Tropical Storm Isaac, currently blowing northwest through the Caribbean Sea, is forecast to pass Florida’s western coast on Monday and Tuesday – just as delegates, public officials, media and observers open the 2012 Republican National Convention in Tampa.
Thousands of people are traveling to the region this weekend. They might be asking themselves, how do facility builders and owners know if the convention center and hotels can hold?
One answer: Researchers build powerful machines capable of generating hurricane-force winds in a controlled area, to see what blows to pieces and what holds together. The results help businesses and insurers better evaluate the risks to building materials, vehicles and people in powerful storms.
On Tuesday, Florida International University in Miami unveiled the latest update to its Wall of Wind, a hurricane simulator. The array can now generate top speeds of 157 mph, the minimum for a Category 5 hurricane, the highest level on Saffir-Simpson scale. It's the fastest hurricane-wind research lab on Earth, said Arindam Chowdhury, director of wind engineering research. By Tuesday, Isaac is forecast to be a Category 1 hurricane, with wind speeds anywhere between 74 and 95 mph.
``With this high probability of hurricanes of hitting the East Coast and in the Gulf of Mexico, I think this is the most wise investment any university can do,” Chowdury said in a phone interview yesterday.
The 12-fan, 15-by-20-foot testing area has been upgraded since FIU's International Hurricane Research Center built a two-fan prototype, which could generate speeds of up to 120 mph, in 2007. The IHRC has spent about $13 million overall, Chowdhury said, with funding coming from the U.S. Department of Energy, the state of Florida and the state’s Center of Excellence for Hurricane Damage Mitigation and Product Development, which kicked in $7.5 million.
Chowdhury and his team of about 20 -- research scientists, lab managers, faculty and students -- first tested the new Wall of Wind in March and have been huffing and puffing and blowing down everything from rooftop air conditioning units and solar panels to street signs and traffic lights. In one test, shingles rated strong enough to withstand 130-mph winds were ripped away at 109 mph.
More than half of the U.S. population lives near water, Chowdhury said, and many of those costal residents know that spring, summer, fall and winter have a fifth sibling – hurricane season. ``You have to build hurricane-resistant communities,'' he said.
Climate change is projected to increase the global frequency of intense hurricanes – Category 3 or higher, according to Kerry Emanuel, professor of atmospheric science at the Massachusetts Institute of Technology. The frequency of less-destructive, weak hurricanes is expected to go down. As with most climate-related projections, regional projections are less reliable than global ones.
Peak wind speed is important, and so is the duration and direction of gusts, Emanuel said. “If you double the wind, you're not going to get double the damage, you're going to get at least eight times the damage,” he said. “So that's why the wind-tunnel stuff is valuable.”
When they’re not generating winds that could flip a fire truck, the Wall of Wind research team also tests the effects of less extreme speeds on building materials, studying heat transfer, and water and air loss. ``We're not only looking at the extreme hurricane wind conditions but also environmental conditions that affect our day-to-day energy efficiency,'' Chowdhury said. These findings ``will make building materials that are sustainable, not only from the strength perspective but also from the energy-efficiency perspective.''
And how much larger can the Wall of Wind grow? Sixteen fans? Twenty? ``The probability of something higher than 160 mph is so low that the return on that investment, it would be diminishing returns if you tried anything higher,'' he said. ``There could be Cat-5 hurricanes with wind speeds of 175 mph, but there's a .001 percent chance of that hitting.'' Hurricane Andrew, which ravaged southern Florida in 1992, generated winds at that speed. Its estimated $27 billion in damages makes the Wall of Wind investment seem like flotsam.
Emanuel, a Republican, was subject to attacks -- a “frenzy of hate” -- early this year after commenting that Republicans pride themselves on the theme of responsibility but aren’t taking responsibility for collective harm to the climate system.
``For the hurricane problem, there are a lot of policy changes we could make that have nothing to do with climate change that would make us a lot more resilient,” Emanuel said. For a start, he said insurance premiums and building codes accurately reflect storm risk. “I don’t think it’s that difficult, I just think we’re in a culture where everyone thinks it’s difficult,” he said.
See how Floridians fare in the Top 20 Cities at Risk from Climate Change slideshow.
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