Quantification of organic aerosol and brown carbon evolution in fresh wildfire plumes

Proceedings of the National Academy of Sciences, Год журнала: 2020, Номер 117(47), С. 29469 - 29477

Опубликована: Ноя. 4, 2020

Significance Wildfire emissions in the western United States have had increasingly larger impacts on air quality, health, and climate forcing recent decades. However, our understanding of how wildfire plume composition evolves remains incomplete. Particularly, evolution carbonaceous material, including fine particle mass (PM 2.5 ) light-absorbing brown carbon, has remained elusive because limited knowledge about interplay between primary subsequent chemical physical transformations that convert material vapors particles. Using a comprehensive analysis situ smoke measurements combination with simulation chamber experiments, we quantitatively assess versus secondary organic particulate matter carbon light absorption authentic wildfires plumes. These results improve fundamental evolution.

Язык: Английский

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Ozone chemistry in western U.S. wildfire plumes

Science Advances, Год журнала: 2021, Номер 7(50)

Опубликована: Дек. 8, 2021

Wildfires are a substantial but poorly quantified source of tropospheric ozone (O3). Here, to investigate the highly variable O3 chemistry in wildfire plumes, we exploit situ chemical characterization western wildfires during FIREX-AQ flight campaign and show that production can be predicted as function experimentally constrained OH exposure, volatile organic compound (VOC) reactivity, fate peroxy radicals. The exhibits rapid transition regimes. Within few daylight hours, formation substantially slows is largely limited by abundance nitrogen oxides (NOx). This finding supports previous observations enhanced when VOC-rich smoke mixes into NOx-rich urban thereby deteriorating air quality. Last, relate underlying fire characteristics, enabling more accurate representation atmospheric models used study quality predict climate.

Язык: Английский

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Fire Influence on Regional to Global Environments and Air Quality (FIREX‐AQ)

Journal of Geophysical Research Atmospheres, Год журнала: 2022, Номер 128(2)

Опубликована: Дек. 30, 2022

Abstract The NOAA/NASA Fire Influence on Regional to Global Environments and Air Quality (FIREX‐AQ) experiment was a multi‐agency, inter‐disciplinary research effort to: (a) obtain detailed measurements of trace gas aerosol emissions from wildfires prescribed fires using aircraft, satellites ground‐based instruments, (b) make extensive suborbital remote sensing fire dynamics, (c) assess local, regional, global modeling fires, (d) strengthen connections observables the ground such as fuels fuel consumption satellite products burned area radiative power. From Boise, ID western were studied with NASA DC‐8 two NOAA Twin Otter aircraft. high‐altitude ER‐2 deployed Palmdale, CA observe some these in conjunction overpasses other Further conducted three mobile laboratories sites, 17 different forecast analyses for fire, air quality climate implications. Salina, KS investigated 87 smaller Southeast in‐situ data collection. Sampling by all platforms designed measure gases aerosols multiple transects capture chemical transformation perform observations smoke plumes under day night conditions. linked consumed power orbital collected during overflights sampling fuels.

Язык: Английский

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Formation of secondary organic aerosol from wildfire emissions enhanced by long-time ageing

Nature Geoscience, Год журнала: 2024, Номер 17(2), С. 124 - 129

Опубликована: Янв. 9, 2024

Язык: Английский

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Nighttime and daytime dark oxidation chemistry in wildfire plumes: an observation and model analysis of FIREX-AQ aircraft data

Atmospheric chemistry and physics, Год журнала: 2021, Номер 21(21), С. 16293 - 16317

Опубликована: Ноя. 8, 2021

Abstract. Wildfires are increasing in size across the western US, leading to increases human smoke exposure and associated negative health impacts. The impact of biomass burning (BB) smoke, including wildfires, on regional air quality depends emissions, transport, chemistry, oxidation emitted BB volatile organic compounds (BBVOCs) by hydroxyl radical (OH), nitrate (NO3), ozone (O3). During daytime, when light penetrates plumes, BBVOCs oxidized mainly O3 OH. In contrast, at night or optically dense NO3. This work focuses transition between daytime nighttime oxidation, which has significant implications for formation secondary pollutants loss nitrogen oxides (NOx=NO+NO2) been understudied. We present wildfire plume observations made during FIREX-AQ (Fire Influence Regional Global Environments Air Quality), a field campaign involving multiple aircraft, ground, satellite, mobile platforms that took place United States summer 2019 study both agricultural emissions atmospheric chemistry. use from two research NASA DC-8 NOAA Twin Otter, with detailed chemical box model, updated phenolic mechanisms, analyze sampled midday, sunset, nighttime. Aircraft suggest range NO3 production rates (0.1–1.5 ppbv h−1) plumes transported midday after dark. Modeled initial instantaneous reactivity toward NO3, OH, is 80.1 %, 87.7 99.6 respectively. Initial 10–104 times greater than typical values forested urban environments, reactions account >97 % sunlit (jNO2 up 4×10-3s-1), while conventional photochemical through reaction NO photolysis minor pathways. Alkenes furans mostly OH (11 %–43 54 %–88 alkenes; 18 %–55 39 %–76 furans, respectively), but split O3, (26 %–52 22 16 %–33 respectively). Nitrate accounts 26 sunset an thick plume. Nitrocatechol yields varied 33 45 chemistry late day responsible 72 %–92 (84 plume) nitrocatechol controls nitrophenolic overall. As result, overnight pathways 56 %±2 NOx sunrise following day. all one we modeled, there was remaining (13 %–57 %) (8 %–72 sunrise.

Язык: Английский

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The research hotspots and trends of volatile organic compound emissions from anthropogenic and natural sources: A systematic quantitative review

Environmental Research, Год журнала: 2022, Номер 216, С. 114386 - 114386

Опубликована: Сен. 24, 2022

Volatile organic compound (VOC) emissions have attracted wide attention due to their impacts on atmospheric quality and public health. However, most studies reviewed certain aspects of natural VOCs (NVOCs) or anthropogenic (AVOCs) rather than comprehensively quantifying the hotspots evolution trends AVOCs NVOCs. We combined bibliometric method with tree Markov chain identify research focus uncover in VOC emission sources. This study found that mainly focused characteristics, effects air health, under climate change. More concerned NVOCs, AVOC shifted a decreasing proportion transport an increasing share solvent utilization countries high publications (China USA). Research is imperative develop efficient economical abatement techniques specific sources BTEX species mitigate detrimental effects. NVOCs originating from human risen application medicine, while sensitive change grew slowly, including plants, biomass burning, microbes, soil oceans. long-term responses derived various warming warranted explore feedback global climate. It worthwhile establish inventory all kinds sources, accurate estimation, spatial temporal resolution capture synergy industrialization as well simulate quality. review both health point out directions for comprehensive control mitigation O3 pollution.

Язык: Английский

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Emissions of intermediate-volatility and semi-volatile organic compounds from domestic fuels used in Delhi, India

Atmospheric chemistry and physics, Год журнала: 2021, Номер 21(4), С. 2407 - 2426

Опубликована: Фев. 18, 2021

Abstract. Biomass burning emits significant quantities of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) in a complex mixture, probably containing many thousands chemical species. These components are significantly more toxic have poorly understood chemistry compared to volatile routinely quantified ambient air; however, analysis I/SVOCs presents difficult analytical challenge. The gases particles emitted during the test combustion range domestic solid fuels collected from across Delhi were sampled analysed. Organic aerosol was onto Teflon (PTFE) filters, residual low-volatility adsorbed surface solid-phase extraction (SPE) discs. A new method relying on accelerated solvent (ASE) coupled comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC–ToF-MS) developed. This highly sensitive powerful technique enabled over 3000 peaks I/SVOC species unique spectra be detected. total 15 %–100 % gas-phase emissions 7 particle-phase characterised. analysed for suitability make quantitative measurements using SPE Analysis discs indicated phenolic furanic important levoglucosan phase. Gas- emission factors 21 polycyclic aromatic hydrocarbons (PAHs) derived, including 16 listed by US EPA as priority pollutants. Gas-phase dominated smaller PAHs. measured (mg kg−1) PAHs cow dung cake (615), municipal waste (1022), crop residue (747), sawdust (1236), fuelwood (247), charcoal (151) liquefied petroleum (56). results this study indicate that likely PAH sources, further is required quantify their impact alongside burning.

Язык: Английский

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Production of Formate via Oxidation of Glyoxal Promoted by Particulate Nitrate Photolysis

Environmental Science & Technology, Год журнала: 2021, Номер 55(9), С. 5711 - 5720

Опубликована: Апрель 16, 2021

Particulate nitrate photolysis can produce oxidants (i.e., OH, NO2, and NO2–/HNO2) in aqueous droplets may play a potential role increased atmospheric oxidative capacity. Our earlier works have reported on the SO2 oxidation promoted by to sulfate. Here, we used glyoxal as model precursor examine of particulate formation secondary organic aerosol (SOA) from particle-phase OH radicals. Particles containing sodium were irradiated at 300 nm. Interestingly, typical products oxalic acid, glyoxylic higher-molecular-weight literature not found photooxidation process during particle phase. Instead, formic acid/formate production was main product. At concentration higher than 3 M, that rate increases significantly with increasing concentration. Such results suggest high concentrations radicals produced particles contribute SOA since acid is volatile species. Furthermore, recent predictions most advanced chemical models are lower ambient observations both ground level altitude. The present study reveals new insight into well sink atmosphere, which partially narrow gap between field measurements

Язык: Английский

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Atmospheric Reactivity of Methoxyphenols: A Review

Environmental Science & Technology, Год журнала: 2022, Номер 56(5), С. 2897 - 2916

Опубликована: Фев. 21, 2022

Methoxyphenols emitted from lignin pyrolysis are widely used as potential tracers for biomass burning, especially wood burning. In the past ten years, their atmospheric reactivity has attracted increasing attention academic community. Thus, this work provides an extensive review of methoxyphenols, including gas-phase, particle-phase, and aqueous-phase reactions, well secondary organic aerosol (SOA) formation. Emphasis was placed on kinetics, mechanisms, SOA The reactions methoxyphenols with OH NO3 radicals were predominant degradation pathways, which also had significant formation potentials. reaction mechanism O3 is cycloaddition to benzene ring or unsaturated C═C bond, while H-abstraction radical adduct main channels by radicals. Based published studies, knowledge gaps pointed out. Future studies experimental simulations theoretical calculations other representative kinds should be systematically carried out under complex pollution conditions. addition, ecotoxicity products contribution aging biomass-burning plumes seriously assessed.

Язык: Английский

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Uncovering the dominant contribution of intermediate volatility compounds in secondary organic aerosol formation from biomass-burning emissions

National Science Review, Год журнала: 2024, Номер 11(3)

Опубликована: Янв. 9, 2024

ABSTRACT Organic vapors from biomass burning are a major source of secondary organic aerosols (SOAs). Previous smog chamber studies found that the SOA contributors in biomass-burning emissions mainly volatile compounds (VOCs). While intermediate volatility (IVOCs) efficient precursors and contribute considerable fraction emissions, their contribution to formation has not been directly observed. Here, by deploying newly-developed oxidation flow reactor study wood burning, we find IVOCs can ∼70% formed SOA, i.e. >2 times more than VOCs. This previously missing is interpreted be due high wall losses semi-volatile products chambers. The finding this reveals production much higher thought, highlights urgent need for research on potentially other emission sources.

Язык: Английский

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