Titan, a supercomputer as powerful as 300,000 laptops

Titan, a supercomputer at Oak Ridge National Laboratory, can do quadrillions of math problems per second. Photo provided by Oak Ridge National Laboratory, U.S. Dept. of Energy.

A computer that crunched data for climate studies sits in a football field-sized warehouse in Oak Ridge, Tenn., and has the computing power of 300,000 laptops. It's so robust that it can do more than 10 quadrillion simple math problems per second. It's called Titan.

Even so, climate simulations are so complex that scientists run programs on these supercomputers for months at a time.

These models break the earth into rectangles and other shapes and then analyze how they respond to changes in the atmosphere and ocean. These rectangles are like pixels on a TV screen, said Forrest M. Hoffman of the Climate Change Science Institute at Oak Ridge. 

In the past, those rectangles represented large geographic areas, often hundreds of square miles — large pixels. This frustrated efforts to get clear pictures of what was happening in smaller geographic areas, including the complex currents and eddys of the Gulf Stream.

But Hoffman and other scientists have been working on ways to increase the resolution of these models. 

Vincent Saba, a National Oceanic and Atmospheric Administration biologist working at a lab at Princeton University, said old models were like watching a football game on an old television: “You could barely make out the football.” Now, the colors and shapes are clear and breathtaking. Same with climate models. 

Saba said his research team recently took data on sea surface temperatures and other factors over time and plugged it into a climate model. The program ran for days at a time. The complexity was mind-numbing.

"You’re trying to model the earth’s climate so you have all these layers, ice models, changes in the ocean, atmosphere."

One limiting factor is the cost of running these programs on super computers such as Titan. Demand is high.

"It's like reserving time on the Hubble Space Telescope," Hoffman said.

It's also expensive. Powering Titan and its storage facilities requires as much as 20 Megawatts, enough power to run 2,000 homes.

But just as hurricane models help predict paths of tropical storms, these large climate programs will be an increasingly important tool in understanding ocean currents.

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For a deeper dive into the Gulf Stream and the amazing and disturbing things happening to it, visit our new special report: Into the Gulf Stream

Reach Tony Bartelme at 843-937-5554. Follow him on Twitter @tbartelme.

Tony Bartelme is senior projects reporter for The Post and Courier. He has earned national honors from the Nieman, Scripps, Loeb and National Press foundations and is a three-time finalist for the Pulitzer Prize. Reach him at 843-937-5554 and @tbartelme