It was maybe the most colossal University science experiment ever.

Angela Cesere
LSA Freshman Hilary Bronson chases her ballon in the Big House on Saturday. (DAVID TUMAN/Daily)
Angela Cesere
Graphic by Gervis Menzies
Angela Cesere
A speculative view on the flow of wind
currents over Michigan Stadium
Graphic by Lindsey Ungar

But after an hour of trying to map the wind currents in Michigan Stadium, one of the largest football arenas in the nation, Prof. Perry Samson gazed into the stands and sighed.

“I’m clueless,” Samson said with a smile. “I’ll be surprised if we can get anything out of these tests.”

Experiments don’t always work. That’s what ran across the Atmospheric, Oceanic, and Space Sciences professor’s mind the night before Saturday’s experiment, when more than a hundred University students from AOSS classes would gather in the Big House to take wind measurements.

Samson, head organizer of the event, said earlier this year he began toying with an idea of having his students conduct wind measurements in the Big House.

Only lecturing your students on atmospheric forces isn’t enough, Samson said.

“Seeing is also half the battle.”

Curiosity and die-hard loyalty to the team also pushed Samson to ask the University for access to the stadium.

Perhaps an analysis of the wind currents might help a Michigan football kicker sharpen his aim in turbulent weather. Or the measurements might assist the University in better protecting the stadium from fires or an airborne pollutant. It was just a series of enticing questions worthy enough to explore.

After several months of asking a hesitant Athletic Department for stadium access, University officials gave Samson the go-ahead.

Samson then expanded the experiment to include students, graduate student instructors and faculty from six classes in the College of Engineering.

 

Forecasting the Stadium

To map out the wind currents of the stadium, the classes equipped themselves with the latest in weather technology along with balloons and bubble soap that could mark the movement of the wind for the students to see.

Dave Pawlowski, a Rackham student and event organizer, said faculty members decided to separate students into four experiments. Each group would measure specific features of the wind currents – like wind direction and temperature – with the students’ participation.

AOSS research scientist Frank Marsik, a faculty member who participated in the experiments, said because of the bowl-like shape of the arena some professors initially speculated wind passing over would spiral inside the stadium.

Engineering senior Elizabeth Siegel, a student in Samson’s AOSS 463 class also known as Air Pollution Meteorology, said students also predicated that incoming wind would cascade down the stands to the floor of the arena where the temperature is warmer and therefore at a lower pressure.

The wind would then naturally rise with the warming of the air on the football floor.

But several days before the experiment, Samson along with some of his students and faculty scoped out the arena. There they found pieces of trash floating across the stadium floor. Coincidently, the pieces of trash acted as visual markers that showed the direction of the wind.

“The trash was just crashing together,” Engineering senior Alex Braden said, adding that the wind was acting in an erratic pattern no one could really discern.

“You could watch it blow together. There was a lot of turbulence,” Samson said.

It was only a taste of the wind currents’ unpredictability that Samson and the students would see on Saturday. The night before the experiment, Samson couldn’t sleep.

 

Experimental difficulties

By noon on Saturday, students from six classes filed through the vacant stadium, clad in yellow t-shirts with the words Extreme Weather written on them.

At the center of the football field, AOSS faculty members set up a meteorological tower and weather balloon to record the vertical and horizontal wind conditions.

Scattered across the stadium seats floated blue balloons tied to the ground, each acting as a marker to indicate wind direction. Meanwhile Samson directed the students to his attention on the south end of the football field in what would mark the start of the experiment – bubble blowing.

Holding bubble bottles, dozens of students blew bubbles through the air to indicate the overall wind direction. But the hundreds of bubbles hovered up in the air in a chaotic motion.

About 15 minutes later, students lined in a “human dispersion” experiment where they released a neutrally buoyant balloon – a balloon filled with enough helium to prevent it from rising or dipping in the air – on the stadium floor.

One by one, students followed their balloon for about ten seconds before retrieving it and leaving a marker on where the balloon was recovered. In the end, the markers would indicate the dispersion of incoming wind plumes. Yet by the end of the experiment, the spatter of markers didn’t leave a distinct trail.

In the last moments, students holding balloons on twenty-foot-long strings stood across the football field in assigned positions to mark the different wind paths. But again, no evident pattern formed.

While the students thoroughly conducted the experiments, Samson said none led to any substantial results.

“The streamers (on the goal post) performed better than the balloons did,” Samson said. “The human dispersion experiment. Nothing expected happened with it.”

Although the faculty and students will need time to decipher the results, which were recorded on videotape, Samson said, “It’s very turbulent in here. The wind isn’t all that strong, but the mixing is greater than we thought.”

 

Back to the drawing board

Samson said the stadium is very symmetrical but there are clearly nuances within the stadium, which are causing the erratic flow of wind.

Research scientist Marsik said one of the factors that may have caused the erratic wind patterns could be due to the different colors throughout the sections of the stadium.

Because the dark colors absorb sunlight, Marsik said the different coloring of the sections might create various temperature levels throughout the stadium. The resulting temperature levels would create disparate pressure levels, which could exacerbate turbulence in the stadium.

Marsik added that another possible factor that could also increase the turbulence in the stadium would be the heat on the surface of the football field. If the temperature of the football field is warmer than the air above it, Marsik said the warm air will gradually rise. This will cause cold air from incoming wind currents to flow into the areas the warm air is leaving, ultimately causing greater wind flow.

Despite the difficulties of the experiment, Samson said he and his students hope to obtain concrete results from the information of their weather balloon and meteorological tower.

“Hopefully we can make some generalizations,” Samson said.

But even though Samson might not come with results this time, he plans on coming back next year with better experiments and more equipment.

Samson said it’s not really the results that really matter. “It’s the act of trying to experiment that went well.”12

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