Biomass-burning-derived particles from a wide variety of fuels – Part 1: Properties of primary particles

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(3), P. 1531 - 1547

Published: Feb. 7, 2020

Abstract. Relationships between various optical, physical, and chemical properties of biomass-combustion-derived particles are characterized for produced in the laboratory from a wide range fuels burn conditions. The modified combustion efficiency (MCE), commonly used to parameterize biomass particle emissions properties, is shown generally have weak predictive capabilities, especially more efficient There is, however, strong relationship many intensive optical (e.g., single-scatter albedo, Ångström absorption exponent, mass efficiency) organic aerosol-to-black carbon ([OA] ∕ [BC]) ratio over wider than previously considered (0.3 105). brown (BrC, i.e., light-absorbing carbon) also vary with [OA] [BC]. Coating-induced enhancements (i.e., “lensing” effects) contribute only minor amount BC all burns despite some producing having large ensemble-average coating-to-core ratios. BC–OA mixing state varies strongly [BC]; fraction OA that internally mixed decreases [BC] while relative coated on increases. In contrast, there little bulk [BC], O : C H atomic ratios abundance key marker ion (m/z=60, linked levoglucosan) showing no dependence both nitrate volatility do depend Neither total nor BC-specific size distributions exhibit any clear conditions or although perhaps fuel type. Overall, our results expand existing knowledge new understanding emitted combustion.

Language: Английский

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Rapid evolution of aerosol particles and their optical properties downwind of wildfires in the western US

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(21), P. 13319 - 13341

Published: Nov. 11, 2020

Abstract. During the first phase of Biomass Burn Operational Project (BBOP) field campaign, conducted in Pacific Northwest, DOE G-1 aircraft was used to follow time evolution wildfire smoke from near point emission locations 2–3.5 h downwind. In nine flights we made repeated transects plumes at varying downwind distances and could thereby plume's evolution. On average there little change dilution-normalized aerosol mass concentration as a function distance. This consistency hides dynamic system which primary particles are evaporating secondary ones condensing. Organic is oxidized result. all more than 90 % organic. freshly emitted aerosol, NH4+ approximately equivalent NO3. After 2 daytime aging, increased sum Cl, SO42, Particle size with distance, causing be efficient scatters. Averaged over flights, scattering efficiency (MSE) ∼ by 56 doubled one flight. Mechanisms for redistributing small large discussed. Coagulation effective moving Aitken accumulation modes but yields only minor increase MSE. As absorption remained nearly constant age, single scatter albedo controlled age-dependent scattering. Near-fire had (SSA) 0.8–0.9. 1 aging SSAs were typically 0.9 greater. Assuming global-average surface atmospheric conditions, observed age dependence SSA would direct radiative effect plume zero fire cooling

Language: Английский

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Biomass-burning-derived particles from a wide variety of fuels – Part 2: Effects of photochemical aging on particle optical and chemical properties

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(14), P. 8511 - 8532

Published: July 22, 2020

Abstract. Particles in smoke emitted from biomass combustion have a large impact on global climate and urban air quality. There is limited understanding of how particle optical properties – especially the contributions black carbon (BC) brown (BrC) evolve with photochemical aging smoke. We analyze evolution chemical composition particles produced wide variety fuels, largely western United States. The photochemically aged reaction chamber over atmospheric-equivalent timescales ranging 0.25 to 8 d. Various aerosol (e.g., single-scatter albedo, wavelength dependence absorption, BC mass absorption coefficient, MACBC) evolved aging, specific dependent initial conditions. coatings (the so-called lensing effect) was small, even after aging. BrC absorptivity (MACBrC) varied between individual burns but decreased consistently at longer times; generally increased observed changes result combination secondary organic (SOA) production heterogeneous oxidation primary OA mass, SOA being major driver changes. time, reflecting both formation precursors having range lifetimes respect OH evolving environment within chamber. Although decreases dilution-corrected may actually increase SOA. These experimental results provide context for interpretation ambient observations biomass-combustion-derived plumes.

Language: Английский

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Atmospheric aging enhances the ice nucleation ability of biomass-burning aerosol

Science Advances, Journal Year: 2021, Volume and Issue: 7(9)

Published: Feb. 24, 2021

Ability of biomass-burning smoke particles to glaciate clouds increases as the plume undergoes atmospheric dilution and aging.

Language: Английский

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Estimating the air quality and health impacts of biomass burning in northern South America using a chemical transport model

The Science of The Total Environment, Journal Year: 2020, Volume and Issue: 739, P. 139755 - 139755

Published: June 5, 2020

Language: Английский

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Secondary Organic Aerosol from Typical Chinese Domestic Cooking Emissions

Environmental Science & Technology Letters, Journal Year: 2020, Volume and Issue: 8(1), P. 24 - 31

Published: Nov. 11, 2020

Cooking has been proven to be a significant source of primary organic aerosol, especially in megacities. However, the formation secondary aerosol (SOA) derived from cooking emissions is still poorly understood. In this work, four prevalent Chinese domestic types involving complicated cuisines and various methods were chosen conduct lab simulation for SOA using Gothenburg potential mass reactor (Go: PAM). After samples had aged under OH exposures 4.3–27.1 × 1010 molecules cm–3 s, was characterized by growth potentialities (1.81–3.16), elemental ratios (O/C = 0.29–0.41), spectra. Compared with other (OA), kind less oxidized oxygenated OA (LO-OOA) unique oxidation pathway (alcohol/peroxide pathway) spectra (characteristic peaks at m/z 28, 29, 41, 43, 44, 55, 57). This study expected identify actual conditions, which could contribute formulation pollution control as well health risk assessment exposure fumes.

Language: Английский

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Aerosol Mass and Optical Properties, Smoke Influence on O₃, and High NO₃ Production Rates in a Western U.S. City Impacted by Wildfires

Journal of Geophysical Research Atmospheres, Journal Year: 2020, Volume and Issue: 125(16)

Published: July 11, 2020

Abstract Evaluating our understanding of smoke from wild and prescribed fires can benefit downwind measurements that include inert tracers to test production transport reactive species chemical mechanisms. We characterized in coniferous forest fuels for >1,000 hr over two summers (2017 2018) at Missoula, Montana, surface station found a narrow range key properties. ΔPM 2.5 /ΔCO was 0.1070 ± 0.0278 (g/g) or about half the age‐independent ratios obtained free troposphere elevations (0.2348 0.0326). The average absorption Ångström exponent across both years 1.84 0.18, values available very fresh smoke. Brown carbon (BrC) persistent (~50% 401 nm) years, despite differences age. ΔBC/ΔCO doubled 2017 2018, but 2 within 33% recent airborne measurements, suggesting low sampling bias among platforms. Switching 1.0 micron cutoff increased mass scattering coefficients, often overlooked supermicron particles impact optical properties moderately aged O 3 elevated ~6 ppb on full diurnal period when wildfire present, smoke‐associated increases were highest (~9 pbb) night, substantial upwind production. NO x mostly local origin. spurred high rates production, including presence (up 2.44 −1 ) least one nighttime BrC secondary formation event could have impacted next‐day photochemistry.

Language: 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, Journal Year: 2021, Volume and Issue: 21(4), P. 2407 - 2426

Published: Feb. 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.

Language: Английский

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Evolution of Aerosol Optical Properties from Wood Smoke in Real Atmosphere Influenced by Burning Phase and Solar Radiation

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(9), P. 5677 - 5688

Published: April 20, 2021

Emissions of light-absorbing black carbon (BC) and organic aerosol (OA) from biomass burning are presented as complex mixtures, which introduce challenges in modeling their absorbing properties. In this study, we chose typical residential wood emission used a novel designed chamber to investigate the early stage evolution plumes different phases under real ambient conditions. The detailed mixing state between BC OA was evaluated, on basis optical performed achieve closure aerosol-absorbing Intensive secondary (SOA) formation observed solar radiation. flaming conditions showed higher absorptivity than smoldering conditions, is mostly internally externally mixed with BC, respectively. For (smoldering), imaginary refractive index (kOA) initially at 0.03 ± 0.01 (0.001) 0.15 0.02 (0.05 0.02) λ = 781 405 nm, respectively, half-decay time 2-3 h light but <40% decrease dark within 5 h. production less-absorbing SOA first 1-2 possible subsequent photobleaching chromophores contributed kOA. enhanced abundance decreased coatings resulted relatively maintainable BC-containing particles during evolution.

Language: Английский

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Ambient volatile organic compounds in tropical environments: Potential sources, composition and impacts – A review

Chemosphere, Journal Year: 2021, Volume and Issue: 285, P. 131355 - 131355

Published: June 30, 2021

Language: Английский

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