News•September 28, 2012

Putting the Eyes of the Crowd on the Eye of Hurricanes

Ordinarily, it takes an advanced degree and years of training to become a bona fide hurricane expert. But thanks to an innovative new project, ordinary citizens can make a real contribution to hurricane science armed with little more than an internet connection, a sharp eye and a bit of enthusiasm.

The project is known as Cyclone Center, and it’s designed to crowdsource one of the most important questions facing scientists: how strong are the winds in the average hurricane or typhoon?

Hurricane Ike as seen from the Internation Space Station. Credit: flickr/NASA

It matters because climate scientists believe that these devastating storms are likely to become fewer in number, but more intense over the coming century thanks to global warming. But if you don’t know what the average hurricane intensity is today, there’s no way to gauge whether intensity is on the rise.

Unfortunately, most hurricanes never have their wind speeds measured directly. Instead, scientists look at satellite images and apply something known as the “Dvorak technique,” which uses details in the shapes of hurricanes’ cloud formations to estimate how fast their winds are blowing.

The problem, said Chris Hennon, an atmospheric scientist at the University of North Carolina, Asheville and a principal investigator on the Cyclone Center project, is that “different agencies that use the Dvorak technique can come up with estimates of wind speed for a single storm that vary by 50-60 knots. It’s somewhat subjective.”

Cyclone Center’s answer is to use the wisdom of crowds to narrow down the estimates. “The main advantage of a citizen-science approach is that dozens of people, rather than one or two, will analyze a single image,” said Thomas Karl, director of NOAA’s National Climatic Data Center, in a press release.

“If you have 50 people looking at a photograph,” Hennon said, “and 40 of them agree on a hurricane’s intensity, you’ve got a real consensus.”

It might be a more rock-solid consensus if the 50 were climate scientists, but with some 300,000 images to go through, representing about 100 photos of every hurricane over the past three decades, there’s no way the climate-science community could even come close. To gauge the crowdsourcing accuracy, Cyclone Center includes images of some storms whose wind speeds have been measured.

Even with pros like Hennon and Karl endorsing it, Cyclone Center might sound a little dubious, but a similar strategy has worked amazingly well for other branches of science. The concept was born back in 2007 when, a group of astronomers decided to recruit citizen-scientists for a project to classify thousands upon thousands of galaxies by their shapes — a project that would have taken forever if left to the scientists alone.

Credit: flickr/coreburn

That project, called Galaxy Zoo, was wildly successful, so the founders branched out to other, similar efforts. Collectively known as Zooniverse and headquartered at Chicago’s Adler Planetarium, the projects have let ordinary citizens discover planets orbiting distant stars, detect patterns in whale songs and more.

Now it’s the cyclones’ turn. Anyone with a computer can go to the site, sign up, and make a contribution to climate science. Eventually, visitors to the Adler will be able to do the same from kiosks right in the building.

The scientists in charge don’t expect to see big changes in hurricane intensity due to climate change over the 30-year period from about 1980 to today. The time is too short, and hurricanes are influenced by all sorts of natural cycles, not just by human-caused global warming.

What they do expect, however, is that the data provided by the citizen-scientists who visit Cyclone Center will provide a baseline against which future changes in hurricane intensity can be measured. If scientists can ever say with confidence that climate change really is making hurricanes more powerful, they may have a bunch of ordinary folks to thank.