Can Chicago's skyline predict the weather? Argonne scientists investigate urban canyons

CHICAGO - When it comes to Chicago weather, we all know the saying – if you don’t like it, wait 15 minutes.

Now, scientists at Argonne National Laboratory are attempting to make Windy City weather a little more predictable by studying what's called "urban canyons" and they are in downtown Chicago.

In a Fox 32 special report, chief meteorologist Emily Wahl tracks this groundbreaking research.

Chicago is known for its iconic skyline and as the birthplace of the skyscraper. But little is known about how these architectural masterpieces affect the weather.

To find out, a group of Argonne scientists - along with university researchers, students and community groups - spent two weeks collecting never-before-seen weather data from urban canyons in downtown Chicago.

Wait, canyons in Chicago?

"Chicago is an urban canyon," said Scott Collis of Argonne National Lab. "It’s a massive - you actually look at the whole downtown area from Streeterville down to South Loop. But full of urban canyons."

Collis manages Argonne's Community Research on Climate and Urban Science (CROCUS) team.

"An urban canyon is an area in the city with tall buildings, where the buildings are much taller than the distance between them. These urban canyons, they're not represented in climate simulations or even weather simulations. So, we don’t know what influence they have on the weather around them," Collis said.

The group studied a shallow urban canyon that stretches east on Roosevelt Road from the University of Illinois-Chicago campus to the Shedd Aquarium and a deeper one in the financial district.

The overall goal is to see how the city skyline affects the weather and vice versa.

Fox 32 was with them when a group of researchers first set out on foot near the lakefront. Using portable weather stations, they measured the temperature, wind direction and other weather variables, both in the sun and the shade.

Before heading to the Shedd, students started taking their weather measurements at Michigan Avenue and Roosevelt Road.

"We picked that avenue because our computer simulations show that’s where we expect the biggest influence of the urban canyon," Collis said.

Collis said urban canyons can do a variety of things like reducing wind speed.

"What we don’t know is their impact on something called atmospheric turbulence. We don’t know how choppy it makes the atmosphere. You know when you’re kind of landing in at O’Hare. And you get below a certain altitude and all of a sudden the seatbelt sign comes on, and the plane is rocking around," Collis said.

After they finished their ground measurements, these researchers took their eyes to the skies.

The Gary Comer education campus on the South Side is one of three locations where the research team released heat balloons to gather more weather data, this time outside an urban canyon.

"We’re going to put enough helium in the balloon that it will only get up to just above the building heights. They’re going to then drift over the buildings there," Collis said.

The small digital devices in the biodegradable cups - attached to party balloons - captured the weather conditions and sent that information to the team back on the ground.

"This is the high spectral resolution radar (HSRL)," said Tim Wagner. "It shoots a big green laser beam into the sky, and it measures pollution."

Wagner, a weather researcher from the University of Wisconsin, assisted Argonne’s urban canyon research by working in a high-tech mobile meteorology lab using a laser to gather microscopic data.

"It’s actually capturing a layer of smoke that’s been over the city. This smoke is too thin for us to see with the naked eye, but we can see with our instruments," Wagner said.

As the group finished its two-week data collection project, Fox 32 caught up Collis one more time for a sneak peek at the initial results.

"One thing we’re also seeing is the role in which the green spaces in and around the urban canyon are having in cooling off the worst impacts of the heat," Collis said.

That’s an issue Naomi Davis is all too familiar with.

"Well there is the 1995 tragedy of 736 heat related deaths in the city of Chicago," Davis said. "And the understanding that already compromised health conditions are exacerbated by heat in ways that can and have proven fatal."

Davis is the founder and CEO of Blacks in Green. It’s one of several community groups partnering with Argonne in its urban canyon field research.

She hopes it will lead to more trees and green spaces on the South Side to help Black and brown communities withstand the effects of climate change.

"So we know that we have homes where residents don’t afford or don’t use air conditioning. We understand that there are issues of pollution in our neighborhoods that are disproportional," Davis said.

She said the area around 64th Street and Cottage Grove Avenue is a good example of what's called a "heat island" where the temperature outside gets hotter because there are few - if any - trees or green space.

Collis said trees are important because they literally sweat and make the air cooler through a process called "evaporative cooling."

Before Collis and his team can try to answer any questions about heat islands, urban canyons or Chicago weather, they have an avalanche of data to analyze.

"It’s all in the name of not only making weather more predictable but improving our understanding of a city like Chicago," Collis said.

"Our climate models assume Chicago is the same. There’s no difference between Humboldt Park, there’s no difference between West Woodlawn or downtown Chicago. CROCUS is collecting the data to represent Chicago," Collis added.

Over 40 researchers from various labs, universities and community groups helped collect the urban canyon data.

Argonne said other researchers will be able to use this information for years to come, and the initial results are expected to be presented at scientific meetings by the end of the year.