Preprints
https://doi.org/10.5194/egusphere-2024-1412
https://doi.org/10.5194/egusphere-2024-1412
12 Jun 2024
 | 12 Jun 2024
Status: this preprint is open for discussion.

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

Adrien Damseaux, Heidrun Matthes, Victoria R. Dutch, Leanne Wake, and Nick Rutter

Abstract. 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.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Adrien Damseaux, Heidrun Matthes, Victoria R. Dutch, Leanne Wake, and Nick Rutter

Status: open (until 24 Jul 2024)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2024-1412', Anonymous Referee #1, 09 Jul 2024 reply
  • RC2: 'Comment on egusphere-2024-1412', Anonymous Referee #2, 09 Jul 2024 reply
Adrien Damseaux, Heidrun Matthes, Victoria R. Dutch, Leanne Wake, and Nick Rutter
Adrien Damseaux, Heidrun Matthes, Victoria R. Dutch, Leanne Wake, and Nick Rutter

Viewed

Total article views: 280 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
195 66 19 280 14 10
  • HTML: 195
  • PDF: 66
  • XML: 19
  • Total: 280
  • BibTeX: 14
  • EndNote: 10
Views and downloads (calculated since 12 Jun 2024)
Cumulative views and downloads (calculated since 12 Jun 2024)

Viewed (geographical distribution)

Total article views: 264 (including HTML, PDF, and XML) Thereof 264 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 24 Jul 2024
Download
Short summary
Models often underestimate the role of snow cover in permafrost regions, leading to soil temperatures and permafrost dynamics inaccuracies. Through the use of a snow thermal conductivity scheme better adapted to this region, we mitigated soil temperature biases and permafrost extent overestimation within a land surface model. Our study sheds light on the importance of refining snow-related processes in models to enhance our understanding of permafrost dynamics in the context of climate change.