A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions
An improved representation of the carbon cycle in permafrost regions will enable more realistic projections of the future climate–carbon system. Currently JULES (the Joint UK Land Environment Simulator) – the land surface model of the UK Earth System Model (UKESM) – uses the standard four-pool RothC...
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ftdoajarticles:oai:doaj.org/article:b54609ddd17d444d88966945ae9054c9 2023-05-15T17:56:52+02:00 A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions E. J. Burke S. E. Chadburn A. Ekici 2017-02-01T00:00:00Z https://doi.org/10.5194/gmd-10-959-2017 https://doaj.org/article/b54609ddd17d444d88966945ae9054c9 EN eng Copernicus Publications http://www.geosci-model-dev.net/10/959/2017/gmd-10-959-2017.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 1991-959X 1991-9603 doi:10.5194/gmd-10-959-2017 https://doaj.org/article/b54609ddd17d444d88966945ae9054c9 Geoscientific Model Development, Vol 10, Iss 2, Pp 959-975 (2017) Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/gmd-10-959-2017 2022-12-30T21:12:58Z An improved representation of the carbon cycle in permafrost regions will enable more realistic projections of the future climate–carbon system. Currently JULES (the Joint UK Land Environment Simulator) – the land surface model of the UK Earth System Model (UKESM) – uses the standard four-pool RothC soil carbon model. This paper describes a new version of JULES (vn4.3_permafrost) in which the soil vertical dimension is added to the soil carbon model, with a set of four pools in every soil layer. The respiration rate in each soil layer depends on the temperature and moisture conditions in that layer. Cryoturbation/bioturbation processes, which transfer soil carbon between layers, are represented by diffusive mixing. The litter inputs and the soil respiration are both parametrized to decrease with increasing depth. The model now includes a tracer so that selected soil carbon can be labelled and tracked through a simulation. Simulations show an improvement in the large-scale horizontal and vertical distribution of soil carbon over the standard version of JULES (vn4.3). Like the standard version of JULES, the vertically discretized model is still unable to simulate enough soil carbon in the tundra regions. This is in part because JULES underestimates the plant productivity over the tundra, but also because not all of the processes relevant for the accumulation of permafrost carbon, such as peat development, are included in the model. In comparison with the standard model, the vertically discretized model shows a delay in the onset of soil respiration in the spring, resulting in an increased net uptake of carbon during this time. In order to provide a more suitable representation of permafrost carbon for quantifying the permafrost carbon feedback within UKESM, the deep soil carbon in the permafrost region (below 1 m) was initialized using the observed soil carbon. There is now a slight drift in the soil carbon ( < 0.018 % decade −1 ), but the change in simulated soil carbon over the 20th century, when there is ... Article in Journal/Newspaper permafrost Tundra Directory of Open Access Journals: DOAJ Articles Jules ENVELOPE(140.917,140.917,-66.742,-66.742) Geoscientific Model Development 10 2 959 975 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
spellingShingle |
Geology QE1-996.5 E. J. Burke S. E. Chadburn A. Ekici A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions |
topic_facet |
Geology QE1-996.5 |
description |
An improved representation of the carbon cycle in permafrost regions will enable more realistic projections of the future climate–carbon system. Currently JULES (the Joint UK Land Environment Simulator) – the land surface model of the UK Earth System Model (UKESM) – uses the standard four-pool RothC soil carbon model. This paper describes a new version of JULES (vn4.3_permafrost) in which the soil vertical dimension is added to the soil carbon model, with a set of four pools in every soil layer. The respiration rate in each soil layer depends on the temperature and moisture conditions in that layer. Cryoturbation/bioturbation processes, which transfer soil carbon between layers, are represented by diffusive mixing. The litter inputs and the soil respiration are both parametrized to decrease with increasing depth. The model now includes a tracer so that selected soil carbon can be labelled and tracked through a simulation. Simulations show an improvement in the large-scale horizontal and vertical distribution of soil carbon over the standard version of JULES (vn4.3). Like the standard version of JULES, the vertically discretized model is still unable to simulate enough soil carbon in the tundra regions. This is in part because JULES underestimates the plant productivity over the tundra, but also because not all of the processes relevant for the accumulation of permafrost carbon, such as peat development, are included in the model. In comparison with the standard model, the vertically discretized model shows a delay in the onset of soil respiration in the spring, resulting in an increased net uptake of carbon during this time. In order to provide a more suitable representation of permafrost carbon for quantifying the permafrost carbon feedback within UKESM, the deep soil carbon in the permafrost region (below 1 m) was initialized using the observed soil carbon. There is now a slight drift in the soil carbon ( < 0.018 % decade −1 ), but the change in simulated soil carbon over the 20th century, when there is ... |
format |
Article in Journal/Newspaper |
author |
E. J. Burke S. E. Chadburn A. Ekici |
author_facet |
E. J. Burke S. E. Chadburn A. Ekici |
author_sort |
E. J. Burke |
title |
A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions |
title_short |
A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions |
title_full |
A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions |
title_fullStr |
A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions |
title_full_unstemmed |
A vertical representation of soil carbon in the JULES land surface scheme (vn4.3_permafrost) with a focus on permafrost regions |
title_sort |
vertical representation of soil carbon in the jules land surface scheme (vn4.3_permafrost) with a focus on permafrost regions |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/gmd-10-959-2017 https://doaj.org/article/b54609ddd17d444d88966945ae9054c9 |
long_lat |
ENVELOPE(140.917,140.917,-66.742,-66.742) |
geographic |
Jules |
geographic_facet |
Jules |
genre |
permafrost Tundra |
genre_facet |
permafrost Tundra |
op_source |
Geoscientific Model Development, Vol 10, Iss 2, Pp 959-975 (2017) |
op_relation |
http://www.geosci-model-dev.net/10/959/2017/gmd-10-959-2017.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 1991-959X 1991-9603 doi:10.5194/gmd-10-959-2017 https://doaj.org/article/b54609ddd17d444d88966945ae9054c9 |
op_doi |
https://doi.org/10.5194/gmd-10-959-2017 |
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Geoscientific Model Development |
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10 |
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959 |
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975 |
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