Numerical modelling of convective heat transport by air flow in permafrost talus slopes
Talus slopes are a widespread geomorphic feature in the Alps. Due to their high porosity a gravity-driven internal air circulation can be established which is forced by the gradient between external (air) and internal (talus) temperature. The thermal regime is different from the surrounding environm...
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2017
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Online Access: | https://doi.org/10.5194/tc-11-1311-2017 https://doaj.org/article/a6d719c2921c48f482bec001d261b4c1 |
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ftdoajarticles:oai:doaj.org/article:a6d719c2921c48f482bec001d261b4c1 2023-05-15T17:56:59+02:00 Numerical modelling of convective heat transport by air flow in permafrost talus slopes J. Wicky C. Hauck 2017-06-01T00:00:00Z https://doi.org/10.5194/tc-11-1311-2017 https://doaj.org/article/a6d719c2921c48f482bec001d261b4c1 EN eng Copernicus Publications http://www.the-cryosphere.net/11/1311/2017/tc-11-1311-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-11-1311-2017 1994-0416 1994-0424 https://doaj.org/article/a6d719c2921c48f482bec001d261b4c1 The Cryosphere, Vol 11, Pp 1311-1325 (2017) Environmental sciences GE1-350 Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/tc-11-1311-2017 2022-12-31T10:57:11Z Talus slopes are a widespread geomorphic feature in the Alps. Due to their high porosity a gravity-driven internal air circulation can be established which is forced by the gradient between external (air) and internal (talus) temperature. The thermal regime is different from the surrounding environment, leading to the occurrence of permafrost below the typical permafrost zone. This phenomenon has mainly been analysed by field studies and only few explicit numerical modelling studies exist. Numerical simulations of permafrost sometimes use parameterisations for the effects of convection but mostly neglect the influence of convective heat transfer in air on the thermal regime. In contrast, in civil engineering many studies have been carried out to investigate the thermal behaviour of blocky layers and to improve their passive cooling effect. The present study further develops and applies these concepts to model heat transfer in air flows in a natural-scale talus slope. Modelling results show that convective heat transfer has the potential to develop a significant temperature difference between the lower and the upper parts of the talus slope. A seasonally alternating chimney-effect type of circulation develops. Modelling results also show that this convective heat transfer leads to the formation of a cold reservoir in the lower part of the talus slope, which can be crucial for maintaining the frozen ground conditions despite increasing air temperatures caused by climate change. Article in Journal/Newspaper permafrost The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 11 3 1311 1325 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 J. Wicky C. Hauck Numerical modelling of convective heat transport by air flow in permafrost talus slopes |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Talus slopes are a widespread geomorphic feature in the Alps. Due to their high porosity a gravity-driven internal air circulation can be established which is forced by the gradient between external (air) and internal (talus) temperature. The thermal regime is different from the surrounding environment, leading to the occurrence of permafrost below the typical permafrost zone. This phenomenon has mainly been analysed by field studies and only few explicit numerical modelling studies exist. Numerical simulations of permafrost sometimes use parameterisations for the effects of convection but mostly neglect the influence of convective heat transfer in air on the thermal regime. In contrast, in civil engineering many studies have been carried out to investigate the thermal behaviour of blocky layers and to improve their passive cooling effect. The present study further develops and applies these concepts to model heat transfer in air flows in a natural-scale talus slope. Modelling results show that convective heat transfer has the potential to develop a significant temperature difference between the lower and the upper parts of the talus slope. A seasonally alternating chimney-effect type of circulation develops. Modelling results also show that this convective heat transfer leads to the formation of a cold reservoir in the lower part of the talus slope, which can be crucial for maintaining the frozen ground conditions despite increasing air temperatures caused by climate change. |
format |
Article in Journal/Newspaper |
author |
J. Wicky C. Hauck |
author_facet |
J. Wicky C. Hauck |
author_sort |
J. Wicky |
title |
Numerical modelling of convective heat transport by air flow in permafrost talus slopes |
title_short |
Numerical modelling of convective heat transport by air flow in permafrost talus slopes |
title_full |
Numerical modelling of convective heat transport by air flow in permafrost talus slopes |
title_fullStr |
Numerical modelling of convective heat transport by air flow in permafrost talus slopes |
title_full_unstemmed |
Numerical modelling of convective heat transport by air flow in permafrost talus slopes |
title_sort |
numerical modelling of convective heat transport by air flow in permafrost talus slopes |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-1311-2017 https://doaj.org/article/a6d719c2921c48f482bec001d261b4c1 |
genre |
permafrost The Cryosphere |
genre_facet |
permafrost The Cryosphere |
op_source |
The Cryosphere, Vol 11, Pp 1311-1325 (2017) |
op_relation |
http://www.the-cryosphere.net/11/1311/2017/tc-11-1311-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-11-1311-2017 1994-0416 1994-0424 https://doaj.org/article/a6d719c2921c48f482bec001d261b4c1 |
op_doi |
https://doi.org/10.5194/tc-11-1311-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
3 |
container_start_page |
1311 |
op_container_end_page |
1325 |
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1766165324784205824 |