An improved representation of physical permafrost dynamics in the JULES land-surface model
International audience It is important to correctly simulate permafrost in global climate models, since the stored carbon represents the source of a potentially important climate feedback. This carbon feedback depends on the physical state of the permafrost. We have therefore included improved physi...
Published in: | Geoscientific Model Development |
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Main Authors: | , , , , , , , |
Other Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2015
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Online Access: | https://insu.hal.science/insu-01205181 https://insu.hal.science/insu-01205181/document https://insu.hal.science/insu-01205181/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20%20An%20improved%20representation%20of%20physical%20permafrost%20dynamics%20in%20the%20JULES%20land-surface%20model.pdf https://doi.org/10.5194/gmd-8-1493-2015 |
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Université Savoie Mont Blanc: HAL |
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ftunivsavoie |
language |
English |
topic |
[SDE]Environmental Sciences |
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[SDE]Environmental Sciences Chadburn, S. Burke, E. Essery, R. Boike, J. Langer, M. Heikenfeld, M. Cox, P. Friedlingstein, P. An improved representation of physical permafrost dynamics in the JULES land-surface model |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience It is important to correctly simulate permafrost in global climate models, since the stored carbon represents the source of a potentially important climate feedback. This carbon feedback depends on the physical state of the permafrost. We have therefore included improved physical permafrost processes in JULES (Joint UK Land Environment Simulator), which is the land-surface scheme used in the Hadley Centre climate models. The thermal and hydraulic properties of the soil were modified to account for the presence of organic matter, and the insulating effects of a surface layer of moss were added, allowing for fractional moss cover. These processes are particularly relevant in permafrost zones. We also simulate a higher-resolution soil column and deeper soil, and include an additional thermal column at the base of the soil to represent bedrock. In addition, the snow scheme was improved to allow it to run with arbitrarily thin layers. Point-site simulations at Samoylov Island, Siberia, show that the model is now able to simulate soil temperatures and thaw depth much closer to the observations. The root mean square error for the near-surface soil temperatures reduces by approximately 30%, and the active layer thickness is reduced from being over 1 m too deep to within 0.1 m of the observed active layer thickness. All of the model improvements contribute to improving the simulations, with organic matter having the single greatest impact. A new method is used to estimate active layer depth more accurately using the fraction of unfrozen water. Soil hydrology and snow are investigated further by holding the soil moisture fixed and adjusting the parameters to make the soil moisture and snow density match better with observations. The root mean square error in near-surface soil temperatures is reduced by a further 20% as a result. |
author2 |
University of Exeter Met Office Hadley Centre (MOHC) United Kingdom Met Office Exeter Grant Institute, The King’s Buildings, James Hutton Road, Edinburgh EH9 3FE, UK Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) University of Oxford |
format |
Article in Journal/Newspaper |
author |
Chadburn, S. Burke, E. Essery, R. Boike, J. Langer, M. Heikenfeld, M. Cox, P. Friedlingstein, P. |
author_facet |
Chadburn, S. Burke, E. Essery, R. Boike, J. Langer, M. Heikenfeld, M. Cox, P. Friedlingstein, P. |
author_sort |
Chadburn, S. |
title |
An improved representation of physical permafrost dynamics in the JULES land-surface model |
title_short |
An improved representation of physical permafrost dynamics in the JULES land-surface model |
title_full |
An improved representation of physical permafrost dynamics in the JULES land-surface model |
title_fullStr |
An improved representation of physical permafrost dynamics in the JULES land-surface model |
title_full_unstemmed |
An improved representation of physical permafrost dynamics in the JULES land-surface model |
title_sort |
improved representation of physical permafrost dynamics in the jules land-surface model |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://insu.hal.science/insu-01205181 https://insu.hal.science/insu-01205181/document https://insu.hal.science/insu-01205181/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20%20An%20improved%20representation%20of%20physical%20permafrost%20dynamics%20in%20the%20JULES%20land-surface%20model.pdf https://doi.org/10.5194/gmd-8-1493-2015 |
genre |
Active layer thickness permafrost Siberia |
genre_facet |
Active layer thickness permafrost Siberia |
op_source |
ISSN: 1991-9603 EISSN: 1991-959X Geoscientific Model Development https://insu.hal.science/insu-01205181 Geoscientific Model Development, 2015, 8 (5), pp.1493-1508. ⟨10.5194/gmd-8-1493-2015⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-8-1493-2015 insu-01205181 https://insu.hal.science/insu-01205181 https://insu.hal.science/insu-01205181/document https://insu.hal.science/insu-01205181/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20%20An%20improved%20representation%20of%20physical%20permafrost%20dynamics%20in%20the%20JULES%20land-surface%20model.pdf doi:10.5194/gmd-8-1493-2015 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/gmd-8-1493-2015 |
container_title |
Geoscientific Model Development |
container_volume |
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container_issue |
5 |
container_start_page |
1493 |
op_container_end_page |
1508 |
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1797587428149559296 |
spelling |
ftunivsavoie:oai:HAL:insu-01205181v1 2024-04-28T07:53:15+00:00 An improved representation of physical permafrost dynamics in the JULES land-surface model Chadburn, S. Burke, E. Essery, R. Boike, J. Langer, M. Heikenfeld, M. Cox, P. Friedlingstein, P. University of Exeter Met Office Hadley Centre (MOHC) United Kingdom Met Office Exeter Grant Institute, The King’s Buildings, James Hutton Road, Edinburgh EH9 3FE, UK Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI) Helmholtz-Gemeinschaft = Helmholtz Association Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) University of Oxford 2015-05 https://insu.hal.science/insu-01205181 https://insu.hal.science/insu-01205181/document https://insu.hal.science/insu-01205181/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20%20An%20improved%20representation%20of%20physical%20permafrost%20dynamics%20in%20the%20JULES%20land-surface%20model.pdf https://doi.org/10.5194/gmd-8-1493-2015 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/gmd-8-1493-2015 insu-01205181 https://insu.hal.science/insu-01205181 https://insu.hal.science/insu-01205181/document https://insu.hal.science/insu-01205181/file/GEOSCIENTIFIC%20MODEL%20DEVELOPMENT%20-%20%20An%20improved%20representation%20of%20physical%20permafrost%20dynamics%20in%20the%20JULES%20land-surface%20model.pdf doi:10.5194/gmd-8-1493-2015 info:eu-repo/semantics/OpenAccess ISSN: 1991-9603 EISSN: 1991-959X Geoscientific Model Development https://insu.hal.science/insu-01205181 Geoscientific Model Development, 2015, 8 (5), pp.1493-1508. ⟨10.5194/gmd-8-1493-2015⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2015 ftunivsavoie https://doi.org/10.5194/gmd-8-1493-2015 2024-04-11T01:02:23Z International audience It is important to correctly simulate permafrost in global climate models, since the stored carbon represents the source of a potentially important climate feedback. This carbon feedback depends on the physical state of the permafrost. We have therefore included improved physical permafrost processes in JULES (Joint UK Land Environment Simulator), which is the land-surface scheme used in the Hadley Centre climate models. The thermal and hydraulic properties of the soil were modified to account for the presence of organic matter, and the insulating effects of a surface layer of moss were added, allowing for fractional moss cover. These processes are particularly relevant in permafrost zones. We also simulate a higher-resolution soil column and deeper soil, and include an additional thermal column at the base of the soil to represent bedrock. In addition, the snow scheme was improved to allow it to run with arbitrarily thin layers. Point-site simulations at Samoylov Island, Siberia, show that the model is now able to simulate soil temperatures and thaw depth much closer to the observations. The root mean square error for the near-surface soil temperatures reduces by approximately 30%, and the active layer thickness is reduced from being over 1 m too deep to within 0.1 m of the observed active layer thickness. All of the model improvements contribute to improving the simulations, with organic matter having the single greatest impact. A new method is used to estimate active layer depth more accurately using the fraction of unfrozen water. Soil hydrology and snow are investigated further by holding the soil moisture fixed and adjusting the parameters to make the soil moisture and snow density match better with observations. The root mean square error in near-surface soil temperatures is reduced by a further 20% as a result. Article in Journal/Newspaper Active layer thickness permafrost Siberia Université Savoie Mont Blanc: HAL Geoscientific Model Development 8 5 1493 1508 |