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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Published in:The Cryosphere
Other Authors: Peng, S. (author), Ciais, P. (author), Krinner, G. (author), Wang, T. (author), Gouttevin, I. (author), McGuire, A. (author), Lawrence, David (author), Burke, E. (author), Chen, X. (author), Decharme, B. (author), Koven, C. (author), MacDougall, A. (author), Rinke, A. (author), Saito, K. (author), Zhang, W. (author), Alkama, R. (author), Bohn, T. (author), Delire, C. (author), Hajima, T. (author), Ji, D. (author), Lettenmaier, D. (author), Miller, P. (author), Moore, J. (author), Smith, B. (author), Sueyoshi, T. (author)
Format: Article in Journal/Newspaper
Language:English
Published: 2016
Subjects:
Online Access:http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-023-030
https://doi.org/10.5194/tc-10-179-2016
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spelling ftncar:oai:drupal-site.org:articles_18575 2023-09-05T13:11:11+02:00 Simulated high-latitude soil thermal dynamics during the past 4 decades Peng, S. (author) Ciais, P. (author) Krinner, G. (author) Wang, T. (author) Gouttevin, I. (author) McGuire, A. (author) Lawrence, David (author) Burke, E. (author) Chen, X. (author) Decharme, B. (author) Koven, C. (author) MacDougall, A. (author) Rinke, A. (author) Saito, K. (author) Zhang, W. (author) Alkama, R. (author) Bohn, T. (author) Delire, C. (author) Hajima, T. (author) Ji, D. (author) Lettenmaier, D. (author) Miller, P. (author) Moore, J. (author) Smith, B. (author) Sueyoshi, T. (author) 2016-01-10 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-023-030 https://doi.org/10.5194/tc-10-179-2016 en eng The Cryosphere articles:18575 ark:/85065/d728097c http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-023-030 doi:10.5194/tc-10-179-2016 Copyright 2016 Authors. This work is distributed under the Creative Commons Attribution 3.0 License. Text article 2016 ftncar https://doi.org/10.5194/tc-10-179-2016 2023-08-14T18:43:25Z 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 (Tsub>a) 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 3 m loss rate, is found to be significantly correlated with the magnitude of the trends of Ts at 1 m 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 1 ... Article in Journal/Newspaper Active layer thickness permafrost The Cryosphere OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) The Cryosphere 10 1 179 192
institution Open Polar
collection OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research)
op_collection_id ftncar
language English
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 (Tsub>a) 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 3 m loss rate, is found to be significantly correlated with the magnitude of the trends of Ts at 1 m 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 1 ...
author2 Peng, S. (author)
Ciais, P. (author)
Krinner, G. (author)
Wang, T. (author)
Gouttevin, I. (author)
McGuire, A. (author)
Lawrence, David (author)
Burke, E. (author)
Chen, X. (author)
Decharme, B. (author)
Koven, C. (author)
MacDougall, A. (author)
Rinke, A. (author)
Saito, K. (author)
Zhang, W. (author)
Alkama, R. (author)
Bohn, T. (author)
Delire, C. (author)
Hajima, T. (author)
Ji, D. (author)
Lettenmaier, D. (author)
Miller, P. (author)
Moore, J. (author)
Smith, B. (author)
Sueyoshi, T. (author)
format Article in Journal/Newspaper
title Simulated high-latitude soil thermal dynamics during the past 4 decades
spellingShingle 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
publishDate 2016
url http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-023-030
https://doi.org/10.5194/tc-10-179-2016
genre Active layer thickness
permafrost
The Cryosphere
genre_facet Active layer thickness
permafrost
The Cryosphere
op_relation The Cryosphere
articles:18575
ark:/85065/d728097c
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-023-030
doi:10.5194/tc-10-179-2016
op_rights Copyright 2016 Authors. This work is distributed under the Creative Commons Attribution 3.0 License.
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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