Space-Based Observations of Ozone Precursors within California Wildfire Plumes and the Impacts on Ozone-NO_x-VOC Chemistry

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(39), P. 14648 - 14660

Published: Sept. 13, 2023

The frequency of wildfires in the western United States has escalated recent decades. Here we examine impacts on ground-level ozone (O3) precursors and O3-NOx-VOC chemistry from source to downwind urban areas. We use satellite retrievals nitrogen dioxide (NO2) formaldehyde (HCHO, an indicator VOC) Tropospheric Monitoring Instrument (TROPOMI) track evolution O3 over California 2018 2020. improved these by updating a priori profiles explicitly accounting for effects smoke aerosols. TROPOMI observations reveal that extensive intense fire 2020 led overall increase statewide annual average HCHO NO2 columns 16% 9%. level offsets anthropogenic NOx emission reduction COVID-19 lockdown. enhancement within plumes is concentrated near regions actively burning, whereas far-reaching, extending areas due secondary production longer-lived VOCs such as ethene. Consequently, larger occurs NOx-limited regions, while greater VOC-limited areas, both contributing more efficient production.

Language: Английский

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Emissions and Atmospheric Chemistry of Furanoids from Biomass Burning: Insights from Laboratory to Atmospheric Observations

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: 8(5), P. 857 - 899

Published: April 8, 2024

Furanoids are a class of reactive volatile organic compounds that major products from the pyrolysis and combustion biomass polymers, including cellulose, hemicellulose, lignin. Biomass burning is an atmospheric source furanoids increasing in frequency intensity throughout regions world. Once emitted to atmosphere, may react with oxidants form secondary pollutants hazardous human health, ozone (O3) aerosol (SOA). This review comprehensive assessment literature between 1977 present describing emissions fate wild, prescribed, domestic fires. The organized by presenting physical properties key first, followed summary biopolymer reactions lead furanoid formation. Next, factors compiled across typical fuels consumed highlight species smoke. We next available kinetic degradation mechanism data characterize reaction rates, gas-phase products, SOA formed as result OH, NO3, O3, Cl radicals. then describe studies have focused on evaluating chemistry their impacts air quality using combination field observations model simulations. conclude perspective identifies future research directions would address gaps improve understanding processes.

Language: Английский

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Impacts on Urban VOCs and PM2.5 during a Wildfire Episode

Environments, Journal Year: 2024, Volume and Issue: 11(4), P. 63 - 63

Published: March 24, 2024

This study focuses on the impact of wildfire smoke emissions regional, urban air quality during a event. We measured volatile organic compounds (VOCs) and fine particulate matter (PM2.5) in San Francisco Bay Area to assess event compared them those later non-wildfire period. VOCs were collected using thermal desorption tubes quantified desorption-gas chromatography/mass spectrometry (TD-GC/MS). Elevated concentrations such as 1,3,5-trimethylbenzene (0.33 ± 0.01 µg/m3), benzene (1.03 0.02 toluene (2.15 0.04 ethylbenzene (0.60 m, p-xylene (0.77 0.07 µg/m3) observed Compared with that season, concentration period was more than three times concentration. Similarly, almost four higher, p, m-xylene higher. The higher levels statistically significant for sec-butylbenzene, 1,2,4-trimethylbenzene, n-propylbenzene, o-xylene, styrene, 1,3,5-trimethylbenzene, benzene, toluene, ethylbenzene, p,m-xylene (p < 0.00001). These VOC non-fire may potentially pose public health concern. Open face passive sampler (OFPS)-collected PM analyzed scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) revealed carbon tar balls. highest daily average beta-attenuation-monitored PM2.5 fire 200 µg/m3 hourly 270 µg/m3. Monitoring gas phase species addition is useful season inform guidance.

Language: Английский

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Contribution of Carbonyl Chromophores in Secondary Brown Carbon from Nighttime Oxidation of Unsaturated Heterocyclic Volatile Organic Compounds

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(48), P. 20085 - 20096

Published: Nov. 20, 2023

The light absorption properties of brown carbon (BrC), which are linked to molecular chromophores, may play a significant role in the Earth's energy budget. While nitroaromatic compounds have been identified as strong chromophores wildfire-driven BrC, other types remain be investigated. Given electron-withdrawing nature carbonyls ubiquitous atmosphere, we characterized carbonyl BrC samples from nighttime oxidation furan and pyrrole derivatives, important but understudied precursors secondary organic aerosols primarily found wildfire emissions. Various were quantified samples, their ultraviolet-visible spectra simulated by using time-dependent density functional theory. Our findings suggest that with bonded nitrogen (i.e., imides amides) derived N-containing heterocyclic substantially contribute absorption. contributed over 40% total at wavelengths below 350 nm above 430 BrC. contributions differed significantly wavelength, highlighting divergent importance different wavelength ranges. Overall, our highlight significance underscore need for further investigation.

Language: Английский

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Emissions of organic compounds from western US wildfires and their near-fire transformations

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(15), P. 9877 - 9893

Published: Aug. 3, 2022

Abstract. The size and frequency of wildfires in the western United States have been increasing, this trend is projected to continue, with increasing adverse consequences for human health. Gas- particle-phase organic compounds are main components wildfire emissions. Some directly emitted hazardous air pollutants, while others can react oxidants form secondary pollutants such as ozone aerosol (SOA). Further, particle phase volatize during smoke transport then serve precursors SOA. extent pollutant formation from emissions dependent part on speciation compounds. most detailed has achieved laboratory studies, though recent field campaigns leading an increase measurements field. In study, we identified quantified hundreds gas- conifer-dominated US, using two two-dimensional gas chromatography coupled time-of-flight mass spectrometry (GC × GC ToF-MS) instruments. Observed emission factors (EFs) ratios reported four wildfires. As demonstrated previously, modified combustion efficiency (MCE) was a good predictor EFs (e.g., R2=0.78 0.84 sugars terpenoids, respectively), except elemental carbon. Higher diterpenoids, resin acids, monoterpenes were observed relative likely due distillation unburned heated vegetation, which may be underrepresented studies. These diterpenoids acids accounted up 45 % total aerosol, higher than contribution sugar derivatives. low volatility makes them ideal markers conifer fire smoke. speciated also show that evaporation semi-volatile took place plumes, suggests evaporated primary precursor SOAs plumes.

Language: Английский

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Synergistic Enhancement of Hydrophobic n-Hexane Biodegradation in a Biotrickling Filter: Role of Hydrophilic VOCs in Mass Transfer and Extracellular Polymeric Secretion

Environmental Pollution, Journal Year: 2025, Volume and Issue: unknown, P. 126297 - 126297

Published: April 1, 2025

Language: Английский

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Rate Coefficients for the Gas-Phase Reactions of Nitrate Radicals with a Series of Furan Compounds

The Journal of Physical Chemistry A, Journal Year: 2022, Volume and Issue: 126(46), P. 8674 - 8681

Published: Nov. 9, 2022

The atmospheric reaction of a series furan compounds (furan (F), 2-methylfuran (2-MF), 3-methylfuran (3-MF), 2,5-dimethylfuran (2,5-DMF), and 2,3,5-trimethylfuran (2,3,5-TMF)) with nitrate radical (NO3) has been investigated using the relative rate kinetic method in CHamber for Atmospheric Reactivity Metrology Environment (CHARME) simulation chamber at laboratoire de Physico-Chimie l'Atmosphere (LPCA) laboratory (Dunkerque, France). experiments were performed (294 ± 2) K pressure under dry conditions (relative humidity, RH < 2%) proton transfer mass reaction–time flight–mass spectrometer (PTR-ToF-MS) chemical analysis. following coefficients (in units cm3 molecule–1 s–1) determined: furan, k(F) = (1.51 0.38) × 10–12, 2-methylfuran, k(2-MF) (1.91 0.32) 10–11, 3-methylfuran, k(3-MF) (1.49 0.33) 2,5-dimethylfuran, k(2,5-DMF) (5.82 1.21) 2,3,5-trimethylfuran, k(2,3,5-TMF) (1.66 0.69) 10–10. uncertainty on measured coefficient (ΔkFC) includes both measurement that reference molecule. To our knowledge, this work represents first determination 2,3,5-TMF NO3. This shows between methylated is dominant removal pathway during night lifetimes 0.5 55 min studied molecules.

Language: Английский

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Photolytic Mass Loss of Secondary Organic Aerosol Derived from Photooxidation of Biomass Burning Furan Precursors

ACS ES&T Air, Journal Year: 2025, Volume and Issue: 2(4), P. 476 - 485

Published: March 11, 2025

Direct photolysis as a potentially important chemical loss pathway for atmospheric organic aerosol (OA) is increasingly recognized but remains highly uncertain, particularly secondary (SOA) derived from biomass burning (BB) precursors. We present the measurements of photolytic mass change SOA photooxidation three furan precursors, 3-methylfuran, 2-methylfuran, and furfural, in an environmental chamber under both dry humid conditions. Each type was collected on crystal sensors, losses by 300 or 340 nm light were continuously monitored using quartz microbalance (QCM). By incorporation modeling, 10-40% masses can be lost direct solar radiation over their typical lifetime. The fraction well correlated with nitrogen-containing compounds (NOC) SOA, possibly because these species largely enhance absorption cross section readily undergo photodissociation UV light.

Language: Английский

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Measurement report: Observations of long-lived volatile organic compounds from the 2019–2020 Australian wildfires during the COALA campaign

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(17), P. 11033 - 11047

Published: Aug. 31, 2022

Abstract. In 2019–2020, Australia experienced its largest wildfire season on record. Smoke covered hundreds of square kilometers across the southeastern coast and reached site COALA-2020 (Characterizing Organics Aerosol Loading over Australia) field campaign in New South Wales. Using a subset nighttime observations made by proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), we calculate emission ratios (ERs) factors (EFs) for 15 volatile organic compounds (VOCs). We restrict our analysis to VOCs with sufficiently long lifetimes be minimally impacted oxidation ∼ 8 h between when smoke was emitted it arrived at site. use oxidized VOC assess total amount radical oxidation: maleic anhydride / furan OH oxidation, (cis-2-butenediol + furanone) NO3 oxidation. examine time series O3 NO2 given their closely linked chemistry plumes observe trends during event. Then compare ERs calculated from freshest portion plume using entire period. Finding good agreement two, are able extend measured more chemically aged portions plume. Our provides EFs six not previously reported temperate forests Australia: acrolein (a compound significant health impacts), methyl propanoate, methacrylate, anhydride, benzaldehyde, creosol. results two studies similar Australian biomes, focused US forests. find half within factor 2.5 relative those presented biome studies, nearly all 5, indicating reasonable agreement. For US-focused 2.5, again reasonably This suggests that comprehensive measurements biomass burning emissions other regions may applicable Finally, quantify magnitude attributable primary contributing reactivity this plume, finding comparable several US-based laboratory studies.

Language: Английский

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Gas–particle partitioning of semivolatile organic compounds when wildfire smoke comes to town

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(19), P. 12441 - 12454

Published: Oct. 6, 2023

Abstract. Wildfires have become an increasingly important source of organic gases and particulate matter in the western USA. A large fraction emitted wildfires is semivolatile, oxidation smoke can form lower-volatility products that then condense on particulates. In this research, we measured gas- particle-phase concentrations semivolatile compounds (SVOCs) during 2017 northern California a downwind urban area, using thermal desorption aerosol gas chromatography (SV-TAG), SVOCs rural site affected by biomass burning cTAG (comprehensive mass spectrometry) Idaho 2018. Commonly used markers such as levoglucosan, mannosan, nitrocatechols were found to stay predominantly particle phase, even when ambient (OA) was relatively low. The phase partitioning observed be dependent their saturation vapor pressure, while equilibrium absorption model underpredicts most measured. Wildfire enhanced condensation polar into but not some nonpolar compounds, polycyclic aromatic hydrocarbons.

Language: Английский

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