Atmospheric Chemistry and Physics (May 2024)
A better representation of volatile organic compound chemistry in WRF-Chem and its impact on ozone over Los Angeles
- Q. Zhu,
- Q. Zhu,
- Q. Zhu,
- R. H. Schwantes,
- M. Coggon,
- C. Harkins,
- C. Harkins,
- J. Schnell,
- J. Schnell,
- J. He,
- J. He,
- H. O. T. Pye,
- M. Li,
- B. Baker,
- Z. Moon,
- Z. Moon,
- R. Ahmadov,
- E. Y. Pfannerstill,
- E. Y. Pfannerstill,
- B. Place,
- P. Wooldridge,
- B. C. Schulze,
- C. Arata,
- A. Bucholtz,
- J. H. Seinfeld,
- C. Warneke,
- C. E. Stockwell,
- L. Xu,
- L. Xu,
- L. Xu,
- K. Zuraski,
- K. Zuraski,
- M. A. Robinson,
- M. A. Robinson,
- J. A. Neuman,
- P. R. Veres,
- P. R. Veres,
- J. Peischl,
- J. Peischl,
- S. S. Brown,
- S. S. Brown,
- A. H. Goldstein,
- A. H. Goldstein,
- R. C. Cohen,
- R. C. Cohen,
- B. C. McDonald
Affiliations
- Q. Zhu
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- Q. Zhu
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- Q. Zhu
- now at: Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02319, USA
- R. H. Schwantes
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- M. Coggon
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- C. Harkins
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- C. Harkins
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- J. Schnell
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- J. Schnell
- NOAA Global Systems Laboratory, Boulder, CO 80305, USA
- J. He
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- J. He
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- H. O. T. Pye
- Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
- M. Li
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- B. Baker
- NOAA Air Resources Laboratory, College Park, MD 20740, USA
- Z. Moon
- NOAA Air Resources Laboratory, College Park, MD 20740, USA
- Z. Moon
- Earth Resources Technology (ERT), Inc., Laurel, MD 20707, USA
- R. Ahmadov
- NOAA Global Systems Laboratory, Boulder, CO 80305, USA
- E. Y. Pfannerstill
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA 94720, USA
- E. Y. Pfannerstill
- now at: Institute for Energy and Climate Research 8: Troposphere, Forschungszentrum Jülich, 52425 Jülich, Germany
- B. Place
- Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
- P. Wooldridge
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- B. C. Schulze
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA 91125, USA
- C. Arata
- Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
- A. Bucholtz
- Department of Meteorology, Naval Postgraduate School, Monterey, CA 93943, USA
- J. H. Seinfeld
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA 91125, USA
- C. Warneke
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- C. E. Stockwell
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- L. Xu
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- L. Xu
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- L. Xu
- now at: Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MI 63130, USA
- K. Zuraski
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- K. Zuraski
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- M. A. Robinson
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- M. A. Robinson
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- J. A. Neuman
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- P. R. Veres
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- P. R. Veres
- now at: Research Aviation Facility, National Center for Atmospheric Research, Boulder, CO 80301, USA
- J. Peischl
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- J. Peischl
- Cooperative Institute for Research in Environmental Sciences – University of Colorado, Boulder, CO 80309, USA
- S. S. Brown
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- S. S. Brown
- Department of Chemistry, University of Colorado, Boulder, Boulder, CO 80309, USA
- A. H. Goldstein
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA 94720, USA
- A. H. Goldstein
- Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
- R. C. Cohen
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- R. C. Cohen
- Department of Earth and Planetary Sciences, University of California, Berkeley, Berkeley, CA 94720, USA
- B. C. McDonald
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305, USA
- DOI
- https://doi.org/10.5194/acp-24-5265-2024
- Journal volume & issue
-
Vol. 24
pp. 5265 – 5286
Abstract
The declining trend in vehicle emissions has underscored the growing significance of volatile organic compound (VOC) emissions from volatile chemical products (VCPs). However, accurately representing VOC chemistry in simplified chemical mechanisms remains challenging due to its chemical complexity including speciation and reactivity. Previous studies have predominantly focused on VOCs from fossil fuel sources, leading to an underrepresentation of VOC chemistry from VCP sources. We developed an integrated chemical mechanism, RACM2B-VCP, that is compatible with WRF-Chem and is aimed at enhancing the representation of VOC chemistry, particularly from VCP sources, within the present urban environment. Evaluation against the Air Quality System (AQS) network data demonstrates that our model configured with RACM2B-VCP reproduces both the magnitude and spatial variability of O3 and PM2.5 in Los Angeles. Furthermore, evaluation against comprehensive measurements of O3 and PM2.5 precursors from the Reevaluating the Chemistry of Air Pollutants in California (RECAP-CA) airborne campaign and the Southwest Urban NOx and VOC Experiment (SUNVEx) ground site and mobile laboratory campaign confirm the model's accuracy in representing NOx and many VOCs and highlight remaining biases. Although there exists an underprediction in the total VOC reactivity of observed VOC species, our model with RACM2B-VCP exhibits good agreement for VOC markers emitted from different sectors, including biogenic, fossil fuel, and VCP sources. Through sensitivity analyses, we probe the contributions of VCP and fossil fuel emissions to total VOC reactivity and O3. Our results reveal that 52 % of the VOC reactivity and 35 % of the local enhancement of MDA8 O3 arise from anthropogenic VOC emissions in Los Angeles. Significantly, over 50 % of this anthropogenic fraction of either VOC reactivity or O3 is attributed to VCP emissions. The RACM2B-VCP mechanism created, described, and evaluated in this work is ideally suited for accurately representing ozone for the right reasons in the present urban environment where mobile, biogenic, and VCP VOCs are all important contributors to ozone formation.
