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

BER Research Highlights


Microtopography Determines Active Layer Depths and Responses to Temperature and Precipitation at the NGEE-Arctic’ Barrow Experimental Observatory sites
Published: December 20, 2017
Posted: January 23, 2018

Landscape features determine thermal and hydrological responses in polygonal tundra.

The Science
A research team from Lawrence Berkeley Laboratory applied a well-tested three-dimensional coupled biogeochemistry, hydrology, vegetation, and thermal model, called ecosys, to polygonal tundra sites in Alaska to quantify and scale the effects of microtopography on Active Layer Depth (ALD), soil hydrology, and energy exchanges with the atmosphere. They found that interannual variation in ALD was more strongly related to precipitation than air temperature, contrary to what most large-scale models assume. Further, they found excellent spatial scaling results from sub-meter to landscape scales using our modeling approach.

The Impact
The LBNL team demonstrated excellent agreement between predictions and NGEE-Arctic observations of soil temperature and moisture and eddy covariance energy exchanges with the atmosphere. The estimates of the importance of precipitation energy content on thaw depth have important implications for predictions of future thermal, hydrological, and biogeochemical states in the Arctic. Finally, these results imply needed improvements to the DOE E3SM land model (ELMv1-ECA).

Summary
Current ESM land model representations of high-latitude thermal and hydrological states ignore several important processes and representation of sub-grid scale heterogeneity, and therefore predicted interactions with the atmosphere remain uncertain. The LBNL analysis here, which combined fine-scale modeling and comparison to a wide range of NGEE-Arctic measurements, demonstrates a viable approach to representing fine-scale processes and links to landscape scale dynamics. Together these findings challenge widely held assumptions about controls on landscape-scale energy and water budgets, and are motivating their ongoing improvements to the DOE land model (ELMv1-ECA).

PM Contacts
Daniel Stover
SC-23.1
Daniel.Stover@science.doe.gov (301-903-0289)

PI Contact
William J. Riley
Lawrence Berkeley National Laboratory
wjriley@lbl.gov

Funding
This research was supported by the Director, Office of Science, Office of Biological and Environmental Research of the US Department of Energy under Contract No. DE-AC02-05CH11231 as part of the Next-Generation Ecosystem Experiments (NGEE Arctic) project.

Publications
Grant, R.F., Z.A. Mekonnen, W.J. Riley, H.M. Wainwright, D.E. Graham, and M.S. Torn.  “Mathematical Modelling of Arctic Polygonal Tundra with Ecosys: 1. Microtopography Determines How Active Layer Depths Respond to Changes in Temperature and Precipitation.” JGR-Biogeosciences, 122(12), 3161-3173 (2017). [DOI: 10.1002/2017JG004035]

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • 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

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)