Supercomputer’s mission: super-accurate weather forecasts

Published 5:00 am Tuesday, June 12, 2012

CHEYENNE, Wyo. — Here in the shortgrass prairie, where being stuck in the ways of the Old West is a point of civic pride, scientists are building a machine that will, in effect, look into the future.

This month, in a barren Wyoming landscape dotted with gopher holes and hay bales, the federal government is assembling a supercomputer 10 years in the making, one of the fastest computers ever built and the largest ever devoted to the study of atmospheric science.

The National Center for Atmospheric Research’s supercomputer has been dubbed Yellowstone, after the nearby national park, but it could have been named Nerdvana. The machine will have 100 racks of servers and 72,000 core processors, so many parts that they must be delivered in the back of a 747. Yellowstone will be capable of performing 1.5 quadrillion calculations — a quadrillion is a 1 followed by 15 zeros — every second.

That’s nearly a quarter of a million calculations, each second, for every person on Earth.

In a little more than an hour, Yellowstone can do as many calculations as there are grains of sand on every beach in the world.

The study of climate and weather patterns has always been hamstrung by volatility — by elements of chaos in the seas and the air. That challenge is most famously summed up by the “butterfly effect,” the idea that the flapping of a butterfly’s wings on the coast of Africa can determine whether a hurricane will strike New Orleans.

The sheer speed of Yellowstone is designed to burst through the limits of chaos theory — the difference, allegorically, between predicting the odds of blackjack after playing five hands versus playing a million. The machine is expected to give scientists a clearer image of the state of the planet, and its future, revolutionizing the study of climate change, extreme weather events, wildfires, air pollution and more.

“These are chaotic systems, but it’s just math,” said Richard Loft, director of technology development at NCAR’s Computational and Information Systems Laboratory. “We play statistics in the climate game. We feed in the basic laws of science, and out comes something that looks like the Earth’s climate. It’s an instrument. This is a mathematical telescope.”

NCAR is in the business of research, not forecasting, but the tools and advances produced from its research could have a profound effect on forecasting. Armed with a high-fidelity portrait of Earth systems, scientists around the United States can begin to pinpoint the regional impact of changes in the weather and atmosphere.

Rather than warning of a tornado risk in the central U.S. between noon and 9 p.m., scientists might one day warn of a tornado risk in Woodson County, Kan., between 1 and 3 p.m. Rather than warning of a hurricane striking the coast of Texas, they hope to be able to warn of a hurricane striking the town of Freeport, with a top wind speed of 90 mph and a tidal surge of 41⁄2 feet.

That regional accuracy is particularly critical in the study of climate change. “The disaster of climate change happens on a regional scale,” Loft said. “Everything is connected.”

For example, once scientists use Yellowstone to help predict the melting of ice at the North Pole, which means significant change in nearby waters, they can better predict the patterns of storms that form in the Gulf of Alaska. Then Yellowstone can help predict how those storms will deposit snow atop the Sierra Nevada, down to precise changes in elevation on individual faces of mountains.

That snow will melt, and the water will run downhill — which means Yellowstone can help predict how much water California will have to drink, even the most efficient locations to build the state’s reservoirs.

“It’s taking the macro information and applying it to the things that matter,” said Richard Neale, an NCAR project scientist.

The computer will be housed in a futuristic, $70 million compound west of Cheyenne. The National Science Foundation, which funds NCAR, is paying $50 million of the tab. The state of Wyoming will pay for the rest. In exchange, the state will occupy a dedicated chunk of the computer’s power and memory. University of Wyoming scientists hope to use Yellowstone to advance “carbon sequestration,” a promising method of storing harmful gases underground to combat climate change and open new avenues in industry.

Yellowstone will replace NCAR’s Bluefire system, a supercomputer in its own right, though this one will have roughly 30 times the throughput of the old system.

Yellowstone will hold 600 sets of atmospheric data in its vast memory bank — temperatures, humidity, wind motion, rainfall. Information gleaned from the world’s data-collection systems — buoys in the ocean, wind monitors fastened to the top of telephone poles — will be added to the archive.

The bulk of the machine will arrive at the 24-acre compound this month. Once the racks are lashed together, scientists will spend weeks “basically trying to break the system,” said Anke Kamrath, director of operations and services at NCAR’s systems lab. If they can’t, they’ll open it to researchers from across the nation, probably in August.

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