Articles | Volume 4, issue 2
https://doi.org/10.5194/ar-4-517-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/ar-4-517-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
30 Oct 2026
Research article |
| 30 Oct 2026
| 30 Oct 2026
Measurements and modeling of urban secondary organic aerosol formation potential as a function of precursor volatility class in the Los Angeles area during summer 2022
Melissa A. Ehrenfels
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Benjamin C. Schulze
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
currently at: Bain & Company, Denver, CO 80202, USA
Andrew R. Jensen
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
currently at: Currently at Department of Chemistry and Biochemistry, Kalamazoo College, Kalamazoo, MI 49006, USA
Afsara Tasnia
Department of Chemical & Environmental Engineering, Center for Environmental Research & Technology, University of California-Riverside, Riverside, CA 92521, USA
currently at: South Coast Air Quality Management District, Diamond Bar, CA 91765, USA
Douglas A. Day
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Pedro Campuzano-Jost
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Anne V. Handschy
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Melinda K. Schueneman
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
currently at: Office of Applied Science and Environmental Solutions, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
Seonsik Yun
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Dongwook Kim
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Donna Sueper
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Aerodyne Research Inc., Billerica, MA 01821, USA
Havala O. T. Pye
Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
currently at: Office of Applied Science and Environmental Solutions, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
Benjamin N. Murphy
Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
currently at: Norwegian Meteorological Institute, 0371 Oslo, Norway
T. Nash Skipper
Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
currently at: Office of Air and Radiation, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
Drew B. Blauth
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Kelley C. Barsanti
Department of Chemical & Environmental Engineering, Center for Environmental Research & Technology, University of California-Riverside, Riverside, CA 92521, USA
currently at: NSF National Center for Atmospheric Research, Boulder, CO 80305, USA
Joost A. de Gouw
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Jose L. Jimenez
CORRESPONDING AUTHOR
Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309, USA
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
Data sets
CMAQ-CRACMM2 predictions for Summer 2019 in Los Angeles, CA (v1) U.S. Environmental Protection Agency https://doi.org/10.23719/d-73nn
Model code and software
CMAQ (Version 5.5) US EPA Office of Research and Development https://doi.org/10.5281/zenodo.13883210
Models for the publication: Measurements and modeling of urban secondary organic aerosol formation potential as a function of precursor volatility class in the Los Angeles area during summer 2022 Melissa Ehrenfels https://doi.org/10.5281/zenodo.22923435
Short summary
Los Angeles, CA, suffers from poor air quality, partially due to secondary aerosol formation. The identity and sources of the most important gas-phase precursors are complex and unresolved issues. For the first time, we separated ambient gas-phase species by volatility, then measured their potential to form aerosols. We found that higher-volatility emissions are responsible for 2/3 of the aerosol formation and lower-volatility ones for 1/3. We evaluate two box models against our measurements.
Los Angeles, CA, suffers from poor air quality, partially due to secondary aerosol formation....
Altmetrics
Final-revised paper
Preprint