Robert D. Ferraro

Satellite Observations for CMIP5: The Genesis of Obs4MIPs

The objective of the Observations for Model Intercomparison Projects (Obs4MIPs) is to provide observational data to the climate science community, which is analogous (in terms of variables, temporal and spatial frequency, and periods) to output from the 5th phase of the World Climate Research Programmes (WCRP) Coupled Model Intercomparison Project (CMIP5) climate model simulations. The essential aspect of the Obs4MIPs methodology is that it strictly follows the CMIP5 protocol document when selecting the observational datasets. Obs4MIPs also provides documentation that describes aspects of the observational data (e.g., data origin, instrument overview, uncertainty estimates) that are of particular relevance to scientists involved in climate model evaluation and analysis. In this paper, we focus on the activities related to the initial set of satellite observations, which are being carried out in close coordination with CMIP5 and directly engage NASAs observational (e.g., mission and instrument) science t...

The Earth System Prediction Suite: Toward a Coordinated U.S. Modeling Capability

The Earth System Prediction Suite (ESPS) is a collection of flagship U.S. weather and climate models and model components that are being instrumented to conform to interoperability conventions, documented to follow metadata standards, and made available either under open source terms or to credentialed users. The ESPS represents a culmination of efforts to create a common Earth system model architecture, and the advent of increasingly coordinated model development activities in the U.S. ESPS component interfaces are based on the Earth System Modeling Framework (ESMF), community-developed software for building and coupling models, and the National Unified Operational Prediction Capability (NUOPC) Layer, a set of ESMF-based component templates and interoperability conventions. This shared infrastructure simplifies the process of model coupling by guaranteeing that components conform to a set of technical and semantic behaviors. The ESPS encourages distributed, multi-agency development of coupled modeling systems, controlled experimentation and testing, and exploration of novel model configurations, such as those motivated by research involving managed and interactive ensembles. ESPS codes include the Navy Global Environmental Model (NavGEM), HYbrid Coordinate Ocean Model (HYCOM), and Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS®); the NOAA Environmental Modeling System (NEMS) and the Modular Ocean Model (MOM); the Community Earth System Model (CESM); and the NASA ModelE climate model and GEOS-5 atmospheric general circulation model.

Parallel Computation Applied to Electromagnetic Scattering and Radiation Analysis

Abstract We have been applying the computational power of parallel processing to the solution of large-scale electromagnetic scattering and radiation problems. Several analysis codes have been implemented on the Jet Propulsion Laboratory/California Institute of Technology Mark IIIfp Hypercubes. The first code to be implemented was the Numerical Electromagnetics Code (NEC-2) from Lawrence Livermore National Laboratory. At first we simply ported it to run in the parallel processing environment. Since that time, taking advantage of the large hypercube memory and fast computation. we have enhanced parallel NEC to permit iterative design and analysis. Three other codes, frequency domain finite elements, time domain finite difference, and frequency selective surfaces, have been largely or completely developed within this parallel processing environment. Because of the massive problem size of the typical electromagnetics problem, our work is an important influence in determining the development of hardware, syst...

A Global Repository for Planet-Sized Experiments and Observations

AbstractWorking across U.S. federal agencies, international agencies, and multiple worldwide data centers, and spanning seven international network organizations, the Earth System Grid Federation (ESGF) allows users to access, analyze, and visualize data using a globally federated collection of networks, computers, and software. Its architecture employs a system of geographically distributed peer nodes that are independently administered yet united by common federation protocols and application programming interfaces (APIs). The full ESGF infrastructure has now been adopted by multiple Earth science projects and allows access to petabytes of geophysical data, including the Coupled Model Intercomparison Project (CMIP)—output used by the Intergovernmental Panel on Climate Change assessment reports. Data served by ESGF not only include model output (i.e., CMIP simulation runs) but also include observational data from satellites and instruments, reanalyses, and generated images. Metadata summarize basic infor...

Evolving Obs4MIPs to Support Phase 6 of the Coupled Model Intercomparison Project (CMIP6)

AFFILIATIONS: FeRRaRo anD WaliseR—Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California; GleckleR anD tayloR—Lawrence Livermore National Laboratory, Livermore, California; eyRinG—Deutsches Zentrum fur Luftund Raumfahrt, Institut fur Physik der Atmosphare, Oberpfaffenhofen, Germany CORRESPONDING AUTHOR: Robert Ferraro, Jet Propulsion Laboratory, MS 301-330, 4800 Oak Grove Dr., Pasadena, CA 91109-8099 E-mail: robert.d.ferraro@jpl.nasa.gov

Parallel Computing at the NASA Data Assimilation Office (DAO)

The goal of atmospheric data assimilation is to produce accurate gridded datasets of fields by assimilating a range of observations along with physically consistent model forecasts. The NASA Data Assimilation Office (DAO) is currently upgrading its end-to-end data assimilation system (GEOS DAS) to support NASAs Mission To Planet Earth (MTPE) Enterprise. This effort is also part of a NASA HPCC Earth and Space Sciences (ESS) Grand Challenge PI project. Future Core computing, using a modular Fortran 90 design and distributed memory (MPI) software, will be carried out at Ames Research Center. The algorithmic and performance issues involved in the Core system are the main subjects of this presentation.

Comparing 3D finite element formulations modeling scattering from a conducting sphere

Six tetrahedral finite-element varieties are used to model the frequency-domain open-region scattering problem of a ka=2 conducting sphere. A wave-absorbing boundary condition is imposed at kr=3. Linear and quadratic node-based elements display vector parasites, which are less significant in the quadratic element case. Whitney edge elements improve with increasing mesh density, but accuracy is costly due to approximately linear h-convergence. Whitney elements also result in acceptably fast convergence of a biconjugate gradient iterative solver, alone among the elements examined. Novel weighted Whitney elements show some effectiveness and appear free of vector parasites, but are not as cost-effective as Whitney elements. Higher-order tangential elements appear cost-effective, in that accurate solutions may be obtained at low mesh density. >

A general purpose sparse matrix parallel solvers package

A package of three parallel solvers with a unified user interface is developed for sparse symmetric complex linear systems arising from the discretization of partial differential equations on unstructured meshes. Once the data interface is set up, the package constructs the sparse symmetric complex matrix, and solves the linear system using one of the following methods: a bi-conjugate gradient solver, a two-stage Cholesky LDL/sup T/ factorization, or a hybrid solver combining the above two methods. The user deals only with local matrices on local mesh partitions in each processor. Scaling problem size N with the number of processors P with N/P fixed, test runs on Intel Delta up to 28 processors show that the bi-conjugate gradient method scales linearly with N whereas the hybrid method scales as /spl radic/N.<<ETX>>

An element-based concurrent partitioner for unstructured finite element meshes

A concurrent partitioner for partitioning unstructured finite element meshes on distributed memory architectures is developed. The partitioner uses an element-based partitioning strategy. Its main advantage over the more conventional node-based partitioning strategy is its modular programming approach to the development of parallel applications. The partitioner first partitions element centroids using a recursive inertial bisection algorithm. Elements and nodes then migrate according to the partitioned centroids, using a data request communication template for unpredictable incoming messages. Our scalable implementation is contrasted to a non-scalable implementation which is a straightforward parallelization of a sequential partitioner. The algorithms adopted in the partitioner scale logarithmically, as confirmed by actual timing measurements on the Intel Delta on up to 512 processors for scaled size problems.

Physics Modeling of Tokamak Transport, a Grand Challenge for Controlled Fusion

A challenge facing fusion is accurate prediction and understanding of plasma and heat confinement. Com puters and modeling techniques have advanced to where we can envision simulating real Tokamaks start ing from fundamental physics models. Charged parti cles in magnetic fields execute rapidly gyrating mo tions about the field. These orbits gradually drift where electric fields and magnetic nonuniformities exist. The gyrokinetic model averages out the rapid gyration and treats the plasma as a large number of drifting rings of charge and current; large numbers (approx. 106) of such rings are followed in their self-consistent electric and magnetic fields. Three-dimensional simulations of plasma and heat confinement for situations relevant to fusion give turbulence spectra and transport coeffi cients similar to experiments. Simpler particle models of plasma run on hypercubes achieves a high degree of parallelism (95%). With new parallel machines sub stantial gains in speed and memory can be expected; modeling of real Tokamaks should be possible.