Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope
ABSTRACT We extend a numerical modeling approach developed to explicitly model convective heat transfer in periglacial landforms to represent the ground thermal regime of low‐altitude talus slopes. Our model solves for heat conduction and accounts explicitly for air convection adopting a Darcy term...
Published in: | Permafrost and Periglacial Processes |
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Online Access: | http://dx.doi.org/10.1002/ppp.2224 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2224 |
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crwiley:10.1002/ppp.2224 2024-06-02T08:08:01+00:00 Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope Wicky, Jonas Hilbich, Christin Delaloye, Reynald Hauck, Christian Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung 2024 http://dx.doi.org/10.1002/ppp.2224 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2224 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Permafrost and Periglacial Processes volume 35, issue 2, page 202-217 ISSN 1045-6740 1099-1530 journal-article 2024 crwiley https://doi.org/10.1002/ppp.2224 2024-05-03T11:06:17Z ABSTRACT We extend a numerical modeling approach developed to explicitly model convective heat transfer in periglacial landforms to represent the ground thermal regime of low‐altitude talus slopes. Our model solves for heat conduction and accounts explicitly for air convection adopting a Darcy term with a Boussinesq approximation for air circulation in the porous ground. Numerical model experiments for the low‐altitude talus slope Dreveneuse, Switzerland, confirm that air convection is the key to forming and maintaining ground ice. In the model, the porous talus slope is underlain by a layer of water‐bearing morainic material. In years, where the gradient between air and talus temperature is sufficiently large to result in increased convection and therefore cooling, ground ice forms due to air convection within the porous material and lasts for more than a year. It is only by considering convection that the model is able to represent the occurrences of ground ice, in accordance with temperature observations on‐site. These findings are important, as they confirm that ground ice can be formed and maintained in landforms with a mean annual air temperature > 0°C if ground air convection is present combined with the presence of water. Article in Journal/Newspaper Ice permafrost Permafrost and Periglacial Processes Wiley Online Library Permafrost and Periglacial Processes |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
ABSTRACT We extend a numerical modeling approach developed to explicitly model convective heat transfer in periglacial landforms to represent the ground thermal regime of low‐altitude talus slopes. Our model solves for heat conduction and accounts explicitly for air convection adopting a Darcy term with a Boussinesq approximation for air circulation in the porous ground. Numerical model experiments for the low‐altitude talus slope Dreveneuse, Switzerland, confirm that air convection is the key to forming and maintaining ground ice. In the model, the porous talus slope is underlain by a layer of water‐bearing morainic material. In years, where the gradient between air and talus temperature is sufficiently large to result in increased convection and therefore cooling, ground ice forms due to air convection within the porous material and lasts for more than a year. It is only by considering convection that the model is able to represent the occurrences of ground ice, in accordance with temperature observations on‐site. These findings are important, as they confirm that ground ice can be formed and maintained in landforms with a mean annual air temperature > 0°C if ground air convection is present combined with the presence of water. |
author2 |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung |
format |
Article in Journal/Newspaper |
author |
Wicky, Jonas Hilbich, Christin Delaloye, Reynald Hauck, Christian |
spellingShingle |
Wicky, Jonas Hilbich, Christin Delaloye, Reynald Hauck, Christian Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope |
author_facet |
Wicky, Jonas Hilbich, Christin Delaloye, Reynald Hauck, Christian |
author_sort |
Wicky, Jonas |
title |
Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope |
title_short |
Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope |
title_full |
Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope |
title_fullStr |
Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope |
title_full_unstemmed |
Modeling the Link Between Air Convection and the Occurrence of Short‐Term Permafrost in a Low‐Altitude Cold Talus Slope |
title_sort |
modeling the link between air convection and the occurrence of short‐term permafrost in a low‐altitude cold talus slope |
publisher |
Wiley |
publishDate |
2024 |
url |
http://dx.doi.org/10.1002/ppp.2224 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ppp.2224 |
genre |
Ice permafrost Permafrost and Periglacial Processes |
genre_facet |
Ice permafrost Permafrost and Periglacial Processes |
op_source |
Permafrost and Periglacial Processes volume 35, issue 2, page 202-217 ISSN 1045-6740 1099-1530 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/ppp.2224 |
container_title |
Permafrost and Periglacial Processes |
_version_ |
1800753181570891776 |