Clearer View of Great Lakes Air Quality

Clearer View of Great Lakes Air Quality

The complex lake and land breezes and the atmospheric pressure differences across the Great Lakes region of North America can result in high levels of ozone pollution that are difficult to monitor or predict. Recently, air quality experts began incorporating more satellite data and customized models from NASA to better track that pollution. Their goal is to better inform local decision-making about how to improve air quality.

Federal air quality standards aim to protect the public from unhealthy levels of ground-level ozone, among other pollutants. Those most at risk include children (as their lungs are still developing); elderly populations; individuals with existing lung conditions; and people who are active outdoors. When air pollution levels exceed the standards set by the Environmental Protection Agency (EPA), they can aggravate lung diseases such as emphysema and chronic bronchitis, while increasing the frequency of asthma attacks.

Recently the Lake Michigan Air Directors Consortium (LADCO) and the Wisconsin Department of Natural Resources teamed with NASA researchers to improve the accuracy and spatial resolution of air quality assessments for Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin. Their goal was to integrate more datasets while developing finer-scale models for how ozone circulates in the region.

The map above shows predicted ozone concentrations around Lake Michigan on June 2, 2017, a high-ozone day that was identified during NASA’s Lake Michigan Ozone Study.

“Previously, LADCO was doing air quality simulations with the Environmental Protection Agency at 12-kilometer-resolution,” said Brad Pierce, a member of the NASA-funded Health and Air Quality Applied Sciences Team (HAQAST). “We were able to improve that resolution, bringing it up to 1.3 kilometers and increasing the accuracy of the simulations by more than 30 percent.”

Creating models that correctly represent the unique weather along Lake Michigan’s shores is no easy task, noted Zac Adelman, executive director of LADCO. Ground-level ozone is created when pollutants that emanate from cars, trucks, and fossil-fueled power plants interact with sunlight. Differences in nearby water and air temperatures, onshore and offshore winds, and atmospheric pressure can concentrate this ozone and other pollutants in localized pockets.

“We tested many different surface data sets from NASA and NOAA to figure out how we can combine them to produce the most accurate estimate of meteorological conditions that influence these ozone concentrations,” said Jason Otkin, principal investigator for the project and an associate scientist at the University of Wisconsin-Madison.

NASA satellites, such as Terra and Aqua, provide standardized satellite measurements of environmental variables such as lake surface temperature and vegetation. These data complement wind and weather observations from NOAA and ground-based pollution monitoring from EPA and state agencies. The research team also added data on soil moisture and land surface temperature from NASA’s Land Information System and the Short-term Prediction Research and Transition Center (SPoRT), which integrates data from NASA’s Soil Moisture Active Passive (SMAP) mission and NOAA’s GOES series of satellites.

By working directly with the end users, the HAQAST team customized and refined ozone models for the region based on feedback and real-time ground observations from LADCO staff. “The most effective partnerships are those where you’re not just throwing something over the fence, but you work with the user, incorporate their feedback, and actually give them a fully operational tool that’s really customized for their needs,” said Pierce. “That’s what we were able to do here.”

NASA Earth Observatory image by Lauren Dauphin, using data from R. Bradley Pierce on behalf of the Lake Michigan Ozone Study project. Story by Lia Poteet, NASA Earth Applied Sciences, with Mike Carlowicz.

References & Resources