Arctic soil carbon insulation averts large spring cooling from surface-atmosphere feedbacks

• 成果类型: Article
• 署名作者: Gaillard, Remi; Peylin, Philippe; Cadule, Patricia; Bastrikov, Vladislav; Cheruy, Frederique; Cuynet, Amelie; Ghattas, Josefine; Zhu, Dan; Guenet, Bertrand
• 署名单位: Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Earth Sciences & Astronomy (INSU); Universite PSL; Ecole Normale Superieure (ENS); Universite Paris Saclay; Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); Universite PSL; Ecole Normale Superieure (ENS); Sorbonne Universite; Institut Polytechnique de Paris; Ecole Polytechnique; Universite Paris Saclay; Sorbonne Universite; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Earth Sciences & Astronomy (INSU); Peking University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13392
• DOI: 10.1073/pnas.2410226122
• 发表日期: 2025-01-21
• 关键词: permafrost soils; organic soil; cmip6 models; active-layer; climate; temperature; vegetation; bryophyte

摘要

The insulative properties of soil organic carbon (SOC) and surface organic layers (moss, lichens, litter) regulate surface-atmosphere energy exchanges in the Arctic through a coupling with soil temperatures. However, a physical description of this process is lacking in many climate models, potentially biasing their high-latitude climate predictions. Using a coupled surface-atmosphere model, we identified a strong feedback loop between soil insulation, surface air temperature, and snowfall. Without insulation, the latent heat needed for soil ice thawing leads to a late spring and summer cold bias in surface air temperature (above 2 degrees C) over Arctic regions. The integration of soil insulation eliminates this bias and significantly improves the simulation of permafrost dynamics. Our findings, including the potential consequences of large perturbations (e.g., fires), highlight the importance of combining soil water freezing with a physical representation of SOC and surface organic layer insulation in Earth system models, to improve Arctic climate predictions.