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

BER Research Highlights

New Ground-Truth Solution for Glacier and Ice Sheet Models
Published: August 31, 2015
Posted: December 11, 2015

Glacier and ice sheet models, like other components of the climate system, require simpler and computationally efficient formulations (parameterizations) when implemented into a full global climate model. For ice sheets, a two-dimensional (2D) solution of simplified (low-order) equations is often used. Furthermore, mountain glaciers, generally located in remote and difficult to access regions, are often hard to simulate due to a lack of necessary model input data, most specifically accurate information on glacier geometry. For this reason, it is often convenient to measure glacier geometry only along a central flowline and to model evolution of those glaciers using a 2D flowline model with parameterizations for capturing across-flow geometric effects.

To test the simpler methods, a computationally slow 3D full set of (Stokes) equations is required. The Department of Energy-sponsored Scientific Discovery through Advanced Computing (SciDAC) project Predicting Ice Sheets and Climate Evolution of Extremes (PISCEES) recently published a full-solution result. Researchers systematically studied the applicability of a 2D, first-order Stokes approximation flowline model, modified by geometric shape factors, for the simulation of land-terminating glaciers by comparing it with a 3D, “full”-Stokes ice-flow model. The researchers then explored the sensitivities of the flowline and Stokes models to ice geometry, temperature, and forward model integration time using steady-state and transient, thermomechanically uncoupled and coupled numerical experiments. Their findings show that the 2D, first-order flowline model may produce inaccurate results for (1) steep glaciers with complex basal topography, (2) polythermal glaciers that contain temperate basal ice and experience basal sliding, and (3) coupled thermomechanical glacier evolution over long time periods (~103 years). They conclude that the 2D first-order flowline model should be applied and interpreted with caution when modeling glacier changes under a warming climate or over long periods of time.

Reference: Zhang, T., L. Ju, W. Leng, S. Price, and M. Gunzburger. 2015. “Thermomechanically Coupled Modelling for Land-Terminating Glaciers: A Comparison of Two-Dimensional, First Order and Three-Dimensional, Full-Stokes Approaches,” Journal of Glaciology 61, 702–12. DOI: 10.3189/2015JoG14J220. (Reference link PDF)

Contact: Dorothy Koch, SC-23.1, (301) 903-0105, Randall Laviolette, SC-21, (301) 903-5195
Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Cross-Cutting: Scientific Computing and SciDAC

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)