But the gap does not just pose the threat of a brain drain, Dr. Fein and other experts say. They say there are potential economic and security problems if there are delays answering climate questions that are a priority for the United States like whether global warming will eliminate the winter mountain snows that supply California with three-quarters of its water in summer. The heart of the effort, which had been requested by Congress, was a series of modeling studies that had to be run on computers in Britain, Canada and Japan because American climate centers lacked the capacity to perform the calculations. Those computers might not always be available to serve American needs, the experts say. And the gap may soon widen.
Japan is poised to leapfrog past everyone in the quest for model power.
A typical computer array used for climate modeling in the United States can process about 20 gigaflops, or 20 billion floating-point operations per second, recent studies say. European centers are routinely running beyond 100 gigaflops. The Japanese machine's performance will be measured in teraflops, or thousands of gigaflops. But better computers and organization are only part of the picture, the experts say. Better monitoring of conditions that influence the current climate is crucial, Dr. Sarachik's April study concluded.