Grantee Research Project Results
2021 Progress Report: Evaluating chemical mechanisms with recent field data to account for the contributions of volatile chemical product emissions to urban ozone pollution
EPA Grant Number: R840010Title: Evaluating chemical mechanisms with recent field data to account for the contributions of volatile chemical product emissions to urban ozone pollution
Investigators: Stockwell, Chelsea , McDonald, Brian , Gkatzelis, Georgios , Coggon, Matthew , Li, Meng , Schwantes, Rebecca
Current Investigators: Bates, Kelvin , Li, Meng , Stockwell, Chelsea , McDonald, Brian , Coggon, Matthew , Schwantes, Rebecca
Institution: University of Colorado at Boulder , NOAA Earth System Research Laboratories
EPA Project Officer: Chung, Serena
Project Period: August 1, 2020 through July 31, 2023 (Extended to April 30, 2024)
Project Period Covered by this Report: August 1, 2020 through July 31,2021
Project Amount: $396,135
RFA: Chemical Mechanisms to Address New Challenges in Air Quality Modeling (2019) RFA Text | Recipients Lists
Research Category: Early Career Awards , Air , Air Quality and Air Toxics
Objective:
The objective of this research is to improve the representation of reactions that describe the chemical oxidation of volatile chemical product (VCP) emissions in urban air quality models. The objectives for Year 1 were to identify key components of VCP emissions that are misrepresented in modern chemical mechanisms, assess the impact of fragrances on the urban VOC burden, and incorporate the chemistry of key VCP emissions into the Master Chemical Mechanism (MCM).
Progress Summary:
This work has determined that alcohols, glycols, and glycol ethers are key VCP components that are misrepresented in modern chemical mechanisms. To date, degradation schemes for glycerol and tetrahydrofuran have been included into the MCM, while the incorporation of mechanisms for lesser abundant oxygenates is ongoing. Furthermore, we have leveraged our measurements in NYC to show that fragranced VCPs emit monoterpenes to the urban atmosphere at significant rates, and that the composition and reactivity of fragrances detected in urban air generally matches those measured from fragranced VCPs. This work is a significant step towards developing models that account for the emissions and reactivity of key VCP emissions, and addressing request for applications (RFA) Research Areas 1 and 3.
Beyond this work, we have incorporated chemical degradation schemes for oxygenated VCPs (oVCPs) into the NOAA ESRL version of the Regional Atmospheric Chemistry Mechanism (RACM-ESRL). WRF-Chem sensitivity analyses demonstrate the important role of VCPs and oxygenated VOC chemistry on the formation of peroxy acyl nitrates (PANs), which are important oxidation products that modulate ozone formation on regional scales. This work is an important step forward towards developing condensed mechanisms that can be used to study key chemical processes in urban environments, and addressing the objectives of RFA Research Area 3.
The work described above was recently published in a peer-reviewed manuscript (Coggon et al. 2021). The results from this manuscript have informed the direction of our work for Year 2, which includes identifying key secondary species, such as PANs, formed as a result of VCP oxidation.
Future Activities:
In the upcoming year, we plan to continue our work to evaluate VCP emissions with field observations, with a special focus on quantifying glycol emissions. This work is an important step in identifying the chemistry missing from modern mechanisms, and addresses RFA Research Area 1.
We plan to use our modified box models to search for tracers of VCP oxidation in our ambient datasets. This analysis includes our NYC dataset, but will also focus on data collected in Los Angeles as part of the SUNVEx and RECAP-CA campaigns. This step is important in evaluating the performance of our models against ambient measurements, and addresses RFA Research Area 3.
To date, our updates to reduced chemical mechanisms focused on RACM-ESRL. We plan to apply our updates to RACM2_Berkeley2 and incorporate this mechanism into our WRF-Chem simulations. We plan to evaluate this updated mechanism (termed RACM2-Berkeley2_VCP) against available datasets, including urban measurements conducted by aircraft during the FIREX-AQ field campaign.
References:
Coggon, M. M., Gkatzelis, G. I., McDonald, B. C., Gilman, J. B., Schwantes, R. H., Abuhassan, N., Aikin, K. C., Arend, M. F., Berkoff, T. A., Brown, S. S., Campos, T. L., Dickerson, R. R., Gronoff, G., Hurley, J. F., Isaacman-VanWertz, G., Koss, A. R., Li, M., McKeen, S. A., Moshary, F., Peischl, J., Pospisilova, V., Ren, X., Wilson, A., Wu, Y., Trainer, M., and Warneke, C.: Volatile chemical product emissions enhance ozone and modulate urban chemistry, Proceedings of the National Academy of Sciences, 118, https://doi.org/10.1073/pnas.2026653118, 2021.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 11 publications | 6 publications in selected types | All 6 journal articles |
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Type | Citation | ||
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Coggon MM, Gkatzelis GI, McDonald BC, Gilman JB, Schwantes RH, Abuhassan N, Aikin KC, Arend MF, Berkoff TA, Brown SS, Campos TL, Dickerson RR, Gronoff G, Hurley JF, Isaacman-VanWertz G, Koss AR, et al. Volatile chemical product emissions enhance ozone and modulate urban chemistry. Proceedings of the National Academy of Sciences 2021;118. |
R840010 (2021) |
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Supplemental Keywords:
Urban ozone, peroxy acyl nitratesRelevant Websites:
Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA)
Southwest Urban NOx and VOC Experiment
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.