Valparaiso Researchers Discover Midnight Ozone Spikes

Valparaiso University researchers discovered elevated ground-level ozone between midnight and 2 a.m., contradicting the expected pattern of peak ozone during afternoon sunlight hours.

Ground-level ozone forms smog and causes respiratory health problems, according to the American Lung Association. The midnight timing prompted Katelyn Barber, an assistant professor in the geology, meteorology and environmental sciences department, and environmental science major Lynne Thissen to investigate further.

"That's pretty unusual when you think about the mechanisms of ozone," Barber said. "It should be tied more closely to the sun cycle—with your highest concentration at 5 or 6 p.m."

The team monitors ozone levels using the Valparaiso University Ozone Garden, where ozone-sensitive plants like snap beans and milkweed grow alongside resistant varieties. Plant damage signals elevated ozone levels.

Thissen is examining whether the spikes originate locally or from nearby regions. "Even three miles up the road, we're not seeing the same result," she said.

Chris Iceman, an associate professor of chemistry, has deployed purple air sensors across the region with students. Spring Break Service Trips also installed new air quality sensors in Chicago and northwest Indiana. Both projects provide data for the ozone study.

Barber has been accepted to the Department of Energy's Summer Visiting Faculty Program to expand the research. She and Thissen plan to complete their report by late July.