Forecasting the danger

Press the play button to see how Carolina researchers have developed a leading tool for forecasting storm surge and coastal flooding during hurricanes.

When Rick Luettich first arrived at UNC-Chapel Hill 25 years ago, he was struck by how irregular and complex water behavior was along the coastline.

Models that predicted movements of ocean waters were suited only for areas in the middle of the ocean and not where they were most needed — where people live.

That’s why researchers at Carolina have spent two decades developing a software package called ADCIRC, which predicts how the ocean waters will move and how high they will get. ADCIRC is now a leading tool for forecasting storm surge and coastal flooding during hurricanes.

“It makes an area safer to live in,” said Luettich, director of the UNC Institute of Marine Sciences. “It allows people to make decisions in advance of storms, about how they should react to events as they come. So really we’ve been able to translate our research and knowledge into things that have a huge impact on society.”

Today, ADCIRC is used by academics for research, engineers to design levee systems and the National Weather Service and NC Emergency Management to forecast flooding and determine the best course of action for residents on the coast.

To provide users with the potentially life-saving information, the program utilizes a combination of creative applications of basic physics principles and a lot of computing power. ADCIRC has grown from running on mainframes to running on state-of-the-art supercomputers to produce that information quickly.

“What supercomputers allow us to do is to tackle these problems at a scale we never imagined,” Luettich said. “We can go from an ocean scale of hundreds of kilometers down to a street scale of tens of meters and resolve everything in between.”

The development of ADCIRC has been the result of collaboration across disciplines and organizations with input from the Institute of Marine Sciences, Department of Marine Sciences, the Renaissance Computing Institute and the DHS Coastal Resilience Center of Excellence.

Brian Blanton, an oceanographer and senior research scientist at RENCI, worked closely with Luettich to push ADCIRC forward in the computer science world.

“ADCIRC is a piece of software — it’s a Fortran code,” Blanton said. “However, there’s a lot of computer science in that Fortran code. There’s a lot of oceanography and earth sciences that are in that code. So, even at that level different communities and threads of thought have to come together to be cast in a piece of software.

“UNC is one of those places where a lot of these expertises come together.”