| Titre | Evaluating permafrost physics in the Coupled Model Intercomparison Project 6 (CMIP6) models and their sensitivity to climate change |
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| Auteur | Burke, E J; Zhang, Y ; Krinner, G |
| Source | The Cryosphere vol. 14, issue 9, 2020 p. 3155-3174, https://doi.org/10.5194/tc-14-3155-2020  Accès ouvert |
| Image |  |
| Année | 2020 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20200508 |
| Éditeur | Copernicus GmbH |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.5194/tc-14-3155-2020 |
| Media | papier; en ligne; numérique |
| Formats | pdf; html |
| Sujets | pergélisol; effets climatiques; climat arctique; temperature; établissement de modèles; modèles; profils pédologiques; sensitivité de terrain; Changement climatique; dégel du pergélisol; géologie des
dépôts meubles/géomorphologie; pédologie; géologie de l'environnement; Nature et environnement; Sciences et technologie |
| Illustrations | coupes schématiques transversales; tableaux; graphiques; graphique à barres; croquis cartographiques; modèles |
| Programme | Centre canadien de télédétection Méthodes et applications optiques |
| Diffusé | 2020 09 16 |
| Résumé | (disponible en anglais seulement)
Permafrost is a ubiquitous phenomenon in the Arctic. Its future evolution is likely to control changes in northern high-latitude hydrology and biogeochemistry.
Here we evaluate the permafrost dynamics in the global models participating in the Coupled Model Intercomparison Project (present generation - CMIP6; previous generation - CMIP5) along with the sensitivity of permafrost to climate change. Whilst the
northern high-latitude air temperatures are relatively well simulated by the climate models, they do introduce a bias into any subsequent model estimate of permafrost. Therefore evaluation metrics are defined in relation to the air temperature. This
paper shows that the climate, snow and permafrost physics of the CMIP6 multi-model ensemble is very similar to that of the CMIP5 multi-model ensemble. The main differences are that a small number of models have demonstrably better snow insulation in
CMIP6 than in CMIP5 and a small number have a deeper soil profile. These changes lead to a small overall improvement in the representation of the permafrost extent. There is little improvement in the simulation of maximum summer thaw depth between
CMIP5 and CMIP6. We suggest that more models should include a better-resolved and deeper soil profile as a first step towards addressing this. We use the annual mean thawed volume of the top 2m of the soil defined from the model soil profiles for the
permafrost region to quantify changes in permafrost dynamics. The CMIP6 models project that the annual mean frozen volume in the top 2m of the soil could decrease by 10 %-40%C1 of global mean surface air temperature increase. |
| GEOSCAN ID | 327428 |
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