial addition to field observations in order to understand the feedback mechanisms between permafrost and the atmosphere within a warming climate. A common hypothesis in permafrost modeling is that vertical heat conduction is most relevant to derive subsurface temperatures. While this approach is mostly applicable to flat landscapes with little topography, landscapes with more topography are subject to lateral flow processes as well. With our study, we contribute to the growing body of evidence that lateral surface and subsurface processes can have a significant impact on permafrost temperatures and active layer properties. We use a numerical model to simulate two idealized hillslopes (a steep and a medium case) with inclinations that can be found in Adventdalen, Svalbard, and compare them to a flat control case. We find that ground temperatures within the active layer uphill are generally warmer than downhill in both slopes (with a difference of up to ∼0.8 ∘C in the steep and ∼0.6 ∘C in the medium slope). Further, the slopes are found to be warmer in the uphill section and colder in the base of the slopes compared to the flat control case. As a result, maximum thaw depth increases by about 5 cm from the flat (0.98 m) to the medium (1.03 m) and the steep slope (1.03 m). Uphill warming on the slopes is explained by overall lower heat capacity, additional energy gain through infiltration, and lower evaporation rates due to drier conditions caused by subsurface runoff. The major governing process causing the cooling on the downslope side is heat loss to the atmosphere through evaporation in summer and enhanced heat loss in winter due to wetter conditions and resulting increased thermal conductivity. On a catchment scale, these results suggest that temperature distributions in sloped terrain can vary considerably compared to flat terrain, which might impact the response of subsurface hydrothermal conditions to ongoing climate change. |
format |
Article in Journal/Newspaper |
author |
A. Hamm A. Frampton |
author_facet |
A. Hamm A. Frampton |
author_sort |
A. Hamm |
title |
Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting |
title_short |
Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting |
title_full |
Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting |
title_fullStr |
Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting |
title_full_unstemmed |
Impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-Arctic hillslope setting |
title_sort |
impact of lateral groundwater flow on hydrothermal conditions of the active layer in a high-arctic hillslope setting |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-4853-2021 https://tc.copernicus.org/articles/15/4853/2021/tc-15-4853-2021.pdf https://doaj.org/article/a427a4fbbd58408b83fcd131b7e34454 |
long_lat |
ENVELOPE(16.264,16.264,78.181,78.181) |
geographic |
Adventdalen Arctic Svalbard |
geographic_facet |
Adventdalen Arctic Svalbard |
genre |
Adventdalen Arctic Climate change permafrost Svalbard The Cryosphere |
genre_facet |
Adventdalen Arctic Climate change permafrost Svalbard The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 4853-4871 (2021) |
op_relation |
doi:10.5194/tc-15-4853-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/4853/2021/tc-15-4853-2021.pdf https://doaj.org/article/a427a4fbbd58408b83fcd131b7e34454 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-15-4853-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
10 |
container_start_page |
4853 |
op_container_end_page |
4871 |
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1766393736377401344 |