Earth System Model Development

Mission and Priorities

The Earth System Model Development program area supports innovative and computationally advanced 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. To provide this information, considerable effort is needed to develop optimal-fidelity 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.

Earth System Model Development utilizes the mathematical and computational expertise within the DOE national 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 computer architectures, using modern and sustainable software and workflows, providing a high-resolution coupled climate and earth system simulation capability that is vital for accurately understanding how the earth system evolve and also support DOE energy planning responsibilities.

Central to the Earth System Model Development activities is the Energy Exascale Earth System Model (E3SM) project, which is developing an earth system model that efficiently runs at high-resolution on DOE high-performance computers, simulating the near-term past (for model validation) and future (3 to 4 decades) in support of the DOE science mission. E3SM 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 Earth System Model Development complement and enhance E3SM, including the development of potential future-generation 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 Earth System Model Development program area contributes to the U.S. Global Change Research Program (USGCRP), and coordinates its activities with the climate modeling programs at other federal agencies, particularly National Science Foundation (NSF) through the CESM project, National Oceanic and Atmospheric Administration (NOAA), and National Aeronautics and Space Administration (NASA).

Programmatic Collaborations

The Earth System Model Development program area 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) uses 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 Atmospheric Radiation Measurement (ARM) user facility observatory, in order to overlap the global model’s cloud-resolving capability with higher-resolution large-eddy simulations (LES’s) and with 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 ice sheets, and the dynamics where the ocean and ice sheets meet. A third example is configuring the land model using basin-gridding instead of rectangular grids to effectively study the water flow and supply changes within specific basins.

For global atmospheric models, 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 multiscale 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) user facility data, as well as other measurements.

For land modeling, this program area collaborates with Terrestrial Ecosystem Science (TES) 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 E3SM 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 E3SM model, using validation from field investigations.

The Earth System Model Development and Multisector Dynamics program areas ollaborate on the development of coupled human-natural systems, such as understanding how land and water management activities affect the Earth's system, as needed for optimal detailed earth system simulations. An important example is the alignment and coordination between E3SM and 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.

Earth System Model Development and Regional and Global Model Analysis (RGMA) are complementary programs, with Earth System Model Development supporting primarily model development, and RGMA 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 Benchmarking (iLAMB) project, use of climate-modeling metrics and diagnostics (e.g., Program for Climate Model Diagnosis and Intercomparison (PCMDI) metrics for E3SM), and the use of high-resolution models such as E3SM to study extremes.

Computation and Programmatic ASCR and BER Collaborations

Essential to Earth System Model Development activities 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-Model Development and 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 joint projects with SciDAC include developing future capabilities needed in the E3SM, originally known as the Accelerated Climate Modeling for Energy (ACME) model, such as 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 E3SM 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 E3SM 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 E3SM 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's system as well as other complex, distributed, and advanced computational modeling efforts.

Since E3SM 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. Earth System Model Development collaborates with BER’s Data Management (DM) on the infrastructure and tools needed for managing large model output data sets. The Earth System Grid Federation (ESGF), supported by DM, is critical for hosting and sharing the data generated by E3SM and other climate models. E3SM’s support of UV-CDAT and similar model analytic tools are also of use to ESGF user communities.

Community Projects Supported by Earth System Model Development

The Earth System Model Development program area supports many code and component developments that are used by multiple modeling groups, and in some cases, supported jointly with other sponsors.

  • Common Infrastructure for Modeling the Earth (CIME) is jointly developed between E3SM and the CESM software engineering groups to provide various tools and infrastructure for the CESM and E3SM 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 E3SM project, but is used broadly and co-sponsored by NASA as well as DOE.
  • 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 Earth System Model Development.
  • MARBL: Marine Biogeochemistry Library is developing a modular ocean biogeochemistry (BGC) capability for use in both E3SM and CESM and to include options of BGC complexity as needed for a range of research projects.
  • Community Emissions Data System (CEDS) 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.
  • Cloud Layers Unified by Binormals (CLUBB) is a cloud and turbulence parameterization used in the E3SM 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 Earth System Model Development

Recent Content

Current Projects

We have modified the source spectrum parameterization of convectively generated gravity waves and have significantly improved the representation of the quasi-biennial oscillation (QBO) in the lower tropical stratosphere. 
This project has just been awarded recently. We have modified the E3SM code to include cloud longwave scattering. Currently, we are testing the code for this modification. 
The primary objective of this renewal project is to complete a study that evaluates the relative merits of two approaches used to initialize fine resolution present day transient climate model simulations representing the latter half of the 20th century. Unlike standard climate models, the...
One of the DOE Exascale Computing Project Applications

Recent Highlights

ELM v1 is able to capture the observed west-to-east gradient of productivity and biomass because of the introduction of phosphorus (P) cycle dynamics and soil order-based tree mortality. Our model simulations show that the consideration of P availability leads to a smaller carbon sink associated...
A locally conservative transport scheme is designed for next-generation computing platforms.
Earth system models, including E3SM, have long standing problems representing deforestation effects on evapotranspiration, which is problematic when the models are used for forest and water resources management decisions. We optimized the E3SM Land Model (ELMv1) to match observations from a recent...
Snow has the highest albedo of all natural surfaces on Earth; an accurate simulation of the shortwave radiative properties of snowpack is therefore crucial for spectrally partitioning solar energy and representing snow-albedo feedbacks across the Earth system. E3SM inherited two different radiative...
Terrestrial ecosystem carbon (C), nitrogen (N), and phosphorus (P) cycling processes are strongly modulated by the climate and they also generate significant feedbacks to the climate system and play important roles in the changing climate.
Global ecosystem models currently predict that the Amazon rainforest will continue to act as a carbon sink in the future due to rising atmospheric carbon dioxide (CO2) concentrations, effectively enhancing ecosystem resilience and reducing the pace of climate change. However, the uncertainty of...
Trend, detection, and attribution analyses were performed using naturalized streamflow observations and routed land surface model runoff for 10 subbasins in the Columbia River Basin (CRB) during water years 1951–2008. 
In some regions of Earth's oceans, warm, relatively fresh surface waters are separated from cold deep water by a layer of warm but relatively salty water - termed a barrier layer. This work, focussing on E3SM, is the first global assessment of barrier layers in Earth system models. Causes and...
The role of phosphorus availability has not been considered in any of the CMIP5 models. This study shows that phosphorus availability could greatly reduce the projected CO2-induced carbon sink in Amazon rainforests. This study suggests that the Amazon rainforest responses to increasing atmospheric...
Algorithms and software were developed to solve a key challenge, property preservation, in modeling atmospheric transport of trace constituent species, such as water vapor, trace gases, and aerosols. These methods will speed up global climate models.

Recent Publications

Tropical forests play a crucial role in the global carbon cycle, accounting for one-third of the global NPP and containing about 25% of global vegetation biomass and soil carbon. This is particularly true for tropical forests in the Amazon region, as these comprise approximately 50% of the world’s...
A set of algorithms based on characteristic discontinuous Galerkin methods is presented for tracer transport on the sphere. The algorithms are designed to reduce MPI communication volume per unit of simulated time relative to current methods generally and to the spectral element scheme employed by...
Evapotranspiration (ET) plays an important role in land‐atmosphere coupling of energy, water, and carbon cycles. Following deforestation, ET is typically observed to decrease substantially as a consequence of decreases in leaf area and roots and increases in runoff. Changes in ET (latent heat flux...
Snow is an important climate regulator because it greatly increases the surface albedo of middle and high latitudes of the Earth. Earth system models (ESMs) often adopt two-stream approximations with different radiative transfer techniques, the same snow therefore has different solar radiative...
Over the past several decades, the land modeling community has recognized the importance of nutrient regulation on the global terrestrial carbon cycle. Implementations of nutrient limitation in land models are diverse, varying from applying simple empirical down‐regulation of potential gross...
Global terrestrial models currently predict that the Amazon rainforest will continue to act as a carbon sink in the future, primarily owing to the rising atmospheric carbon dioxide (CO2) concentration. Soil phosphorus impoverishment in parts of the Amazon basin largely controls its functioning, but...
Trend, detection, and attribution analyses were performed using naturalized streamflow observations and routed land surface model runoff for 10 subbasins in the Columbia River Basin (CRB) during water years 1951–2008. The Energy Exascale Earth System land-surface model (ELM) version 1.0 and the...
Ocean barrier layers (BLs) separate the mixed layer from the top of the thermocline, and are able to insulate the mixed layer from entrainment of cold thermocline water. Here, we provide the first global BL assessment in E3SMv1 and two other earth system models. Compared to observations, models...
Urban heat island (UHI), the phenomenon that urban areas experience higher temperatures compared to their surrounding rural areas, has significant socioeconomic and environmental impacts. With current and anticipated rapid urbanization, improved understanding of the response of UHI to urbanization...
Global terrestrial models currently predict that the Amazon rainforest will continue to act as a carbon sink in the future, primarily owing to the rising atmospheric carbon dioxide (CO2) concentration. Soil phosphorus impoverishment in parts of the Amazon basin largely controls its functioning, but...