Ozone Science

LADCO works to understand the causes of ground level ozone pollution, also known as smog, in the Great Lakes region. This page provides the state of the science information on ozone chemistry, sources, and mitigation strategies.

On this page: Ozone Conceptual Model, Ozone Chemistry Report

Overarching question: How can the LADCO member states with ozone pollution issues most effectively address these issues?

Overall goal: Provide LADCO member states with the technical information needed to design cost-effective emissions control strategies to reduce ozone concentrations. This goal includes providing information about ozone precursor control measures, and the anticipated ozone impacts from implementation of those control measures.

Conceptual Models of Ozone Formation

In late 2022/early 2023, Dr. Angie Dickens, the LADCO Data Scientist, expanded on the work by our Summer 2021 intern to develop a comprehensive report on ozone conceptual models for all of the ozone nonattainment and maintenance areas in the region.

Technical Report: Conceptual Models of Ozone Formation in the LADCO Region

Overview of the report: This report compiles previously released and published information, along with some new analyses by LADCO, to provide an overview of ozone formation and distribution mechanisms in the LADCO region. The report first looks at the different drivers of ozone formation (meteorology, transport, ozone precursors, and ozone formation chemistry) and evaluates their roles around the region. It then examines trends in ozone concentrations and evaluates how the different drives contribute to these trends. The report finally presents free-standing conceptual models for each nonattainment and maintenance area in the region.

Ozone Chemistry

In late 2021 to 2022, Dr. Angie Dickens, the LADCO Data Scientist, conducted a meta-analysis of recent research on the current state of ground-level ozone formation chemistry in the Great Lakes region. She combined findings from field campaigns, observational studies, and modeling research with original analyses conducted at LADCO to provide the most comprehensive interpretation to date of the causes of and solutions to ozone pollution in this region.

Technical Report: Ozone Formation Sensitivity to NOx and VOC Emissions in the LADCO Region

Overview of the report: This report applies a suite of analytical tools to air quality data in the Great Lakes region to determine whether ozone formation in the region is most sensitive to NOx- or VOC-emissions changes. The report also examines how the ozone-NOx-VOC chemistry has changed over the past decades.

The report examines different approaches to understand the chemical conditions of ozone formation at different locations in this region. The first three approaches involve the use of molecular ratios as indicators of the ozone formation chemistry, with certain ranges of ratio values indicating NOx-sensitive, transitional, or VOC-sensitive ozone chemistry. The second two approaches use patterns in ozone concentrations to infer the ozone formation chemistry. All analyses in the report focus on the ozone formation chemistry on high-ozone days.