Simulated high-latitude soil thermal dynamics during the past 4 decades
Soil temperature (Ts) change is a key indicator of the dynamics of permafrost. On seasonal and interannual timescales, the variability of Ts determines the active-layer depth, which regulates hydrological soil properties and biogeochemical processes. On the multi-decadal scale, increasing Ts not onl...
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2016
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Online Access: | https://doi.org/10.5194/tc-10-179-2016 http://handle.westernsydney.edu.au:8081/1959.7/uws:48455 |
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ftunivwestsyd:oai:researchdirect.westernsydney.edu.au:uws_48455 2023-05-15T13:03:21+02:00 Simulated high-latitude soil thermal dynamics during the past 4 decades Peng, Shushi Ciais, Philippe Krinner, Gerhard Wang, T. Gouttevin, Isabelle McGuire, Anthony D. Lawrence, David M. Burke, Eleanor J. Chen, Xiaodong Decharme, Bertrand Koven, Charles D. MacDougall, Andrew H. Rinke, Annette Saito, Kazuyuki Zhang, Wenxin Alkama, Ramdane Bohn, Theodore J. Delire, Christine Hajima, Tomohiro Ji, Duoying Lettenmaier, Dennis P. Miller, Paul A. Moore, John C. Smith, Benjamin (R19508) Sueyoshi, Tetsuo Hawkesbury Institute for the Environment (Host institution) 2016 print 14 https://doi.org/10.5194/tc-10-179-2016 http://handle.westernsydney.edu.au:8081/1959.7/uws:48455 eng eng Germany, Copernicus The Cryosphere--1994-0416--1994-0424 Vol. 10 Issue. 1 No. pp: 179-192 © Author(s) 2016. CC Attribution 3.0 License. CC-BY XXXXXX - Unknown soil temperature permafrost thermal conductivity journal article 2016 ftunivwestsyd https://doi.org/10.5194/tc-10-179-2016 2020-12-05T17:54:37Z Soil temperature (Ts) change is a key indicator of the dynamics of permafrost. On seasonal and interannual timescales, the variability of Ts determines the active-layer depth, which regulates hydrological soil properties and biogeochemical processes. On the multi-decadal scale, increasing Ts not only drives permafrost thaw/retreat but can also trigger and accelerate the decomposition of soil organic carbon. The magnitude of permafrost carbon feedbacks is thus closely linked to the rate of change of soil thermal regimes. In this study, we used nine process-based ecosystem models with permafrost processes, all forced by different observation-based climate forcing during the period 1960–2000, to characterize the warming rate of Ts in permafrost regions. There is a large spread of Ts trends at 20 cm depth across the models, with trend values ranging from 0.010 ± 0.003 to 0.031 ± 0.005 _C yr-1. Most models show smaller increase in Ts with increasing depth. Air temperature (Ta/ and longwave downward radiation (LWDR) are the main drivers of Ts trends, but their relative contributions differ amongst the models. Different trends of LWDR used in the forcing of models can explain 61% of their differences in Ts trends, while trends of Ta only explain 5% of the differences in Ts trends. Uncertain climate forcing contributes a larger uncertainty in Ts trends (0.021_0.008 _C yr-1, mean ± standard deviation) than the uncertainty of model structure (0.012 ± 0.001 °C yr-1/, diagnosed from the range of response between different models, normalized to the same forcing. In addition, the loss rate of near-surface permafrost area, defined as total area where the maximum seasonal active-layer thickness (ALT) is less than 3m loss rate, is found to be significantly correlated with the magnitude of the trends of Ts at 1m depth across the models (R = -0.85, P = 0.003), but not with the initial total near-surface permafrost area (R = -0.30, P = 0.438). The sensitivity of the total boreal near-surface permafrost area to Ts at 1m is estimated to be of -2.80 ± 0.67 million km2 °C-1. Finally, by using two long-term LWDR data sets and relationships between trends of LWDR and Ts across models, we infer an observation-constrained total boreal near-surface permafrost area decrease comprising between 39 ± 14 X 103 and 75 ± 14 X 103 km2 yr-1 from 1960 to 2000. This corresponds to 9–18% degradation of the current permafrost area. Article in Journal/Newspaper Active layer thickness permafrost The Cryosphere University of Western Sydney (UWS): Research Direct The Cryosphere 10 1 179 192 |
institution |
Open Polar |
collection |
University of Western Sydney (UWS): Research Direct |
op_collection_id |
ftunivwestsyd |
language |
English |
topic |
XXXXXX - Unknown soil temperature permafrost thermal conductivity |
spellingShingle |
XXXXXX - Unknown soil temperature permafrost thermal conductivity Peng, Shushi Ciais, Philippe Krinner, Gerhard Wang, T. Gouttevin, Isabelle McGuire, Anthony D. Lawrence, David M. Burke, Eleanor J. Chen, Xiaodong Decharme, Bertrand Koven, Charles D. MacDougall, Andrew H. Rinke, Annette Saito, Kazuyuki Zhang, Wenxin Alkama, Ramdane Bohn, Theodore J. Delire, Christine Hajima, Tomohiro Ji, Duoying Lettenmaier, Dennis P. Miller, Paul A. Moore, John C. Smith, Benjamin (R19508) Sueyoshi, Tetsuo Simulated high-latitude soil thermal dynamics during the past 4 decades |
topic_facet |
XXXXXX - Unknown soil temperature permafrost thermal conductivity |
description |
Soil temperature (Ts) change is a key indicator of the dynamics of permafrost. On seasonal and interannual timescales, the variability of Ts determines the active-layer depth, which regulates hydrological soil properties and biogeochemical processes. On the multi-decadal scale, increasing Ts not only drives permafrost thaw/retreat but can also trigger and accelerate the decomposition of soil organic carbon. The magnitude of permafrost carbon feedbacks is thus closely linked to the rate of change of soil thermal regimes. In this study, we used nine process-based ecosystem models with permafrost processes, all forced by different observation-based climate forcing during the period 1960–2000, to characterize the warming rate of Ts in permafrost regions. There is a large spread of Ts trends at 20 cm depth across the models, with trend values ranging from 0.010 ± 0.003 to 0.031 ± 0.005 _C yr-1. Most models show smaller increase in Ts with increasing depth. Air temperature (Ta/ and longwave downward radiation (LWDR) are the main drivers of Ts trends, but their relative contributions differ amongst the models. Different trends of LWDR used in the forcing of models can explain 61% of their differences in Ts trends, while trends of Ta only explain 5% of the differences in Ts trends. Uncertain climate forcing contributes a larger uncertainty in Ts trends (0.021_0.008 _C yr-1, mean ± standard deviation) than the uncertainty of model structure (0.012 ± 0.001 °C yr-1/, diagnosed from the range of response between different models, normalized to the same forcing. In addition, the loss rate of near-surface permafrost area, defined as total area where the maximum seasonal active-layer thickness (ALT) is less than 3m loss rate, is found to be significantly correlated with the magnitude of the trends of Ts at 1m depth across the models (R = -0.85, P = 0.003), but not with the initial total near-surface permafrost area (R = -0.30, P = 0.438). The sensitivity of the total boreal near-surface permafrost area to Ts at 1m is estimated to be of -2.80 ± 0.67 million km2 °C-1. Finally, by using two long-term LWDR data sets and relationships between trends of LWDR and Ts across models, we infer an observation-constrained total boreal near-surface permafrost area decrease comprising between 39 ± 14 X 103 and 75 ± 14 X 103 km2 yr-1 from 1960 to 2000. This corresponds to 9–18% degradation of the current permafrost area. |
author2 |
Hawkesbury Institute for the Environment (Host institution) |
format |
Article in Journal/Newspaper |
author |
Peng, Shushi Ciais, Philippe Krinner, Gerhard Wang, T. Gouttevin, Isabelle McGuire, Anthony D. Lawrence, David M. Burke, Eleanor J. Chen, Xiaodong Decharme, Bertrand Koven, Charles D. MacDougall, Andrew H. Rinke, Annette Saito, Kazuyuki Zhang, Wenxin Alkama, Ramdane Bohn, Theodore J. Delire, Christine Hajima, Tomohiro Ji, Duoying Lettenmaier, Dennis P. Miller, Paul A. Moore, John C. Smith, Benjamin (R19508) Sueyoshi, Tetsuo |
author_facet |
Peng, Shushi Ciais, Philippe Krinner, Gerhard Wang, T. Gouttevin, Isabelle McGuire, Anthony D. Lawrence, David M. Burke, Eleanor J. Chen, Xiaodong Decharme, Bertrand Koven, Charles D. MacDougall, Andrew H. Rinke, Annette Saito, Kazuyuki Zhang, Wenxin Alkama, Ramdane Bohn, Theodore J. Delire, Christine Hajima, Tomohiro Ji, Duoying Lettenmaier, Dennis P. Miller, Paul A. Moore, John C. Smith, Benjamin (R19508) Sueyoshi, Tetsuo |
author_sort |
Peng, Shushi |
title |
Simulated high-latitude soil thermal dynamics during the past 4 decades |
title_short |
Simulated high-latitude soil thermal dynamics during the past 4 decades |
title_full |
Simulated high-latitude soil thermal dynamics during the past 4 decades |
title_fullStr |
Simulated high-latitude soil thermal dynamics during the past 4 decades |
title_full_unstemmed |
Simulated high-latitude soil thermal dynamics during the past 4 decades |
title_sort |
simulated high-latitude soil thermal dynamics during the past 4 decades |
publisher |
Germany, Copernicus |
publishDate |
2016 |
url |
https://doi.org/10.5194/tc-10-179-2016 http://handle.westernsydney.edu.au:8081/1959.7/uws:48455 |
genre |
Active layer thickness permafrost The Cryosphere |
genre_facet |
Active layer thickness permafrost The Cryosphere |
op_relation |
The Cryosphere--1994-0416--1994-0424 Vol. 10 Issue. 1 No. pp: 179-192 |
op_rights |
© Author(s) 2016. CC Attribution 3.0 License. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-10-179-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
1 |
container_start_page |
179 |
op_container_end_page |
192 |
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1766334642544181248 |