High-Order Method Modeling Environment

The High-Order Method Modeling Environment (HOMME) is a vehicle to investigate using high-order-element-based methods to build conservative and accurate dynamical cores.

Numerical Methods: HOMME

The future evolution of the Community Climate System Model (CCSM) into an Earth System model will require a highly scalable and accurate flux-form formulation of atmospheric dynamics: flux form is required to conserve long-lived trace species in the stratosphere; accurate numerical schemes are essential to ensure high-fidelity simulations capable of capturing the convective dynamics in the atmosphere and their contribution to the global hydrological cycle; scalable performance is necessary to exploit the massively parallel petascale systems that will dominate high-performance computing (HPC) for the foreseeable future. This activity directly supports NCAR's mission "to understand the behavior of the atmospheric and related systems and the global environment."

The High-Order Method Modeling Environment (HOMME), developed by the Computational and Information Systems Laboratory at the National Center for Atmospheric Research (NCAR), is a vehicle to investigate using high-order-element-based methods to build conservative and accurate dynamical cores. Currently, HOMME employs the discontinuous Galerkin (DG) and spectral element methods on a cubed-sphere tiled with quadrilateral elements, can be configured to solve the shallow water or the dry/moist primitive equations, and has been shown to efficiently scale to 32,768 processors of an IBM BlueGene/L (BG/L).

The objective of this project is to extend HOMME to a framework capable of providing the atmospheric science community a new generation of atmospheric general circulation models (AGCMs) for CCSM based on high-order numerical methods on the cubed-sphere that efficiently scale to hundreds-of-thousands of processors, achieve scientifically useful integration rates, provide monotonic and mass conserving transport of multiple species, and easily couple to community physics packages such as Community Atmosphere Model (CAM) physics. Achieving these objectives will allow climate scientists to take full advantage of the extraordinary petascale computing capabilities being deployed by NSF in the next five years and will lead to dramatic increases in climate science productivity. The development timeline is such that the proposed technology will be (freely) available to the community for the Intergovernmental Panel on Climate Change (IPCC) fifth assessment science runs, currently scheduled to begin in April 2010. To achieve this requires work in four areas: physics, validation and verification, time integration, and scalability.

This effort supports NCAR's strategic priorities of "Developing and providing advanced services and tools" and "Creating an Earth system knowledge environment." In addition to NSF core support, the Department of Energy's Climate Change Prediction Program (CCPP) and the Scientific Discovery through Advanced Computing (SciDAC) programs sponsor this research.