U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


Arctic Greening Thaws Permafrost, Boosts Groundwater Flow
Published: October 15, 2018
Posted: April 22, 2019

Models are used to understand how low-Arctic landscapes are changing in a warming climate.

The Science
Models of permafrost dynamics were used to show that snow drifts associated with tall shrub patches warm the underlying soil, resulting in holes called “through taliks” in the permafrost. Through taliks can activate deep flow pathways that significantly alter groundwater flow patterns in shrub-tundra landscapes.

The Impact
The resulting increases in groundwater discharge suggest that observed increases in tall shrub abundance throughout the Arctic may be a driver of observed increases in winter Arctic river discharge.

Summary
At hilly field sites in the southern Seward Peninsula, AK, patches of deep snow in tall shrubs are associated with higher winter ground temperatures. Researchers from the NGEE-Arctic study show that through taliks—thawed zones extending through the entire permafrost layer— can form under these patches. The formation of through taliks creates new hydrologic pathways connecting the near surface to deeper regions, with significant hydrological and biogeochemical consequences. In particular, through taliks enable exchange and transport of nutrients and soil carbon from shallow upland hillslope sources to streams and lakes through groundwater discharge. To better understand the processes controlling and consequences of through taliks, they used NGEE-Arctic’s permafrost hydrology model, ATS, to simulate through taliks associated with snow drifts. Scenarios were developed based on an intensively studied hillslope transect on the southern Seward Peninsula. In these scenarios, when through taliks formed, sub-permafrost groundwater flow greatly increased. The simulations showed that through talik can form quickly (over a few decades) and then drive a rapid increase in sub-permafrost groundwater.

Contacts (BER PM)
Daniel Stover
SC-23.1
Terrestrial Ecosystem Science
Daniel.Stover@science.doe.gov

Elchin Jafarov
Los Alamos National Laboratory
elchin@lanl.gov

Ethan Coon
Oak Ridge National Laboratory
coonet@ornl.gov

Funding
This work is part of the Next Generation Ecosystem Experiments (NGEE) Arctic project which is supported by the Office of Biological and Environmental Research in the DOE Office of Science.

Publications
Jafarov, E.E., E.T. Coon, D.R. Harp, C.J. Wilson, S.L. Painter, A.L. Atchley, & V.E. Romanovsky. “Modeling the role of preferential snow accumulation in through talik development and hillslope groundwater flow in a transitional permafrost landscape.” Environmental Research Letters 13, 105006 (2018). [DOI:10.1088/1748-9326/aadd30]

Related Links
NGEE Arctic

Topic Areas:

  • Research Area: Terrestrial Ecosystem Science
  • Research Area: Next-Generation Ecosystem Experiments (NGEE)

Division: SC-23.1 Climate and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)