Evaluating Surface Ozone Sensitivity to Emissions Changes in the Great Lakes Region

The objective of this project was to quantify the surface ozone changes from reducing the emissions of NOx or VOCs from different inventory sectors and further use those information to achieve the goal of identifying optimal ozone reduction strategies for key receptor areas in the LADCO region. The project answered the following four questions: 

  1. How do ozone concentrations at a receptor change when total NOx, VOC, or NOx and VOC emissions are reduced along a spectrum of 10% to 100% reduction? 

2. Expanding on Question 1, rather than looking at total NOx, VOC, or NOx and VOC emissions reductions, how do ozone concentrations at a receptor change when emissions are reduced from onroad mobile gasoline vehicles, onroad mobile diesel vehicles, nonroad mobile, volatile chemical products, other nonpoint, electricity generation point, or non-electricity point sources? 

3. Which combination(s) of NOx, VOC, and inventory sector has the largest impact (reduction) on peak ozone formation periods in each receptor area? 

4. What are the periods in the diel within which sectorized emissions reductions have the largest impact on mitigating daily peak ozone concentrations during ozone exceedance days? In other words, emissions reductions from which sectors and when have the largest impact on mitigating ozone exceedances in each receptor? 

The project used a gridded, regional-scale air quality model, the Comprehensive Air Quality Model with Extensions (CAMx), equipped with the High-order Decoupled Direct Method (HDDM) tool to simulate the changes in ozone from reducing ozone precursor emissions in the LADCO region. Analysis of the changes in ozone concentrations focused on counties in 2015 ozone NAAQS nonattainment and maintenance areas in the LADCO region. 

The following table links to the project deliverables.

1Final Workplan (PDF)9/2/20
1Modeling Protocol (PDF)9/2/20
2Final Project Presentation: Slides | Recording5/12/22
3Final Report5/31/22

Please send questions about these reports to Zac Adelman.