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Next-Generation Computer Model for Space-Weather Specification and Forecasting, 15-9026

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Principal Investigators
Geoffrey Crowley
Christopher J. Freitas

Inclusive Dates: 04/01/97 - Current

Background - The term space-weather refers to those conditions on the sun, in the solar wind, magnetosphere, ionosphere, thermosphere, and mesosphere, that can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health. Adverse conditions in the space environment can cause disruption of communications, navigation, electric power distribution grids, and satellite operations, leading to a broad range of socio-economic losses. The National Space Weather Program (NSWP) is a new initiative designed to address many of the unresolved aspects of space weather (including theory, modeling, and measurements) in a unified manner. The U.S. Air Force, Navy, National Science Foundation, and NASA jointly fund the NSWP initiative. One goal of the NSWP is to produce weather forecasts for the various regions of space ranging from the sun to the earth's middle atmosphere.

 Approach - The goal of this project is to develop a space weather model spanning the mesosphere, ionosphere, and thermosphere. The new model will be based on an existing computer code that runs on CRAY Supercomputers at the National Center for Atmospheric Research. This code, called the Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIME-GCM), is widely acknowledged to be the premier space weather code. This code will be modified by SwRI to run in a distributed parallel-computing environment and to use a variable grid size. The Research Initiative Program in Advanced Modeling and Simulation (RIP-AMS) was an interdivisional collaboration that resulted in the enhancement and expansion of SwRI capabilities in high-performance parallel computing. The RIP-AMS program resulted in parallel-computing techniques that permit significant improvements in the runtime of computer codes. Specifically, algorithms based on domain decomposition strategies have been developed, providing a framework that will be applied to the TIME-GCM code, allowing a natural method for parallelization and incorporation of variable grid size regions.

Accomplishments - The existing serial code that runs on CRAY computers was ported to workstations at SwRI. The specialized CRAY commands currently in the code were replaced by system-independent commands. The code was modified to use the SwRI Distributed Computing Facility by inserting PVM commands in appropriate locations. The research team has tested the parallelized code and demonstrated significant speedup factors using up to ten nodes.

Intelligent Systems, Advanced Computer and
Electronic Technology, and Automation Program
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