Earth System Modeling

Earth System Modeling Mission and Priorities

The Earth System Modeling (ESM) Program supports the development of innovative Earth system modeling capabilities, with the ultimate goal of providing accurate and computationally advanced representations of the fully coupled and integrated Earth system, as needed for energy and related sectoral infrastructure planning. Key examples of critical information for energy include accurate projections of water availability, drought incidence and persistence, temperature extremes including prolonged heat stress, probability of storms, opening of the Arctic Ocean, and sea level and storm-surge at coastal regions. In order to provide this information, considerable effort is needed to develop optimal-fidelity climate and Earth system simulations, with suitably-accurate representation of atmospheric dynamics, clouds and chemistry, ocean circulation and biogeochemistry, land biogeochemistry and hydrology, sea-ice and dynamic land-ice, and in each case including elements of human activities that affect these systems such as water management and land-use.

ESM utilizes the mathematical and computational expertise within the DOE-Laboratories to develop efficient, accurate and advanced algorithms for these Earth system processes, and to improve model initialization, optimal component coupling and uncertainty of system simulation and climate projections.  The aim is to optimize the Earth system codes to run efficiently on DOE computers architectures, using modern and sustainable software and workflows, providing the Nation with a high-resolution coupled climate and Earth system simulation capability that is vital for accurately understanding how the climate and earth system evolve and also support DOE responsibilities involving energy planning.

Central to the ESM Program is the Accelerated Climate Modeling for Energy (ACME) project, launched by BER in 2014 to develop a high-resolution Earth system model that efficiently runs at high-resolution on DOE leadership computers, simulating the near-term past (for validation) and future (3-4 decades, to 2050) in support of the DOE science mission. ACME will design and perform high-resolution Earth system simulations, targeting the research community’s more challenging science questions, e.g., involving cloud-aerosol interactions, ice sheet physics, biogeochemistry, hydrology, ocean eddy dynamics, and the interdependence of low frequency variability and extreme weather. Other activities supported by ESM complement and enhance ACME, including the development of potential future-generation ACME capabilities within the Scientific Discovery through Advanced Computing (SciDAC) Program and supporting collaborative and community codes that are developed and used by multiple climate and weather groups.

The ESM Program contributes to the U.S. Global Change Research Program (USGCRP), and coordinates its activities with the climate modeling programs at other federal agencies, particularly the National Science Foundation (NSF) through the CESM project, the National Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics and Space Administration (NASA).

ESM and BER Programmatic Collaborations

ESM supports the development of all essential components of the coupled Earth-human system needed to simulate Earth system and climate by DOE’s research community. Each component (atmosphere, ocean, cryosphere and land) use advanced variable-resolution grids, allowing ultra-high resolution information and process resolution within particular regions of interest. One example is the placement of a very high resolution (e.g. 10 km) atmosphere near the location of a DOE ARM site, in order to overlap the global-model’s cloud-resolving capability with higher-resolution Large-Eddy-Simulations (LES’s) and with the ARM data; this integration of high resolution models with LES and ARM observations serves as a means of studying cloud processes and the coupling with the global system. Another example is the placement of high resolution modeling capabilities in the ocean surrounding Antarctica and along the margins of the Antarctic ice sheet.  Without such high resolution, predictions would be unable to represent many of the critical processes controlling future change, e.g., involving the flow of the ocean up under the ice-sheet, and the dynamics in the ice sheet where the ocean and ice meet. A third example is configuring the land model using basin-gridding instead of rectangular grids in order to effectively study the water flow and supply changes within specific basins.

For global atmospheric models, ESM partners with BER’s Atmospheric System Research (ASR) Program to develop cloud and aerosol parameterizations needed to understand how clouds are shifting and influencing climate sensitivity. The multi-scale Climate Model Development and Validation (CMDV) Program also supports projects that study cloud and aerosol processes, spanning scales from Large-Eddy Simulation (LES) scale to global-model scale, and validating the simulations using Atmospheric Radiation Measurement ARM Facility data as well as other measurements.

For land modeling, ESM collaborates with Terrestrial Ecosystem Science to develop global land model parameterizations, incorporating modeling capabilities that are based on TES field investigations within particular regions. CMDV also supports liaisons that interconnect the modeling activities between ACME and the Next Generation Ecosystem Experiments (NGEE) in the Tropics and the Arctic. These joint efforts are contributing new hydrologic and dynamic ecosystem representations to the ACME model, using validation from field investigations.

ESM and Integrated Assessment Research (IAR) collaborate on the development of coupled human-natural systems, such as understanding how land and water management activities affect the Earth system, as needed for optimal detailed Earth system simulations. An important example is the alignment and coordination between the ACME and the Global Change Assessment Model (GCAM) integrated assessment model. The Integrated Earth System Model project directly coded and coupled the interactions between the climate model CESM and the integrated assessment model GCAM through the terrestrial-carbon cycle. The code from this project will be released to the community in 2017, and will be included in the ACME model for further development.

ESM and Regional and Global Climate Modeling (RGCM) are complementary Programs, with ESM supporting primarily model development, and RGCM focused on model analysis, intercomparison, metrics and validation, as well as using the models to evaluate system sensitivities and feedbacks. Important synergies include high-latitude modeling and research, biogeochemical feedbacks and the international Land Modeling Bencharking (iLAMB) project, use of climate-modeling metrics and diagnostics (e.g. Program for Climate Model Diagnosis and Intercomparison (PCMDI) metrics for ACME), and the use of high-resolution models such as ACME to study extremes.

ESM Computation and Programmatic ASCR and BER Collaborations

Essential to ESM is its collaboration with the Advanced Scientific Computing Research (ASCR) Office, in particular the SciDAC partnership program. SciDAC supports partnership between ASCR and the other Office of Science offices, in order to dramatically accelerate progress in scientific computing. Examples of advances in the BER-ESM-SciDAC projects include the development of: variable-resolution Earth system components, algorithms and mathematical methods to improve efficiency and accuracy of Earth system component simulation on advanced computational architectures, uncertainty characterization of modeling systems, and advances in code performance and portability.

Current BER-ESM-SciDAC projects are developing future capabilities needed in the ACME model, including next-generation dynamic and variable-resolution ice sheet models (Predicting Ice Sheet and Climate Evolution at Extreme Scales (PISCEES)), improved treatments of atmospheric convection and physics, and oceanic eddies that apply across their variable-mesh atmosphere and ocean components (Multiscale Methods for Accurate, Efficient, and Scale-Aware Models of the Earth System), and the next-generation version of ACME atmosphere, which will include non-hydrostatic dynamics, as needed when the model approaches very high-resolution (less than 10km) (A Non-hydrostatic Variable Resolution Atmospheric Model in ACME).

In order for ACME to develop sustainable and portable codes, state-of-science software development methods are important. The Climate Model Development and Validation Program’s ACME-SM: A Global Climate Model Software Modernization Surge is transforming ACME’s atmospheric and coupler codes, introducing new infrastructure capabilities and thorough and improved testing approaches within some of the most critical sub-modules. These developments are expected to be of broad benefit to Earth system as well as other complex, distributed and advanced computational modeling efforts.

Since ACME will be producing very-high resolution, and  high frequency (sub-daily) model output, workflows to manage (download, move, store and analyze) large model outputs are needed. ESM collaborates with BER’s Data Management (DM) on the infrastructure and tools needed for managing large model ouput datasets. The Earth System Grid Federation (ESGF), supported by DM, is critical for hosting and sharing the data generated by ACME and other climate models. ACME’s support of UV-CDAT and similar model analytic tools are also of use to ESGF user communities.

Community Projects Supported by ESM
  • ESM supports many code and component developments that are used by multiple modeling groups, and in some cases supported jointly with other sponsors.
  • The Common Infrastructure for Modeling the Earth (CIME) is jointly developed between ACME and the CESM software engineering groups, to provide various tools and infrastructure for the CESM and ACME models.
  • The sea-ice (CICE) model is a collaborative activity led by scientists at Los Alamos National Laboratory together with scientists from several other climate and operational modeling centers and groups.
  • Ultrascale Visualization (UV-CDAT) is a software package for analysis, visualization and management of Earth system model output. It is part of the ACME project, but is used broadly and co-sponsored by NASA as well as DOE.
  • The Functionally Assembled Terrestrial Ecosystem Simulator (FATES) is a tropical ecosystem model under development as part of the Terrestrial Ecosystem Sciences (TES) Next Generation Ecosystem Experiment (NGEE) – Tropics and is co-supported by ESM.
  • The MARBL: Marine Biogeochemistry Library (led by Long, NCAR) is developing a modular ocean biogeochemistry (BGC) capability for use in both ACME and the Community Earth System Model (CESM), and to include options of BGC complexity as needed for a range of research projects.
  • The Community Emissions Data System (CEDS) (led by Smith, PNNL) is establishing a comprehensive emissions database for Earth system models, with a focus on short-lived species such as aerosols and ozone precursors, with the emissions subdivided by processes in a manner that will allow evaluation of emissions uncertainty.
  • The Cloud Layers Unified by Binormals (CLUBB) is a cloud and turbulence parameterization used in the ACME model as well as other Earth system models, and has been supported by NSF and NOAA as well as DOE.
Examples of Additional Projects Supported by ESM

Recent Content

Recent Highlights

Large-scale climate models run for months to understand climate changes over the course of decades. This process creates volumes of data with both high temporal and spatial resolution information. This paper proposes an effective online data monitoring and saving strategy with the consideration of...
A global sensitivity analysis (GSA) was performed using a new methodology on the Energy Exascale Earth System (E3SM) v1 land model that indicates the key parameters driving uncertainty in model projections of carbon and energy-related outputs.  The GSA was performed across 96 sites representing a...
The DOE Energy Exascale Earth System Model (E3SM) project is developing a new non-hydrostatic dynamical core for modeling atmospheric fluid dynamics at high resolution. This work canvassed over 250 integration methods and solvers to determine the most promising approaches for the new dynamical core...
Land cover conversion uncertainty constitutes a 5 ppmv range in estimated 2004 atmospheric CO2 concentration, a range of 2004 terrestrial carbon stock uncertainty that is 80% of net historical CO2 and climate effects on this stock, and over 1 °C range in local surface temperature estimates (1984-...
A comprehensive investigation was performed of how the variable-resolution CESM simulates the Rocky Mountain region when compared with uniform-resolution simulations, observations, and a regional model (CRCM5). This study focused on topographically-sensitive quantities, particularly mountain...

Publications

Large-scale climate simulation models have been developed and widely used to generate historical data and study future climate scenarios. These simulation models often have to run for a couple of months to understand the changes in the global climate over the course of decades. This long-duration...
We conduct a global sensitivity analysis (GSA) of the Energy Exascale Earth System Model (E3SM), land model (ELM) to calculate the sensitivity of five key carbon cycle outputs to 68 model parameters. This GSA is conducted by first constructing a Polynomial Chaos (PC) surrogate via new Weighted...
The efficient simulation of non-hydrostatic atmospheric dynamics requires time integration methods capable of overcoming the explicit stability constraints on time step size arising from acoustic waves. In this work, we investigate various implicit-explicit (IMEX) additive Runge-Kutta (ARK) methods...
Previous studies have examined land use change as a driver of global change, but the translation of land use change into land cover conversion has been largely unconstrained. Here we quantify the effects of land cover conversion uncertainty on the global carbon and climate system using the...
The reliability of climate simulations and projections, particularly in the regions with complex terrains, is greatly limited by the model resolution. In this study, we evaluate the variable-resolution Community Earth System Model (VR-CESM) with a high-resolution (0.125 deg) refinement over the...

Projects

One of the DOE Exascale Computing Project Applications
The Flows of Agricultural Nitrogen (FAN) parameterization for the emissions of nitrogen has been augmented to better account for the flows of manure directly onto pastures, or through animal housing facilities and storage facilities onto agricultural fields and pastures. Following the improvement...