Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau
Seasonally variable thermal conductivity in active layers is one important factor that controls the thermal state of permafrost. The common assumption is that this conductivity is considerably lower in the thawed than in the frozen state, λ t / λ f < 1. Using a 9-year dataset from the Qinghai–Tib...
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ftcopernicus:oai:publications.copernicus.org:tc48134 2023-05-15T17:56:30+02:00 Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau Pan, Xicai Li, Yanping Yu, Qihao Shi, Xiaogang Yang, Daqing Roth, Kurt 2018-09-27 application/pdf https://doi.org/10.5194/tc-10-1591-2016 https://tc.copernicus.org/articles/10/1591/2016/ eng eng doi:10.5194/tc-10-1591-2016 https://tc.copernicus.org/articles/10/1591/2016/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-10-1591-2016 2020-07-20T16:24:03Z Seasonally variable thermal conductivity in active layers is one important factor that controls the thermal state of permafrost. The common assumption is that this conductivity is considerably lower in the thawed than in the frozen state, λ t / λ f < 1. Using a 9-year dataset from the Qinghai–Tibet Plateau (QTP) in conjunction with the GEOtop model, we demonstrate that the ratio λ t / λ f may approach or even exceed 1. This can happen in thick (> 1.5 m) active layers with strong seasonal total water content changes in the regions with summer-monsoon-dominated precipitation pattern. The conductivity ratio can be further increased by typical soil architectures that may lead to a dry interlayer. The unique pattern of soil hydraulic and thermal dynamics in the active layer can be one important contributor for the rapid permafrost warming at the study site. These findings suggest that, given the increase in air temperature and precipitation, soil hydraulic properties, particularly soil architecture in those thick active layers must be properly taken into account in permafrost models. Text permafrost Copernicus Publications: E-Journals The Cryosphere 10 4 1591 1603 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
Seasonally variable thermal conductivity in active layers is one important factor that controls the thermal state of permafrost. The common assumption is that this conductivity is considerably lower in the thawed than in the frozen state, λ t / λ f < 1. Using a 9-year dataset from the Qinghai–Tibet Plateau (QTP) in conjunction with the GEOtop model, we demonstrate that the ratio λ t / λ f may approach or even exceed 1. This can happen in thick (> 1.5 m) active layers with strong seasonal total water content changes in the regions with summer-monsoon-dominated precipitation pattern. The conductivity ratio can be further increased by typical soil architectures that may lead to a dry interlayer. The unique pattern of soil hydraulic and thermal dynamics in the active layer can be one important contributor for the rapid permafrost warming at the study site. These findings suggest that, given the increase in air temperature and precipitation, soil hydraulic properties, particularly soil architecture in those thick active layers must be properly taken into account in permafrost models. |
format |
Text |
author |
Pan, Xicai Li, Yanping Yu, Qihao Shi, Xiaogang Yang, Daqing Roth, Kurt |
spellingShingle |
Pan, Xicai Li, Yanping Yu, Qihao Shi, Xiaogang Yang, Daqing Roth, Kurt Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau |
author_facet |
Pan, Xicai Li, Yanping Yu, Qihao Shi, Xiaogang Yang, Daqing Roth, Kurt |
author_sort |
Pan, Xicai |
title |
Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau |
title_short |
Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau |
title_full |
Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau |
title_fullStr |
Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau |
title_full_unstemmed |
Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau |
title_sort |
effects of stratified active layers on high-altitude permafrost warming: a case study on the qinghai–tibet plateau |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-10-1591-2016 https://tc.copernicus.org/articles/10/1591/2016/ |
genre |
permafrost |
genre_facet |
permafrost |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-10-1591-2016 https://tc.copernicus.org/articles/10/1591/2016/ |
op_doi |
https://doi.org/10.5194/tc-10-1591-2016 |
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The Cryosphere |
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10 |
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4 |
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1591 |
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1603 |
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