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A new Earth modeling system will support weather-scale resolution and use advanced computers to simulate aspects of Earth’s variability and anticipate decadal changes that will impact the U.S. energy sector in the coming years. future. After four years of development, the Energy Exascale Earth System Model (E3SM) is published to the entire scientific community this month.

The E3SM project is supported by the Office of Science, Department of Energy, Office of Biological and Environmental Research. The E3SM release will include model code and documentation, as well as results from an initial set of benchmark simulations.

The E3SM high-resolution Earth system model simulates the strongest storms with surface winds exceeding 150 mph – hurricanes that leave cold wakes 2 to 4 degrees Celsius colder than their surroundings. This simulation depicts how sea surface temperature changes evolve as a hurricane (seen here approaching the east coast of the United States) moves across the Atlantic and how the resulting cold wake affects the subsequent intensification of the next hurricane. Source: LLNL. Click to enlarge.

Over the past three years, E3SM Phase I has developed the first version (v1) of the E3SM model. Phase II expands and expands this work by further exercising the low and high resolution versions of v1, adding available enhancements and exercising the model with regional refinement over North America for v2, and significantly improving the model performance, infrastructure and phase II earth system capabilities by developing v3-v4 (for use in a phase III simulation campaign).

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Three new model components are included in the E3SM v1 configuration: Ocean All Scale Forecast Model (MPAS), Sea Ice MPAS and Land Ice MPAS. Pictured, the E3SM global simulation shows eddy activity. Source: E3SM. Click to enlarge.

Phase II will continue to push the limits in terms of model resolution beyond the current hydrostatic limit in the atmosphere. During this period, the coupled system will run efficiently on the most powerful computers in the DOE High Performance Computational Facility.

The E3SM project will soon be converted into an “open development” project. This means that not only the released version 1 code, but also the code in development, will be visible to those interested in the continued evolution of the code. This conversion to open code will allow collaboration with more groups and centers.

Earth, with its myriad interactions between atmosphere, oceans, land and ice components, presents an extraordinarily complex system for investigation. Earth system simulation involves solving approximations of physical, chemical, and biological governing equations on spatial grids at as fine resolutions as computing resources permit.

The goal of the E3SM project is to reliably simulate aspects of Earth system variability and predict decadal changes that will critically impact the US energy sector in the near future. These critical factors include a) regional air/water temperatures, which can strain energy networks; (b) water availability, which affects power plant operations; c) extreme water cycle events (eg floods and droughts), which impact infrastructure and bioenergy; and (d) sea level rise and coastal flooding, which threaten coastal infrastructure.

The project is developing an Earth System Model (ESM) that has not been possible due to the limitations of current computing technologies. Achieving this goal will require advances on three fronts: 1) better resolution of Earth system processes through a strategic combination of development of new processes in the model, increased model resolution, and improved computational performance; 2) more realistically represent the two-way interactions between human activities and natural processes, especially when these interactions affect US energy needs; and 3) ensemble modeling to quantify the uncertainty of model simulations and projections.

The quality and quantity of observations really force us to constrain the models. With the new system, we will be able to more realistically simulate the present, giving us more confidence to simulate the future.

—David Bader, Lawrence Livermore National Laboratory (LLNL) scientist and E3SM project manager

Simulating atmospheric and oceanic fluid dynamics with fine spatial resolution is particularly challenging for ESMs.

The E3SM project positions itself at the forefront of this research challenge, acting on behalf of an international ESM effort. Increasing the number of simulated Earth system days per day of computation time is a prerequisite for achieving the goal of the E3SM project. It is also important for E3SM to make effective use of the various computing architectures that the DOE’s Office of Advanced Scientific Computing Research (ASCR) procures to prepare for the uncertain future of next-generation machines.

A long-term goal of the E3SM project is to use exascale machines that will be acquired over the next five years. The development of the E3SM continues in parallel with the Exascale Computing Initiative (ECI). This represents a thousandfold increase in performance compared to the most advanced computers of ten years ago.

This model adds a much more complete representation between the interactions of the energy system and the earth system. The increased computing power allows us to add more detail to processes and interactions, resulting in more accurate and useful simulations than previous models.

—David Bader

To address the various critical factors impacting the energy sector in the United States, the E3SM project is dedicated to answering three overarching scientific questions that drive its digital experimentation initiatives:

  • Water cycle: How does the hydrological cycle interact with the rest of the human-earth system at local to global scales to determine water availability and water cycle extremes?

  • Biogeochemistry: How do biogeochemical cycles interact with other components of the Earth system to influence the energy sector?

  • Cryosphere systems: How do rapid changes in cryosphere systems (continental and ocean ice) evolve with the Earth system and contribute to sea level rise and increased coastal vulnerability?

In the E3SM, all model components (atmosphere, ocean, land, ice) can use variable resolution to focus computing power on small-scale processes in regions of particular interest. This is implemented using advanced mesh designs that smoothly shrink the scale of the grid from the coarsest outer region to the finest region.

The E3SM project includes more than 100 scientists and software engineers in several DOE laboratories as well as several universities; DOE laboratories include Argonne, Brookhaven(link is external), LLNL, Lawrence Berkeley, Los Alamos, Oak Ridge, Pacific Northwest, and Sandia National Laboratories. In recognition of uniting the DOE’s Earth System Modeling community to perform high-resolution coupled simulations, the E3SM Executive Committee received the Secretary of Energy’s Award of Excellence in 2015.

In addition, the E3SM project benefits from DOE programmatic collaborations, including the Exascale Computing(link is external) (ECP) project and programs in Scientific Discovery through Advanced Computing (SciDAC), Climate Model Development and Validation (CMDV). ), measurement of atmospheric radiation (ARM), Program for Climate Model Diagnosis and Intercomparison (PCMDI), International Land Model Benchmarking Project (iLAMB), Community Earth System Model Community Earth System Model (CESM) and Next Generation Ecosystem Experiments (NGEE) for the Arctic and the Tropics.