The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter
The sensitivity of a global land-surface model projection of near-surface permafrost degradation is assessed with respect to explicit accounting of the thermal and hydrologic properties of soil organic matter and to a deepening of the soil column from 3.5 to 50 or more m. Together these modification...
Published in: | Journal of Geophysical Research |
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Language: | English |
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American Geophysical Union
2008
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Online Access: | http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-044 https://doi.org/10.1029/2007JF000883 |
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ftncar:oai:drupal-site.org:articles_6492 2023-10-01T03:53:55+02:00 The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter Lawrence, David (author) Slater, Andrew (author) Romanovsky, Vladimir (author) Nicolsky, Dmitry (author) 2008-05-06 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-044 https://doi.org/10.1029/2007JF000883 en eng American Geophysical Union Journal of Geophysical Research-Earth Surface http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-044 doi:10.1029/2007JF000883 ark:/85065/d7k64j86 An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union. Climate change Climate model Text article 2008 ftncar https://doi.org/10.1029/2007JF000883 2023-09-04T18:27:21Z The sensitivity of a global land-surface model projection of near-surface permafrost degradation is assessed with respect to explicit accounting of the thermal and hydrologic properties of soil organic matter and to a deepening of the soil column from 3.5 to 50 or more m. Together these modifications result in substantial improvements in the simulation of near-surface soil temperature in the Community Land Model (CLM). When forced off-line with archived data from a fully coupled Community Climate System Model (CCSM3) simulation of 20th century climate, the revised version of CLM produces a near-surface permafrost extent of 10.7 × 10⁶ km² (north of 45°N). This extent represents an improvement over the 8.5 × 10⁶ km²: simulated in the standard model and compares reasonably with observed estimates for continuous and discontinuous permafrost area (11.2-13.5 × 10⁶ km²). The total extent in the new model remains lower than observed because of biases in CCSM3 air temperature and/or snow depth. The rate of near-surface permafrost degradation, in response to strong simulated Arctic warming (∼ +7.5°C over Arctic land from 1900 to 2100, A1B greenhouse gas emissions scenario), is slower in the improved version of CLM, particularly during the early 21st century (81,000 versus 111,000 km² a⁻¹, where a is years). Even at the depressed rate, however, the warming is enough to drive near-surface permafrost extent sharply down by 2100. Experiments with a deep soil column exhibit a larger increase in ground heat flux than those without because of stronger near-surface vertical soil temperature gradients. This appears to lessen the sensitivity of soil temperature change to model soil depth. Article in Journal/Newspaper Arctic Climate change permafrost OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Arctic Journal of Geophysical Research 113 F2 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
topic |
Climate change Climate model |
spellingShingle |
Climate change Climate model The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter |
topic_facet |
Climate change Climate model |
description |
The sensitivity of a global land-surface model projection of near-surface permafrost degradation is assessed with respect to explicit accounting of the thermal and hydrologic properties of soil organic matter and to a deepening of the soil column from 3.5 to 50 or more m. Together these modifications result in substantial improvements in the simulation of near-surface soil temperature in the Community Land Model (CLM). When forced off-line with archived data from a fully coupled Community Climate System Model (CCSM3) simulation of 20th century climate, the revised version of CLM produces a near-surface permafrost extent of 10.7 × 10⁶ km² (north of 45°N). This extent represents an improvement over the 8.5 × 10⁶ km²: simulated in the standard model and compares reasonably with observed estimates for continuous and discontinuous permafrost area (11.2-13.5 × 10⁶ km²). The total extent in the new model remains lower than observed because of biases in CCSM3 air temperature and/or snow depth. The rate of near-surface permafrost degradation, in response to strong simulated Arctic warming (∼ +7.5°C over Arctic land from 1900 to 2100, A1B greenhouse gas emissions scenario), is slower in the improved version of CLM, particularly during the early 21st century (81,000 versus 111,000 km² a⁻¹, where a is years). Even at the depressed rate, however, the warming is enough to drive near-surface permafrost extent sharply down by 2100. Experiments with a deep soil column exhibit a larger increase in ground heat flux than those without because of stronger near-surface vertical soil temperature gradients. This appears to lessen the sensitivity of soil temperature change to model soil depth. |
author2 |
Lawrence, David (author) Slater, Andrew (author) Romanovsky, Vladimir (author) Nicolsky, Dmitry (author) |
format |
Article in Journal/Newspaper |
title |
The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter |
title_short |
The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter |
title_full |
The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter |
title_fullStr |
The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter |
title_full_unstemmed |
The sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter |
title_sort |
sensitivity of a model projection of near-surface permafrost degradation to soil column depth and inclusion of soil organic matter |
publisher |
American Geophysical Union |
publishDate |
2008 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-044 https://doi.org/10.1029/2007JF000883 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Climate change permafrost |
genre_facet |
Arctic Climate change permafrost |
op_relation |
Journal of Geophysical Research-Earth Surface http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-003-044 doi:10.1029/2007JF000883 ark:/85065/d7k64j86 |
op_rights |
An edited version of this paper was published by AGU. Copyright 2008 American Geophysical Union. |
op_doi |
https://doi.org/10.1029/2007JF000883 |
container_title |
Journal of Geophysical Research |
container_volume |
113 |
container_issue |
F2 |
_version_ |
1778521001315794944 |