Strengths and Limitations of Current Tools to Characterize Background Ozone

• By: AWMA
• On: 11/17/2020 15:29:17
• In: EM Articles
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by Heather Simon and Golam Sarwar

A key aspect of air quality management is identifying the driving sources of air pollution. In the United States, the U.S. Environmental Protection Agency (EPA) uses the concept of “background ozone” to describe ozone (O₃) coming from sources other than anthropogenic emissions of O₃ precursors. EPA has identified provisions in the U.S. Clean Air Act that provide regulatory relief to local jurisdictions that are unduly impacted by background O₃. Each of these provisions relies on technical tools—including photochemical models, monitors, satellite data, and ozonesondes—to accurately quantify O₃ originating from controllable, anthropogenic sources versus background O₃. The articles in this month's EM explore the strengths and limitations of current tools used to quantify background O₃.

To begin, Hogrefe, et al. delve into the details of air quality models that are critical for characterizing source contributions to O₃ concentrations at different locations across the United States. Second, Neu, et al. describe how satellite data are being used to inform air quality models. Next, Stauffer, et al. couple statistical analysis of zonesonde measurements at Trinidad Head, CA, with routine O₃ surface monitors in California, satellite-derived carbon monoxide surfaces, and meteorology data. Finally, Jaffe, et al. describe the uncertainties associated with each of the tools addressed in the other three articles and identify the need for targeted investment to address current shortcomings.

Continue reading the full November 2020 issue of EM.