The Science

Researchers developed and demonstrated a new process-rich simulation capability for coupled surface and subsurface thermal hydrology in permafrost regions. The Arctic Terrestrial Simulator (ATS) represents nonisothermal surface flow, subsurface thermal hydrology, phase change, surface energy balance, and snow distribution in fully coupled three-dimensional (3D) simulations.

The Impact

Existing permafrost thermal hydrology simulation tools are limited in their capability to represent the thermal effects of surface and subsurface flows and other important thermal processes. This new process-rich, fine-scale model dramatically expands the range of permafrost thermal hydrology phenomena that can be represented in simulations and provides a community modeling tool to help advance process understanding and evaluate approximations used in Earth system models.

Summary

ATS is a collection of physics modules and physics-informed model couplers for use in a parallel, open-source subsurface flow and transport simulator called Amanzi-ATS. A team of researchers developed new models for nonisothermal overland flow and snow distribution in microtopography, new approaches for robustly coupling 2D surface and 3D subsurface models, and new strategies for managing complexity in process-rich simulations. They combined those new capabilities with a state-of-the-art model for thermal hydrology of freezing and thawing soil. Fine-scale, 100-year projections of the integrated permafrost thermal hydrological system in polygonal tundra near Barrow, Alaska, demonstrate the feasibility of microtopography-resolving, process-rich simulations as a tool to help understand possible future evolution of the carbon-rich Arctic tundra in a warming climate.

Principal Investigator

Scott Painter
Oak Ridge National Laboratory
paintersl@ornl.gov

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

This work was supported by the Next-Generation Ecosystem Experiments (NGEE)–Arctic project. NGEE-Arctic is supported by the Office of Biological and Environmental Research within the U.S. Department of Energy Office of Science.

References