Biogeophysical controls on soil-atmosphere thermal differences: implications on warming Arctic ecosystems

Juha Aalto, Daniel Scherrer, Jonathan Lenoir, Antoine Guisan, Miska Luoto

Research output: Contribution to journalLetterScientificpeer-review


Soil temperature (ST) has a key role in Arctic ecosystem functioning and global environmental change. However, soil thermal conditions do not necessarily follow synoptic temperature variations. This is because local biogeophysical processes can lead to a pronounced soil-atmosphere thermal offset (Delta T) while altering the coupling (beta Tau) between ST and ambient air temperature (AAT). Here, we aim to uncover the spatiotemporal variation in these parameters and identify their main environmental drivers. By deploying a unique network of 322 temperature loggers and surveying biogeophysical processes across an Arctic landscape, we found that the spatial variation in Delta T during the AAT 0 period, Delta T was controlled by soil characteristics, vegetation and solar radiation (Delta T = -0.6 degrees C +/- 1.0 degrees C). Importantly, Delta T was not constant throughout the seasons reflecting the influence of beta Tau on the rate of local soil warming being stronger after (mean beta Tau = 0.8 +/- 0.1) than before (beta Tau = 0.2 +/- 0.2) snowmelt. Our results highlight the need for continuous microclimatic and local environmental monitoring, and suggest a potential for large buffering and non-uniform warming of snow-dominated Arctic ecosystems under projected temperature increase.
Original languageEnglish
Article number074003
JournalEnvironmental Research Letters
Issue number7
Number of pages11
Publication statusPublished - 26 Jun 2018
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1172 Environmental sciences
  • thermal variability
  • microclimate
  • soil-atmosphere decoupling
  • soil temperature
  • structural equation model
  • snow cover
  • offset
  • SNOW
  • AIR

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