Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0

The precise magnitude and timing of permafrost-thaw-related emissions and their subsequent impact on the global climate system remain highly uncertain. This uncertainty stems from the complex quantification of the rate and extent of permafrost thaw, which is influenced by factors such as sensitivity...

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Main Authors: Damseaux, Adrien, Matthes, Heidrun, Dutch, Victoria R., Wake, Leanne, Rutter, Nick
Format: Text
Language:English
Published: 2024
Subjects:
Online Access:https://doi.org/10.5194/egusphere-2024-1412
https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1412/
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spelling ftcopernicus:oai:publications.copernicus.org:egusphere120222 2024-09-15T18:29:18+00:00 Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0 Damseaux, Adrien Matthes, Heidrun Dutch, Victoria R. Wake, Leanne Rutter, Nick 2024-06-12 application/pdf https://doi.org/10.5194/egusphere-2024-1412 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1412/ eng eng doi:10.5194/egusphere-2024-1412 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1412/ eISSN: Text 2024 ftcopernicus https://doi.org/10.5194/egusphere-2024-1412 2024-08-28T05:24:22Z The precise magnitude and timing of permafrost-thaw-related emissions and their subsequent impact on the global climate system remain highly uncertain. This uncertainty stems from the complex quantification of the rate and extent of permafrost thaw, which is influenced by factors such as sensitivity to surface properties like snow cover. Acting as a thermal insulator, snow cover directly influences surface energy fluxes and can significantly impact the permafrost thermal regime. However, current Earth System Models often inadequately represent the nuanced effects of snow cover in permafrost regions, leading to inaccuracies in simulating soil temperatures and permafrost dynamics. Notably, CLM5.0 tends to overestimate snowpack thermal conductivity over permafrost regions, resulting in an underestimation of the snow insulating capacity. By using a snow thermal conductivity scheme better adapted for snowpack typically found in permafrost regions, we seek to resolve thermal insulation underestimation and assess the influence of snow on simulated soil temperatures and permafrost dynamics. Evaluation using two Arctic-wide soil temperature observation datasets reveals that the new snow thermal conductivity scheme noticeably reduces the cold soil temperature bias (RMSE = 3.17 to 2.4 °C, using remote sensing data; RMSE = 3.9 to 2.19 °C, using in-situ data) and effectively addresses the overestimation of permafrost extent present when using the default parameterizations of CLM5.0. Text permafrost Copernicus Publications: E-Journals
institution Open Polar
collection Copernicus Publications: E-Journals
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language English
description The precise magnitude and timing of permafrost-thaw-related emissions and their subsequent impact on the global climate system remain highly uncertain. This uncertainty stems from the complex quantification of the rate and extent of permafrost thaw, which is influenced by factors such as sensitivity to surface properties like snow cover. Acting as a thermal insulator, snow cover directly influences surface energy fluxes and can significantly impact the permafrost thermal regime. However, current Earth System Models often inadequately represent the nuanced effects of snow cover in permafrost regions, leading to inaccuracies in simulating soil temperatures and permafrost dynamics. Notably, CLM5.0 tends to overestimate snowpack thermal conductivity over permafrost regions, resulting in an underestimation of the snow insulating capacity. By using a snow thermal conductivity scheme better adapted for snowpack typically found in permafrost regions, we seek to resolve thermal insulation underestimation and assess the influence of snow on simulated soil temperatures and permafrost dynamics. Evaluation using two Arctic-wide soil temperature observation datasets reveals that the new snow thermal conductivity scheme noticeably reduces the cold soil temperature bias (RMSE = 3.17 to 2.4 °C, using remote sensing data; RMSE = 3.9 to 2.19 °C, using in-situ data) and effectively addresses the overestimation of permafrost extent present when using the default parameterizations of CLM5.0.
format Text
author Damseaux, Adrien
Matthes, Heidrun
Dutch, Victoria R.
Wake, Leanne
Rutter, Nick
spellingShingle Damseaux, Adrien
Matthes, Heidrun
Dutch, Victoria R.
Wake, Leanne
Rutter, Nick
Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0
author_facet Damseaux, Adrien
Matthes, Heidrun
Dutch, Victoria R.
Wake, Leanne
Rutter, Nick
author_sort Damseaux, Adrien
title Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0
title_short Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0
title_full Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0
title_fullStr Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0
title_full_unstemmed Impact of Snow Thermal Conductivity Schemes on pan-Arctic Permafrost Dynamics in CLM5.0
title_sort impact of snow thermal conductivity schemes on pan-arctic permafrost dynamics in clm5.0
publishDate 2024
url https://doi.org/10.5194/egusphere-2024-1412
https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1412/
genre permafrost
genre_facet permafrost
op_source eISSN:
op_relation doi:10.5194/egusphere-2024-1412
https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1412/
op_doi https://doi.org/10.5194/egusphere-2024-1412
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