Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model
To address the long-standing underrepresentation of the influences of highly variable ground ice content on the trajectory of permafrost conditions simulated in Earth system models under a warming climate, we implement a sub-grid representation of excess ground ice within permafrost soils using the...
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Online Access: | https://doi.org/10.5194/tc-14-4611-2020 https://tc.copernicus.org/articles/14/4611/2020/tc-14-4611-2020.pdf https://doaj.org/article/9607c4fc5ebd47669e1a9cc68268a5a3 |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:9607c4fc5ebd47669e1a9cc68268a5a3 2023-05-15T15:02:20+02:00 Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model L. Cai H. Lee K. S. Aas S. Westermann 2020-12-01 https://doi.org/10.5194/tc-14-4611-2020 https://tc.copernicus.org/articles/14/4611/2020/tc-14-4611-2020.pdf https://doaj.org/article/9607c4fc5ebd47669e1a9cc68268a5a3 en eng Copernicus Publications doi:10.5194/tc-14-4611-2020 1994-0416 1994-0424 https://tc.copernicus.org/articles/14/4611/2020/tc-14-4611-2020.pdf https://doaj.org/article/9607c4fc5ebd47669e1a9cc68268a5a3 undefined The Cryosphere, Vol 14, Pp 4611-4626 (2020) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2020 fttriple https://doi.org/10.5194/tc-14-4611-2020 2023-01-22T19:05:19Z To address the long-standing underrepresentation of the influences of highly variable ground ice content on the trajectory of permafrost conditions simulated in Earth system models under a warming climate, we implement a sub-grid representation of excess ground ice within permafrost soils using the latest version of the Community Land Model (CLM5). Based on the original CLM5 tiling hierarchy, we duplicate the natural vegetated land unit by building extra tiles for up to three cryostratigraphies with different amounts of excess ice for each grid cell. For the same total amount of excess ice, introducing sub-grid variability in excess-ice contents leads to different excess-ice melting rates at the grid level. In addition, there are impacts on permafrost thermal properties and local hydrology with sub-grid representation. We evaluate this new development with single-point simulations at the Lena River delta, Siberia, where three sub-regions with distinctively different excess-ice conditions are observed. A triple-land-unit case accounting for this spatial variability conforms well to previous model studies for the Lena River delta and displays markedly different dynamics of future excess-ice thaw compared to a single-land-unit case initialized with average excess-ice contents. For global simulations, we prescribed a tiling scheme combined with our sub-grid representation to the global permafrost region using presently available circum-Arctic ground ice data. The sub-grid-scale excess ice produces significant melting of excess ice under a warming climate and enhances the representation of sub-grid variability of surface subsidence on a global scale. Our model development makes it possible to portray more details on the permafrost degradation trajectory depending on the sub-grid soil thermal regime and excess-ice melting, which also shows a strong indication that accounting for excess ice is a prerequisite of a reasonable projection of permafrost thaw. The modeled permafrost degradation with sub-grid excess ice ... Article in Journal/Newspaper Arctic Ice lena river permafrost The Cryosphere Siberia Unknown Arctic The Cryosphere 14 12 4611 4626 |
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geo envir L. Cai H. Lee K. S. Aas S. Westermann Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model |
topic_facet |
geo envir |
description |
To address the long-standing underrepresentation of the influences of highly variable ground ice content on the trajectory of permafrost conditions simulated in Earth system models under a warming climate, we implement a sub-grid representation of excess ground ice within permafrost soils using the latest version of the Community Land Model (CLM5). Based on the original CLM5 tiling hierarchy, we duplicate the natural vegetated land unit by building extra tiles for up to three cryostratigraphies with different amounts of excess ice for each grid cell. For the same total amount of excess ice, introducing sub-grid variability in excess-ice contents leads to different excess-ice melting rates at the grid level. In addition, there are impacts on permafrost thermal properties and local hydrology with sub-grid representation. We evaluate this new development with single-point simulations at the Lena River delta, Siberia, where three sub-regions with distinctively different excess-ice conditions are observed. A triple-land-unit case accounting for this spatial variability conforms well to previous model studies for the Lena River delta and displays markedly different dynamics of future excess-ice thaw compared to a single-land-unit case initialized with average excess-ice contents. For global simulations, we prescribed a tiling scheme combined with our sub-grid representation to the global permafrost region using presently available circum-Arctic ground ice data. The sub-grid-scale excess ice produces significant melting of excess ice under a warming climate and enhances the representation of sub-grid variability of surface subsidence on a global scale. Our model development makes it possible to portray more details on the permafrost degradation trajectory depending on the sub-grid soil thermal regime and excess-ice melting, which also shows a strong indication that accounting for excess ice is a prerequisite of a reasonable projection of permafrost thaw. The modeled permafrost degradation with sub-grid excess ice ... |
format |
Article in Journal/Newspaper |
author |
L. Cai H. Lee K. S. Aas S. Westermann |
author_facet |
L. Cai H. Lee K. S. Aas S. Westermann |
author_sort |
L. Cai |
title |
Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model |
title_short |
Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model |
title_full |
Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model |
title_fullStr |
Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model |
title_full_unstemmed |
Projecting circum-Arctic excess-ground-ice melt with a sub-grid representation in the Community Land Model |
title_sort |
projecting circum-arctic excess-ground-ice melt with a sub-grid representation in the community land model |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-4611-2020 https://tc.copernicus.org/articles/14/4611/2020/tc-14-4611-2020.pdf https://doaj.org/article/9607c4fc5ebd47669e1a9cc68268a5a3 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Ice lena river permafrost The Cryosphere Siberia |
genre_facet |
Arctic Ice lena river permafrost The Cryosphere Siberia |
op_source |
The Cryosphere, Vol 14, Pp 4611-4626 (2020) |
op_relation |
doi:10.5194/tc-14-4611-2020 1994-0416 1994-0424 https://tc.copernicus.org/articles/14/4611/2020/tc-14-4611-2020.pdf https://doaj.org/article/9607c4fc5ebd47669e1a9cc68268a5a3 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-14-4611-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
12 |
container_start_page |
4611 |
op_container_end_page |
4626 |
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1766334303252250624 |