Self-Amplifying Feedbacks Accelerate Greening and Warming of the Arctic

Journal Article · 20 July 2018 · Geophysical Research Letters

DOI: https://doi.org/10.1029/2018GL077830 · OSTI ID:1463985

Zhang, W.  ^[1]; Miller, P. A.  ^[2]; Jansson, C. ^[3]; Samuelsson, P. ^[3]; Mao, J.  ^[4]; Smith, B.  ^[2]

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1. Department of Physical Geography and Ecosystem Science, Lund University, Lund Sweden; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen Denmark
2. Department of Physical Geography and Ecosystem Science, Lund University, Lund Sweden
3. Rossby Centre, Swedish Meteorological and Hydrological Institute, Norrköping Sweden
4. Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge TN USA

Increased greening, higher vegetation productivity, and shrubification have been observed in Arctic tundra in response to recent warming. Such changes have affected the near-surface climate through opposing biogeophysical feedbacks (BF) associated with changes to albedo and evapotranspiration. However, the likely spatiotemporal variations of BF to future climate change and the consequences for Arctic vegetation and ecology have not been robustly quantified. In this paper, we apply a regional Earth system model (RCA-GUESS) interactively coupling atmospheric dynamics to land vegetation response in three potential 21st-century radiative forcing simulations for the Arctic. We find that BF, dominated by albedo-mediated warming in early spring and evapotranspiration-mediated cooling in summer, have the potential to amplify or modulate local warming and enhance summer precipitation over land. Finally, the magnitude of these effects depends on radiative forcing and subsequent ecosystem responses. Thus, it is important to account for BF when assessing future Arctic climate change and its ecosystem impacts.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); Swedish Research Council (VR)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1463985
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 14 Vol. 45; ISSN 0094-8276
• Publisher: American Geophysical UnionCopyright Statement
• Country of Publication: United States
• Language: English