EPA Research Partner Support Story: Lake Michigan’s ozone formation and transport
Partners: Wisconsin Department of Natural Resources (DNR), Lake Michigan Air Directors Consortium (LADCO)
Challenge: Better understanding ozone formation and transport impacting the shorelines of Lake Michigan
Resource: Advanced air quality monitoring methods deployed at various sites across Lake Michigan’s western shorelines, including on-board federal research vessel in collaboration with the National Oceanic and Atmospheric Administration (NOAA) and research groups at NASA, the University of Iowa, the University of Northern Iowa, the University of Minnesota, the University of Wisconsin via the National Science Foundation, and the Electric Power Research Institute (EPRI)
Project Period: 2017 – 2022
Ozone is formed when compounds such as nitrogen oxides (NOx) and volatile organic compounds (VOCs) react with sunlight. Despite dramatic reductions in these ozone precursor emissions, many areas bordering Lake Michigan continue to experience elevated ozone concentrations. This long-standing issue is one of the more challenging air quality issues in the eastern US.
“This study will improve the models that we use to inform science-based decision making.” – Wisconsin DNR Pat Stevens (former Assistant Deputy Secretary and Environmental Management Division Administrator)
A problem that is hindering states and stakeholders addressing this challenge is associated with the formation of ozone over Lake Michigan and the complex interaction of the meteorology and ozone chemistry, including the transport of ozone and ozone precursors in the region, which are not completely understood. Photochemical models are important tools for understanding such transport issues. However, these models historically have been unable to reproduce the lake breeze effect present around Lake Michigan, making it difficult for states, LADCO and EPA to accurately predict and address ozone concentrations along the Lake Michigan lakeshore. LADCO is a regional planning organization that includes representation from Illinois, Indiana, Michigan, Minnesota, Ohio and Wisconsin
In the summer of 2017, EPA ORD, LADCO, academic and private institutions, and other state and federal agencies pooled their expertise and resources to commence the Lake Michigan Ozone Study (LMOS-2017). Under LMOS, EPA worked with partners to collect information that continues to be used to better inform air quality models and improve the scientific understanding of ozone formation around Lake Michigan. EPA ORD, in conjunction with NOAA and NASA, outfitted a NOAA research vessel with EPA instruments to support over-the-water measurements. NASA and EPRI provided airborne remote sensing measurement to complement EPA and state surface measurements to help understand pollutant transport over Lake Michigan. These measurements will be combined with satellite data have been used by EPA and other researchers to better understand ozone chemistry and transport over the area, and better inform efforts to reduce ozone formation along the shoreline.
All LMOS data have been posted in a public archive (archive), and the science team published early results of the study in an April 2019 synthesis report. The LMOS data sets have been used to support at least a dozen peer reviewed publications, which include numerous modeling studies are being conducted by external collaborators and by EPA’s Office of Air Quality Planning and Standards and Region 5, including a recent publication assessing WFR-CMAQ model performance.