Unfrozen Permafrost Presence in Shrub-Dominated Landscapes

Unfrozen Permafrost Presence in Shrub-Dominated Landscapes

November 27th, 2019
Field observations and model simulations confirm the presence of unfrozen permafrost in shrub-dominated landscapes.
The Objective: 
  • Couple surface and subsurface thermal-hydrology in permafrost landscapes and simulate the timing and magnitude of talik formation associated with shrubs and snow.
New Science: 
  • Shrubs, especially tall shrubs, trap snow and provide an insulating layer that keeps ground warmer than the surrounding landscape.
  • Increases in groundwater discharge due to talik formation can contribute to the observed increases in Arctic river discharge during the winter and spring snowmelt period.
The Impact: 
  • Numerical experiments explain that the transition from continuous to discontinuous permafrost can happen quickly, and create new pathways for water flow in hillslope environments.

Schematic of modeling transect showing simulated formation of talik (e.g., unfrozen soil) beneath shrubs that capture snow, and hence influence ground thermal regime during the winter.