1
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Pfannerstill EY, Arata C, Zhu Q, Schulze BC, Ward R, Woods R, Harkins C, Schwantes RH, Seinfeld JH, Bucholtz A, Cohen RC, Goldstein AH. Temperature-dependent emissions dominate aerosol and ozone formation in Los Angeles. Science 2024; 384:1324-1329. [PMID: 38900887 DOI: 10.1126/science.adg8204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/22/2024] [Indexed: 06/22/2024]
Abstract
Despite declines in transportation emissions, urban North America and Europe still face unhealthy air pollution levels. This has challenged conventional understanding of the sources of their volatile organic compound (VOC) precursors. Using airborne flux measurements to map emissions of a wide range of VOCs, we demonstrate that biogenic terpenoid emissions contribute ~60% of emitted VOC OH reactivity, ozone, and secondary organic aerosol formation potential in summertime Los Angeles and that this contribution strongly increases with temperature. This implies that control of nitrogen oxides is key to reducing ozone formation in Los Angeles. We also show some anthropogenic VOC emissions increase with temperature, which is an effect not represented in current inventories. Air pollution mitigation efforts must consider that climate warming will strongly change emission amounts and composition.
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Affiliation(s)
- Eva Y Pfannerstill
- Department of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley, CA, USA
| | - Caleb Arata
- Department of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley, CA, USA
| | - Qindan Zhu
- Department of Earth and Planetary Science, University of California at Berkeley, Berkeley, CA, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA
- NOAA Chemical Sciences Laboratory, Boulder, CO, USA
| | | | - Ryan Ward
- NOAA Chemical Sciences Laboratory, Boulder, CO, USA
| | - Roy Woods
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Colin Harkins
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA
- Department of Meteorology, Naval Postgraduate School, Monterey, CA, USA
| | | | | | - Anthony Bucholtz
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Ronald C Cohen
- Department of Earth and Planetary Science, University of California at Berkeley, Berkeley, CA, USA
- Department of Chemistry, University of California at Berkeley, Berkeley, CA, USA
| | - Allen H Goldstein
- Department of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley, CA, USA
- Department of Civil and Environmental Engineering, University of California at Berkeley, Berkeley, CA, USA
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2
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Gu S, Luo W, Charmchi A, McWhirter KJ, Rosenstiel T, Pankow J, Faiola CL. Limonene Enantiomeric Ratios from Anthropogenic and Biogenic Emission Sources. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2024; 11:130-135. [PMID: 38371653 PMCID: PMC10867824 DOI: 10.1021/acs.estlett.3c00794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/26/2024] [Accepted: 01/31/2024] [Indexed: 02/20/2024]
Abstract
Emissions from volatile chemical products (VCPs) have been identified as contributors to air quality degradation in urban areas. Limonene can be a tracer compound for VCPs containing fragrances in densely populated regions, but limonene is also emitted from conifers that are planted in urban areas. This creates challenges for using limonene to estimate VCP emissions. In this study, the -/+ enantiomeric ratios of limonene from VCP and conifer emission sources were quantified to evaluate if this measurement could be used to aid in source apportionment and emission inventory development. Samples were analyzed using a gas chromatograph equipped with a chiral column and mass spectrometry. The results demonstrate that limonene exhibits distinct enantiomeric ratios when sourced from VCPs versus conifers. (+)-Limonene was dominant in VCP sources (>97%), which was not universally true for conifer sources. The results were compared to those of air samples collected outside at two locations and indoors. The levels of (-)-limonene in outdoor air in Irvine and Portland and in indoor air were 50%, 22%, and 4%, respectively. This suggests outdoor limonene had both VCP and plant emission sources while indoor air was dominated by VCP sources. This study demonstrates the potential utility of enantiomeric analysis for improving VCP emission estimates in urban areas.
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Affiliation(s)
- Shan Gu
- Ecology
and Evolutionary Biology, University of
California Irvine, Irvine, California 92697, United States
| | - Wentai Luo
- Civil
and Environmental Engineering, Portland
State University, Portland, Oregon 97201, United States
| | - Avisa Charmchi
- Ecology
and Evolutionary Biology, University of
California Irvine, Irvine, California 92697, United States
- Chemistry, University
of California Irvine, Irvine, California 92697, United States
| | - Kevin J. McWhirter
- Civil
and Environmental Engineering, Portland
State University, Portland, Oregon 97201, United States
| | - Todd Rosenstiel
- Biology, Portland State University, Portland, Oregon 97201, United States
| | - James Pankow
- Civil
and Environmental Engineering, Portland
State University, Portland, Oregon 97201, United States
| | - Celia L. Faiola
- Ecology
and Evolutionary Biology, University of
California Irvine, Irvine, California 92697, United States
- Chemistry, University
of California Irvine, Irvine, California 92697, United States
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3
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Dolan RH, Wallington TJ, Anderson JE. Large Decreases in Tailpipe Criteria Pollutant Emissions from the U.S. Light-Duty Vehicle Fleet Expected in 2020-2040. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38323898 DOI: 10.1021/acs.est.3c04554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
The U.S. EPA MOVES3 model was used to assess the impact of the large-scale introduction of electric vehicles on emissions of criteria pollutants (CO, hydrocarbons [HC], NOx, and particulate matter [PM]) and CO2 from the U.S. light-duty vehicle fleet. Large reductions in emissions of these criteria pollutants occurred in 2000-2020. These trends are expected to continue through 2040 driven by turnover of the conventional fleet with old vehicles being replaced by battery electric vehicles (BEVs) and by new internal combustion engine vehicles (ICEVs) with modern emission control systems. Without the introduction of BEVs, the absolute emissions of CO, NOx, HC, and PM2.5 from the U.S. light-duty vehicle fleet are expected to decrease by approximately 61, 88, 55, and 20% from 2020 to 2040. Introduction of BEVs with market share increasing linearly to 100% in 2040 provides additional benefits, which, combined with ICEV fleet turnover, would lead to decreases of absolute emissions of CO, NOx, HC, and PM2.5 of approximately 77, 94, 71, and 37% from 2020 to 2040. Reductions in CO2 emissions follow a similar pattern. Large decreases in criteria pollutant and CO2 emissions from light duty vehicles lie ahead.
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Affiliation(s)
- Rachael H Dolan
- Ford Motor Company, Research & Advanced Engineering, Dearborn, Michigan 48121, United States
| | - Timothy J Wallington
- Center for Sustainable Systems, School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan 48019, United States
| | - James E Anderson
- Ford Motor Company, Research & Advanced Engineering, Dearborn, Michigan 48121, United States
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4
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Venter ZS, Hassani A, Stange E, Schneider P, Castell N. Reassessing the role of urban green space in air pollution control. Proc Natl Acad Sci U S A 2024; 121:e2306200121. [PMID: 38285938 PMCID: PMC10861851 DOI: 10.1073/pnas.2306200121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 12/14/2023] [Indexed: 01/31/2024] Open
Abstract
The assumption that vegetation improves air quality is prevalent in scientific, popular, and political discourse. However, experimental and modeling studies show the effect of green space on air pollutant concentrations in urban settings is highly variable and context specific. We revisited the link between vegetation and air quality using satellite-derived changes of urban green space and air pollutant concentrations from 2,615 established monitoring stations over Europe and the United States. Between 2010 and 2019, stations recorded declines in ambient NO2, (particulate matter) PM10, and PM2.5 (average of -3.14% y-1), but not O3 (+0.5% y-1), pointing to the general success of recent policy interventions to restrict anthropogenic emissions. The effect size of total green space on air pollution was weak and highly variable, particularly at the street scale (15 to 60 m radius) where vegetation can restrict ventilation. However, when isolating changes in tree cover, we found a negative association with air pollution at borough to city scales (120 to 16,000 m) particularly for O3 and PM. The effect of green space was smaller than the pollutant deposition and dispersion effects of meteorological drivers including precipitation, humidity, and wind speed. When averaged across spatial scales, a one SD increase in green space resulted in a 0.8% (95% CI: -3.5 to 2%) decline in air pollution. Our findings suggest that while urban greening may improve air quality at the borough-to-city scale, the impact is moderate and may have detrimental street-level effects depending on aerodynamic factors like vegetation type and urban form.
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Affiliation(s)
| | | | - Erik Stange
- Norwegian Institute for Nature Research, Oslo0855, Norway
| | - Philipp Schneider
- The Climate and Environmental Research Institute NILU, Kjeller2027, Norway
| | - Núria Castell
- The Climate and Environmental Research Institute NILU, Kjeller2027, Norway
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5
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Pfannerstill EY, Arata C, Zhu Q, Schulze BC, Woods R, Harkins C, Schwantes RH, McDonald BC, Seinfeld JH, Bucholtz A, Cohen RC, Goldstein AH. Comparison between Spatially Resolved Airborne Flux Measurements and Emission Inventories of Volatile Organic Compounds in Los Angeles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15533-15545. [PMID: 37791848 PMCID: PMC10586371 DOI: 10.1021/acs.est.3c03162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/05/2023]
Abstract
Los Angeles is a major hotspot for ozone and particulate matter air pollution in the United States. Ozone and PM2.5 in this region have not improved substantially for the past decade, despite a reduction in vehicular emissions of their precursors, NOx and volatile organic compounds (VOCs). This reduction in "traditional" sources has made the current emission mixture of air pollutant precursors more uncertain. To map and quantify emissions of a wide range of VOCs in this urban area, we performed airborne eddy covariance measurements with wavelet analysis. VOC fluxes measured include tracers for source categories, such as traffic, vegetation, and volatile chemical products (VCPs). Mass fluxes were dominated by oxygenated VOCs, with ethanol contributing ∼29% of the total. In terms of OH reactivity and aerosol formation potential, terpenoids contributed more than half. Observed fluxes were compared with two commonly used emission inventories: the California Air Resources Board inventory and the combination of the Biogenic Emission Inventory System with the Fuel-based Inventory of Vehicle Emissions combined with Volatile Chemical Products (FIVE-VCP). The comparison shows mismatches regarding the amount, spatial distribution, and weekend effects of observed VOC emissions with the inventories. The agreement was best for typical transportation related VOCs, while discrepancies were larger for biogenic and VCP-related VOCs.
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Affiliation(s)
- Eva Y. Pfannerstill
- Department
of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley 94720, California, United States
| | - Caleb Arata
- Department
of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley 94720, California, United States
| | - Qindan Zhu
- Department
of Earth and Planetary Science, University
of California at Berkeley, Berkeley 94720, California, United States
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder 80305, Colorado, United States
| | - Benjamin C. Schulze
- Department
of Environmental Science and Engineering, California Institute of Technology, Pasadena 91125, California, United States
| | - Roy Woods
- Department
of Meteorology, Naval Postgraduate School, Monterey 93943, California, United
States
| | - Colin Harkins
- Cooperative
Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder 80305, Colorado, United States
- NOAA Chemical
Sciences Laboratory, Boulder 80305, Colorado, United States
| | | | - Brian C. McDonald
- NOAA Chemical
Sciences Laboratory, Boulder 80305, Colorado, United States
| | - John H. Seinfeld
- Department
of Environmental Science and Engineering, California Institute of Technology, Pasadena 91125, California, United States
| | - Anthony Bucholtz
- Department
of Meteorology, Naval Postgraduate School, Monterey 93943, California, United
States
| | - Ronald C. Cohen
- Department
of Earth and Planetary Science, University
of California at Berkeley, Berkeley 94720, California, United States
- Department
of Chemistry, University of California at
Berkeley, Berkeley 94720, California, United States
| | - Allen H. Goldstein
- Department
of Environmental Science, Policy and Management, University of California at Berkeley, Berkeley 94720, California, United States
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6
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Cao C, Gentner DR, Commane R, Toledo-Crow R, Schiferl LD, Mak JE. Policy-Related Gains in Urban Air Quality May Be Offset by Increased Emissions in a Warming Climate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37327457 DOI: 10.1021/acs.est.2c05904] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Air quality policies have made substantial gains by reducing pollutant emissions from the transportation sector. In March 2020, New York City's activities were severely curtailed in response to the COVID-19 pandemic, resulting in 60-90% reductions in human activity. We continuously measured major volatile organic compounds (VOCs) during January-April 2020 and 2021 in Manhattan. Concentrations of many VOCs decreased significantly during the shutdown with variations in daily patterns reflective of human activity perturbations, resulting in a temporary ∼28% reduction in chemical reactivity. However, the limited effect of these dramatic measures was outweighed by larger increases in VOC-related reactivity during the anomalously warm spring 2021. This emphasizes the diminishing returns from transportation-focused policies alone and the risk of increased temperature-dependent emissions undermining policy-related gains in a warming climate.
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Affiliation(s)
- Cong Cao
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York 11794, United States
| | - Drew R Gentner
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States
| | - Róisín Commane
- Department of Earth and Environmental Sciences, Columbia University, New York, New York 10027, United States
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, United States
| | - Ricardo Toledo-Crow
- Advanced Science Research Center, City University of New York, New York, New York 10031, United States
| | - Luke D Schiferl
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, United States
| | - John E Mak
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York 11794, United States
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7
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Rahman MM, McConnell R, Schlaerth H, Ko J, Silva S, Lurmann FW, Palinkas L, Johnston J, Hurlburt M, Yin H, Ban-Weiss G, Garcia E. The Effects of Coexposure to Extremes of Heat and Particulate Air Pollution on Mortality in California: Implications for Climate Change. Am J Respir Crit Care Med 2022; 206:1117-1127. [PMID: 35727303 PMCID: PMC9704834 DOI: 10.1164/rccm.202204-0657oc] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 06/21/2022] [Indexed: 11/16/2022] Open
Abstract
Rationale: Extremes of heat and particulate air pollution threaten human health and are becoming more frequent because of climate change. Understanding the health impacts of coexposure to extreme heat and air pollution is urgent. Objectives: To estimate the association of acute coexposure to extreme heat and ambient fine particulate matter (PM2.5) with all-cause, cardiovascular, and respiratory mortality in California from 2014 to 2019. Methods: We used a case-crossover study design with time-stratified matching using conditional logistic regression to estimate mortality associations with acute coexposures to extreme heat and PM2.5. For each case day (date of death) and its control days, daily average PM2.5 and maximum and minimum temperatures were assigned (0- to 3-day lag) on the basis of the decedent's residence census tract. Measurements and Main Results: All-cause mortality risk increased 6.1% (95% confidence interval [CI], 4.1-8.1) on extreme maximum temperature-only days and 5.0% (95% CI, 3.0-8.0) on extreme PM2.5-only days, compared with nonextreme days. Risk increased by 21.0% (95% CI, 6.6-37.3) on days with exposure to both extreme maximum temperature and PM2.5. Increased risk of cardiovascular and respiratory mortality on extreme coexposure days was 29.9% (95% CI, 3.3-63.3) and 38.0% (95% CI, -12.5 to 117.7), respectively, and were more than the sum of individual effects of extreme temperature and PM2.5 only. A similar pattern was observed for coexposure to extreme PM2.5 and minimum temperature. Effect estimates were larger over age 75 years. Conclusions: Short-term exposure to extreme heat and air pollution alone were individually associated with increased risk of mortality, but their coexposure had larger effects beyond the sum of their individual effects.
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Affiliation(s)
| | - Rob McConnell
- Department of Population and Public Health Sciences, Keck School of Medicine
| | - Hannah Schlaerth
- Department of Civil and Environmental Engineering, Viterbi School of Engineering
| | - Joseph Ko
- Department of Civil and Environmental Engineering, Viterbi School of Engineering
| | | | | | - Lawrence Palinkas
- Department of Population and Public Health Sciences, Keck School of Medicine
- Suzanne Dworak Peck School of Social Work, and
| | - Jill Johnston
- Department of Population and Public Health Sciences, Keck School of Medicine
| | - Michael Hurlburt
- Department of Population and Public Health Sciences, Keck School of Medicine
- Suzanne Dworak Peck School of Social Work, and
| | - Hao Yin
- Department of Economics, University of Southern California, Los Angeles, California
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - George Ban-Weiss
- Department of Civil and Environmental Engineering, Viterbi School of Engineering
| | - Erika Garcia
- Department of Population and Public Health Sciences, Keck School of Medicine
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8
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Cohen RC. Thoughts on air quality when the world is electrified. Natl Sci Rev 2022; 9:nwac145. [PMID: 36128464 PMCID: PMC9477194 DOI: 10.1093/nsr/nwac145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Ronald C Cohen
- Departments of Chemistry and of Earth and Planetary Science, University of California , Berkeley , USA
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9
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Abstract
The past 60 years have seen large reductions in vehicle emissions of particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HCs), sulfur dioxide (SO2), and lead (Pb). Advanced emission after-treatment technologies have been developed for gasoline and diesel vehicles to meet increasingly stringent regulations, yielding absolute emission reductions from the on-road fleet despite increased vehicle miles traveled. As a result of reduced emissions from vehicles and other sources, the air quality in cities across the U.S. and Europe has improved greatly. Turn-over of the on-road fleet, increasingly stringent emission regulations (such as Tier 3 in the U.S., LEV III in California, Euro 6 in Europe, and upcoming rules in these same regions), and the large-scale introduction of electric vehicles will lead to even lower vehicle emissions and further improvements in air quality. We review historical vehicle emissions and air quality trends and discuss the future outlook.
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10
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Importance of ozone precursors information in modelling urban surface ozone variability using machine learning algorithm. Sci Rep 2022; 12:5646. [PMID: 35383223 PMCID: PMC8983660 DOI: 10.1038/s41598-022-09619-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/25/2022] [Indexed: 12/03/2022] Open
Abstract
Surface ozone (O\documentclass[12pt]{minimal}
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\begin{document}$$_3$$\end{document}3) is primarily formed through complex photo-chemical reactions in the atmosphere, which are non-linearly dependent on precursors. Even though, there have been many recent studies exploring the potential of machine learning (ML) in modeling surface ozone, the inclusion of limited available ozone precursors information has received little attention. The ML algorithm with in-situ NO information and meteorology explains 87% (R\documentclass[12pt]{minimal}
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\begin{document}$$^{2}$$\end{document}2 = 0.87) of the ozone variability over Munich, a German metropolitan area, which is 15% higher than a ML algorithm that considers only meteorology. The ML algorithm trained for the urban measurement station in Munich can also explain the ozone variability of the other three stations in the same city, with R\documentclass[12pt]{minimal}
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\begin{document}$$^{2}$$\end{document}2 = 0.88, 0.91, 0.63. While the same model robustly explains the ozone variability of two other German cities’ (Berlin and Hamburg) measurement stations, with R\documentclass[12pt]{minimal}
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\begin{document}$$^{2}$$\end{document}2 ranges from 0.72 to 0.84, giving confidence to use the ML algorithm trained for one location to other locations with sparse ozone measurements. The inclusion of satellite O\documentclass[12pt]{minimal}
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\begin{document}$$_3$$\end{document}3 precursors information has little effect on the ML model’s performance.
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11
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Simulation of the Air Quality in Southern California, USA in July and October of the Year 2018. ATMOSPHERE 2022. [DOI: 10.3390/atmos13040548] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A numerical investigation of the air quality in Southern California, USA in the year 2018 is presented using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). In July, a heat wave occurred, and in October, Santa Ana conditions prevailed; these conditions and their impact on air quality are the scope of the present numerical study.The high spatial resolution in the simulation includes two nested domains of 1 km and 3 km, respectively. Local climate zones land use categories are combined with the complex urban model building effect parameterization coupled with the building energy model (BEP+BEM) and the detailed MOZCART-T1 chemical reaction mechanism, which is the MOZART-T1 mechanism for trace gases with GOCART aerosols. Thus, the model is suitable to compare simulation results to in situ and satellite measurements of O3, NO2, CH4, and CO. The meteorology is captured well by the model. Comparison of simulation results with observations shows a good agreement of NO2 and ozone, whereas CO mixing ratios are generally underestimated. This hints at missing emissions in the 2017 National Emissions Inventory (NEI) dataset. Both the heat wave and the Santa Ana winds increase the air pollution with gas-phase species in Los Angeles. In both cases, nighttime boundary layer heights are small, which causes emissions to reside near the ground. During Santa Ana winds, NOx removal on aerosols is reduced. Methane mixing ratios are modeled very well at most stations in Los Angeles, but predictions of low emissions near the University of California cause inaccuracies at that location. Modeled and observed PM2.5 agree well on low-pollution days, but high-pollution events are generally missed by the model. During the heat wave, both modeled and observed PM2.5 concentrations exceed the recommended NAAQS National Ambient Air Quality Standards value of 12.5 g/m3. The present modeling approach serves as a base for the study and prediction of special weather events and their impact on air pollution.
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12
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Pennington EA, Seltzer KM, Murphy BN, Qin M, Seinfeld JH, Pye HO. Modeling secondary organic aerosol formation from volatile chemical products. ATMOSPHERIC CHEMISTRY AND PHYSICS 2021; 21:18247-18261. [PMID: 35087576 PMCID: PMC8788583 DOI: 10.5194/acp-21-18247-2021] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Volatile chemical products (VCPs) are commonly-used consumer and industrial items that are an important source of anthropogenic emissions. Organic compounds from VCPs evaporate on atmospherically relevant time scales and include many species that are secondary organic aerosol (SOA) precursors. However, the chemistry leading to SOA, particularly that of intermediate volatility organic compounds (IVOCs), has not been fully represented in regional-scale models such as the Community Multiscale Air Quality (CMAQ) model, which tend to underpredict SOA concentrations in urban areas. Here we develop a model to represent SOA formation from VCP emissions. The model incorporates a new VCP emissions inventory and employs three new classes of emissions: siloxanes, oxygenated IVOCs, and nonoxygenated IVOCs. VCPs are estimated to produce 1.67 μg m-3 of noontime SOA, doubling the current model predictions and reducing the SOA mass concentration bias from -75% to -58% when compared to observations in Los Angeles in 2010. While oxygenated and nonoxygenated intermediate volatility VCP species are emitted in similar quantities, SOA formation is dominated by the nonoxygenated IVOCs. Formaldehyde and SOA show similar relationships to temperature and bias signatures indicating common sources and/or chemistry. This work suggests that VCPs contribute up to half of anthropogenic SOA in Los Angeles and models must better represent SOA precursors from VCPs to predict the urban enhancement of SOA.
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Affiliation(s)
- Elyse A. Pennington
- Oak Ridge Institute for Science and Education Fellow in the Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
- Department of Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Karl M. Seltzer
- Oak Ridge Institute for Science and Education Fellow in the Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Benjamin N. Murphy
- Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
| | - Momei Qin
- Oak Ridge Institute for Science and Education Fellow in the Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, China
| | - John H. Seinfeld
- Department of Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Havala O.T. Pye
- Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711
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