In the wake of Hurricane Katrina, scientists and research centers from across the country have come together to try to provide crucial information on the contaminated floodwaters to haz-mat and public health officials. The National Center for Supercomputing Applications is playing a starring role in this effort by providing rapid-response computing capability.

Floodwaters containing organic and chemical pollutants, such as sewage and oil, cover swaths of Mississippi and Louisiana. There is potential for additional spills as commerce resumes in the Gulf. In order to prepare to respond to spills and aid cleanup, the National Oceanic and Atmospheric Administration's Office of Response and Restoration is ensuring that key surface current information will be available for input to its trajectory model. To support the response, scientists at NOAA's Office of Coast Survey are attempting to develop near-shore high-resolution forecasts that may be valuable as input to hazards trajectory models.  Both offices reside in NOAA's National Ocean Service.

A group of researchers, including Richard Luettich and Brian Blanton, two marine scientists at the University of North Carolina-Chapel Hill, has developed a three-dimensional hydrodynamic code, called ADCIRC, that can be used to model water levels and circulations. Previously, ADCIRC has been used only for after-the-fact analysis of coastal flows. In this case, however, NOAA officials believed it could be used to predict answers during a crisis.

Blanton and Luettich knew that in order to simulate the required 60 days of water velocity and water surface elevation, they would need more computational power.

"If we had a month to do these runs, we could do it on our desktop or on a small cluster, but to do it literally overnight it does require some horsepower," Blanton said.

Researchers found the horsepower they needed at NCSA, the National Science Foundation-supported supercomputing center located at the University of Illinois at Urbana-Champaign.

NCSA staff quickly provided access to the necessary computational power. Using 256 nodes of NCSA's 16-teraflop Dell Xeon system, called Tungsten, the researchers were able to complete the required computational runs in about 15 hours, from midnight on Sunday, Sept. 11 to mid-day on Monday, Sept. 12.

"During times of crisis, information is key," said NCSA Director Thom Dunning. "By providing rapid-response computing capability, NCSA can give decision makers the right information at the right time."

Now NOAA scientists are working to integrate the baseline information provided by these computational runs with NOAA's North American Mesoscale Model, a code to simulate wind speed, direction and other meteorological factors. The goal is to provide daily forecasts of coastal circulation that can be used to drive trajectory models for tracking pollutants in the Katrina-affected region, information that will be vital as cleanup efforts and recovery continue.

"We are trying to be prepared and to meet the needs for reliable information that the hazardous materials experts will need to have," said OCS scientist Jesse Feyen. "We're doing that and we're doing it quickly."