• February 3, 2019
  • Feature Story,Home Page Feature
  • Extreme rainfall in Asia.

    Thirteen new research projects to use or develop the Energy Exascale Earth System Model (E3SM, received a cumulative total of $10 million in funding in 2018.

    Several projects focus on improving the representation of oceans, atmosphere, and clouds in versions 2 and 3 of the model. Others will use version 1 to conduct model analysis of processes, such as extreme weather events. Some projects analyze E3SM in light of the way other major models simulate certain processes and events. More than half the projects aim to reduce biases thereby improving E3SM and helping to expose other factors that continue to contribute to model bias which can be further addressed in future versions.

    The current analysis and development projects were chosen by competitive peer review under one U.S. Department of Energy (DOE) Funding Opportunity Announcement within the Office of Biological and Environmental Research of the Department’s Office of Science. The funded projects include:

    • Parameterizing the Impact of Mesoscale Eddies on Earth System Processes in the Energy Exascale Earth System Model,” led by Anand Gnanadesikan at Johns Hopkins University, is investigating and improving the lateral mixing parameterization in the ocean component of E3SM thereby improving the representation of nutrient cycles, chlorophyll, global overturning, sea-surface tem­­peratures and ­modes of variability, such as the El Niño Southern Oscillation (ENSO).
    • The Multi-Plume Eddy-Diffusivity/Mass-Flux (EDMF) Unified Parameterization: Stratocumulus and the Transition to Cumulus Boundary Layers,” led by Joao Teixeira at the University of California at Los Angeles (UCLA), is implementing a new cloud physics scheme, the Eddy Diffusivity Mass Flux (EDMF) scheme, to reduce deficiencies and biases in modeling stratocumulus and cumulus clouds, enabling better representation of the transition from stratocumulus to cumulus clouds—a key feature in capturing realistic cloud-climate feedbacks.
    • Improving Momentum Transport Processes in E3SM,” led by Jadwiga H. Richter at the National Center for Atmospheric Research (NCAR), is improving the subgrid representation of momentum transport in the atmosphere, which affects global circulation, precipitation patterns, and organized modes of variability, such as the El Niño Southern Oscillation (ENSO), thereby decreasing model biases.
    • Incorporate More Realistic Surface-Atmosphere Radiative Coupling in E3SM,” led by Xianglei Huang at the University of Michigan, is improving how longwave radiation is handled in the model – specifically the longwave land emissivity and scattering effects of ice-phase clouds – to simulate real-world conditions, especially important at the high-latitudes.
    • Enhancing Convection Parameterization for Next Generation E3SM”, led by Guang Zhang at Scripps Institution of Oceanography, is improving the representation of convective processes by adding stochasticity and improved microphysics to reduce biases in precipitation, then testing the improvements with Cloud-Associated Parameterization Testbed (CAPT)-generated hindcasts and comparing the model with ARM observational data.

      Transition from stratocumulus to cumulus clouds over the Eastern North Atlantic ARM site.

    • Collaborative Project: Developing Coupled Data Assimilation Strategy,” led by Zhengyu Liu at Ohio State University, is developing a computationally-efficient ensemble coupled data assimilation (ECDA) system to initialize the coupled model and to understand model biases.
    • Simulating Extreme Precipitation in the United States in the Energy Exascale Earth System Model: Investigating the importance of Representing Convective Intensity Versus Dynamic Structure,” led by Gabriel J Kooperman at the University of Georgia, is evaluating the tradeoffs between resolving the convective scale processes that control the intensity of extreme precipitation events versus large-scale processes that control the dynamic structure of these events, using two versions of E3SM, superparameterized and high-resolution, each constrained to similar computational costs. The results will indicate whether extreme weather events are better simulated by resolving the convective intensity or focusing on the dynamic structure.
    • Monsoon Extremes: Impacts, Metrics, and Synoptic-Scale Drivers,” led by William Boos at the University of California, Berkeley, is enhancing understanding of the physical processes responsible for variations in extreme rainfall in monsoonal regions by examining synoptic-scale systems embedded in larger-scale monsoons and focusing on synoptic (2-12 day) time scales. The project uses the High-Resolution E3SM as well as models in the High-Resolution Model Intercomparison Project (HighResMIP) and includes characterization of E3SM model bias in simulating the full rainfall distribution and the creation of dynamically-based metrics for extreme monsoonal rainfall.
    • Madden-Julian Oscillation, Tropical Cyclones, and Precipitation Extremes in E3SM,” led by Daehyun Kim at the University of Washington, is diagnosing process-level errors in the representation of the Madden-Julian Oscillation (MJO), tropical cyclones, and precipitation extremes in E3SM and other earth system models to recommend improvements for the next generation of models to reduce bias for these phenomena.
    • The Atlantic Multidecadal Oscillation: Key Drivers and Climate Impacts,” led by Young-Oh Kwon at Woods Hole Oceanographic Institution, is using hierarchical modeling to advance process-level understanding of two key drivers of the Atlantic Multidecadal Oscillation (AMO): the ocean circulation associated with the Atlantic meridional overturning circulation and random atmospheric noise, which is primarily due to the variability of the North Atlantic Oscillation (NAO).
    • Mechanisms of Pacific Decadal Variability in ESMs: The Roles of Stochastic Forcing, Feedbacks & External Forcing,” led by Emanuele DiLorenzo at Georgia Tech Research Corporation, is developing a thorough assessment of mechanisms that drive Pacific decadal variability (PDV) across tropical and extra-tropical regions using simulations from the Coupled Model Intercomparison Project (CMIP) and E3SM to aid in predicting droughts, heatwaves, and ecosystem changes.
    • “Decadal Prediction and Predictability of Extremes in Ocean Eddy Resolving Coupled Models,” led by Benjamin Kirtman at the University of Miami (School of Marine and Atmospheric Science), is investigating how ocean mesoscale features relate to modes of decadal variability and is diagnosing how these modes correlate to regional extremes in the United States. The project will use two ocean-eddy-resolving models (E3SM and CESM2) and evaluate the decadal prediction capabilities of the models.
    • “Reducing Uncertainty of Polar to Midlatitude Linkages Using DOE’s E3SM in a Coordinated Model-Experiment Setting,” led by Gudrun Magnusdottir at the University of California, Irvine, is researching polar-tropical connections, tropospheric-stratospheric connections, and the complex mechanisms and feedbacks between the ocean, sea ice, and atmosphere through simulations from E3SM and a suite of models participating in the Polar Amplification Model Intercomparison Project (PAMIP), a CMIP6 project.


    These projects will advance DOE’s E3SM model and further its progress toward the design of earth system codes for leadership class computers and in support of energy science and mission requirements.

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