NASA Powers Up Climate Change Modeling Capability

Scientists got their first glimpse Aug. 24 of NASA’s expanded high-end computing system that will serve as the modeling centerpiece of a new climate simulation. The expansion added 4,128 computer processors to Goddard Space Flight Center’s Discover high-end computing system.
The IBM iDataPlex “scalable unit” uses Intel’s newest Xeon 5500 series processors, which are based on the “Nehalem” architecture introduced earlier in 2009.
“We are the first high-end computing site in the United States to install Nehalem processors dedicated to climate research,” Phil Webster, chief of CISTO (Computational and Information Sciences and Technology Office) at Goddard, said in a statement Aug. 25. “This new computing system represents a dramatic step forward in performance for climate simulations.”
In preliminary testing of Discover’s Nehalem processors, NASA climate simulations performed up to twice as fast per processor as other nationally recognized high-end computing systems. In addition, the new computational capabilities allow NASA climate scientists to run high-resolution simulations that reproduce atmospheric features not previously seen in their models, NASA said.
Moreover, stimulus funds from the American Recovery and Reinvestment Act will allow the installation of another 4,128 Nehalem processors later in 2009, bringing Discover to 15,160 processors.
“Nehalem architecture is especially well-suited to climate studies,” said Dan Duffy, CISTO lead architect. “Speed is an inherent advantage for solving complex problems, but climate models need large memory and fast access. We configured our Nehalem system to have 3GB of memory per processor, among the highest available today, and memory access is three to four times faster than Discover’s previous-generation processors.”
Goddard’s GMAO (Global Modeling and Assimilation Office) typically runs its flagship Earth Observing System Model at 27-kilometer resolution. With the new Nehalem processors, the GMAO has been testing a special “cubed-sphere” version at resolutions as high as 3.5 kilometers.
“Once the model goes below 10-kilometer resolution, features such as well-defined hurricane eyewalls and convective cloud clusters appear for the first time,” said William Putman, acting lead of the Advanced Software Technology Group in Goddard’s Software Integration and Visualization Office. “At these cloud-permitting resolutions, the differences are stunning.”
NASA climate simulation efforts also contribute to the U.S. Global Change Research Program, the U.S. Integrated Earth Observation System and the U.S. Weather Research Program. Supported international programs include UNESCO’s Intergovernmental Oceanographic Commission, the United Nations Environment Programme, the World Climate Research Programme, the World Meteorological Organization and the World Weather Research Programme.