Ozone Production Efficiencies in the Three Largest United States Cities from Airborne Measurements

Despite ongoing reductions in emissions of ozone (O<sub>3</sub>) precursors, nitrogen oxides (NO<sub><i>x</i></sub> = NO + NO<sub>2</sub>) and volatile organic compounds (VOCs), the three largest urban areas in the United States ─ New York City (NYC), Chicago, and Los Angeles (LA) ─ continue to exceed national air quality standards for O<sub>3</sub>. Airborne measurements during the 2023 Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) campaign investigated nonlinear O<sub>3</sub> photochemistry in these cities. We report mean ozone production efficiency (OPE), the enhancement ratio of O<sub><i>x</i></sub> (= O<sub>3</sub> + NO<sub>2</sub>) to NO<sub><i>x</i></sub> oxidation products, of 9 ± 4 (1σ), 6 ± 3, and 6 ± 3 ppbv ppbv<sup>-1</sup> in NYC, Chicago, and LA, respectively. Compared to historical values, OPE has increased in NYC but remains constant in LA. We find that OPE during AEROMMA has a nonlinear, inverse relationship with total reactive nitrogen (NO<sub><i>y</i></sub>, a proxy for initial NO<sub><i>x</i></sub>) and a positive correlation with the nonmethane VOC to NO<sub><i>y</i></sub> enhancement ratio. A zero-dimensional photochemical model supports these observed OPE dependences on NO<sub><i>x</i></sub> and VOCs and shows that OPE is a distinct metric from total O<sub>3</sub> production that is informative to the development of O<sub>3</sub> pollution control strategies. We find that OPE values have higher variability, and a larger increase with NO<sub><i>x</i></sub> emissions reductions, in areas that experience NO<sub><i>x</i></sub>-sensitive rather than NO<sub><i>x</i></sub>-saturated O<sub>3</sub> photochemistry; nonetheless, NO<sub><i>x</i></sub> reductions under NO<sub><i>x</i></sub>-sensitive conditions still reduce total O<sub>3</sub> production despite the corresponding increase in OPE.

Authors

Institutions

Publication Details

Journal
Environmental Science & Technology
Published
2025-06-24
DOI
https://doi.org/10.1021/acs.est.5c02073
Citations
6
Primary Topic
Atmospheric chemistry and aerosols
Type
article
Field-Weighted Citation Impact
7.80

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

Ozone Production Efficiencies in the Three Largest United States Cities from Airborne Measurements

Lu Xu, C. Warneke, Birger Bohn, Michael A. Robinson et al.
6 citations
Environmental Science & Technology
Atmospheric chemistry and aerosols
7.80
article

Ozone Production Efficiencies in the Three Largest United States Cities from Airborne Measurements

Lu Xu, C. Warneke, Birger Bohn, Michael A. Robinson, Chelsea E. Stockwell, Jessica B. Gilman, Victoria Treadaway, John D. Crounse, Kelvin H. Bates, Gordon A. Novak, Matthew Mitchell Coggon, Kristen Zuraski, Wyndom S. Chace, Aaron Stainsby, Glenn M. Wolfe, Rose D. Taylor, Nell B. Schafer, Jeff Peischl, Hendrik Fuchs, Paul O. Wennberg, Anna Novelli, Andrew W. Rollins, Patrick R. Veres, Steven S. S Brown, Georgios I. Gkatzelis, Morgan Selby, I. B. Pollack, Christopher M. Jernigan, Caroline C. Womack, Rebecca H. Schwantes, Eleanor M. Waxman, Katherine Ball
article en
6 citations

Abstract

Despite ongoing reductions in emissions of ozone (O<sub>3</sub>) precursors, nitrogen oxides (NO<sub><i>x</i></sub> = NO + NO<sub>2</sub>) and volatile organic compounds (VOCs), the three largest urban areas in the United States ─ New York City (NYC), Chicago, and Los Angeles (LA) ─ continue to exceed national air quality standards for O<sub>3</sub>. Airborne measurements during the 2023 Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) campaign investigated nonlinear O<sub>3</sub> photochemistry in these cities. We report mean ozone production efficiency (OPE), the enhancement ratio of O<sub><i>x</i></sub> (= O<sub>3</sub> + NO<sub>2</sub>) to NO<sub><i>x</i></sub> oxidation products, of 9 ± 4 (1σ), 6 ± 3, and 6 ± 3 ppbv ppbv<sup>-1</sup> in NYC, Chicago, and LA, respectively. Compared to historical values, OPE has increased in NYC but remains constant in LA. We find that OPE during AEROMMA has a nonlinear, inverse relationship with total reactive nitrogen (NO<sub><i>y</i></sub>, a proxy for initial NO<sub><i>x</i></sub>) and a positive correlation with the nonmethane VOC to NO<sub><i>y</i></sub> enhancement ratio. A zero-dimensional photochemical model supports these observed OPE dependences on NO<sub><i>x</i></sub> and VOCs and shows that OPE is a distinct metric from total O<sub>3</sub> production that is informative to the development of O<sub>3</sub> pollution control strategies. We find that OPE values have higher variability, and a larger increase with NO<sub><i>x</i></sub> emissions reductions, in areas that experience NO<sub><i>x</i></sub>-sensitive rather than NO<sub><i>x</i></sub>-saturated O<sub>3</sub> photochemistry; nonetheless, NO<sub><i>x</i></sub> reductions under NO<sub><i>x</i></sub>-sensitive conditions still reduce total O<sub>3</sub> production despite the corresponding increase in OPE.

Environmental Science & TechnologyVol. 59(26)
California Institute of Technology (US), Planetary Science Institute (US), Goddard Space Flight Center (US), Cooperative Institute for Research in Environmental Sciences (US), Forschungszentrum Jülich (DE), University of Cologne (DE), University of Colorado Boulder (US), University of Colorado System (US), Division of Chemistry (US), NOAA Chemical Sciences Laboratory (US), University of Maryland, Baltimore County (US)
Klaus Tschira Stiftung, National Oceanic and Atmospheric Administration, European Research Council
Openalex Percentile: Top 2%
Atmospheric chemistry and aerosols
7.80
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.