Molecular Properties of Brown Carbon Aerosol from Biomass Burning of Wildland Fuels at the Fire Sciences Laboratory

ACS ES&T Air, Journal Year: 2025, Volume and Issue: unknown

Published: April 16, 2025

Language: Английский

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Measurements of brown carbon and its optical properties from boreal forest fires in Alaska summer

Atmospheric Environment, Journal Year: 2024, Volume and Issue: 324, P. 120436 - 120436

Published: Feb. 29, 2024

Language: Английский

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Characterization of Brown Carbon absorption in different European environments through source contribution analysis

Published: July 26, 2024

Abstract. Brown carbon (BrC) is a fraction of Organic Aerosols (OA) that absorbs radiation in the ultraviolet and short visible wavelengths. Its contribution to radiative forcing uncertain due limited knowledge its imaginary refractive index (k ). This study investigates variability k for OA from wildfires, residential, shipping, traffic emission sources over Europe. The MONARCH atmospheric chemistry model simulated concentrations source contributions, feeding an offline optical tool constrain values at 370 nm. was evaluated against mass Aerosol Chemical Speciation Monitors (ACSM) filter sample measurements, aerosol light absorption measurements nm derived AethalometerTM 12 sites across Results show captures temporal environments (regional, suburban urban background). Residential emissions are major colder months, while secondary organic aerosols (SOA) dominate warmer periods. Traffic minor primary contributor. Biomass coal combustion significantly influence absorption, with shipping also notable near harbors. Optimizing revealed significant influenced by environmental conditions. Derived biomass burning (0.03 0.13), residential (0.008 (0.005 0.08), 0.07) improved representation compared constant k. Introducing such source-specific constraints innovative approach enhance models.

Language: Английский

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Aircraft Measurements from a U.S. Western Wildfire Demonstrating Day and Night Differences in the Chemical Composition and Optical Properties of Biomass Burning Aerosols and Their Atmospheric Evolution

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 23, 2024

The composition and transformations of biomass burning aerosols (BBA) have been measured onboard the NOAA Twin Otter research aircraft during Fire Influence on Regional to Global Environments Air Quality field study. We analyze real-time aerosol mass spectrometry measurements across three flights afternoon, late night August 28, 2019, for one midsized wildfire. Analysis several metrics showed that optical properties varied depending conditions at fire zone time day BBA was emitted, with substantial variations in available sunlight. total loadings were dominated by organic components a much smaller contribution from inorganic species. A gradual buildup material observed afternoon as plume aged, indicating condensation photochemically formed low-volatility oxidized compounds. Highly hygroscopic ammonium nitrate main component, suggesting potential water content particles likelihood their aqueous-phase reactivity. Depletions particle-phase NO3– Cl– relative carbon monoxide nighttime plumes, respectively, aligning known gas-particle partitioning thermodynamics heterogeneous chemistry dissolved chloride. wavelength-dependent light absorption species higher sampled no significant changes age, despite trends downwind. These differences particle demonstrate processes involved aging are not uniform same wildfire over course depend highly when well phase emissions source.

Language: Английский

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Cost-effective off-grid automatic precipitation samplers for pollutant and biogeochemical atmospheric deposition

Atmospheric measurement techniques, Journal Year: 2024, Volume and Issue: 17(12), P. 3697 - 3718

Published: June 20, 2024

Abstract. An important transport process for particles and gases from the atmosphere to aquatic terrestrial environments is through dry wet deposition. open-source, modular, off-grid, affordable instrument that can automatically collect wet-deposition samples allows more extensive deployment of deposition samplers in fieldwork would enable comprehensive monitoring remote locations. Precipitation events selectively sampled using a conductivity sensor powered by battery-based supply are central off-grid capabilities. The prevalence conductive precipitation – which initially contains high solute levels progresses trace-level concentrations ultrapure water full atmospheric washout depends on sampling location but ubiquitous. This property exploited here trigger an electric motor (via limit switches) open close lid resting over funnel opening. motors operated via custom-built modular digital logic control board, has low energy demand. All components, their design rationale, assembly provided community use. modularity board operation up six independent units, such replicate measurements (e.g., canopy throughfall) or different collection materials various targeted pollutants be implemented as necessary. We demonstrate these platforms capable continuous integrated monthly bimonthly collections performed across Newfoundland Labrador Boreal Ecosystem Latitudinal Transect (47 53° N) during growing seasons 2015 2016. System performance was assessed measured power consumption 115 V alternating current (VAC; grid power) 12 direct battery supplies under both standby (40 230 mA, respectively) in-use (78 300 conditions. In field, one set triplicate deployed incident (open fall), while another experimental forest (throughfall). proof-of-concept systems were validated with basic rainwater chemistry, found (i) pH values ranging 4.14 5.71 fall rainwater, (ii) conductivities 21 166 µS cm−1, (iii) dissolved organic carbon throughfall 16±10 22±12 mg L−1, respectively, fluxes spanning 600 4200 C m−2 a−1 transect. Ultimately, this demonstrates customized new platform enables universal accessibility observation example, those who have made calls targeting biogeochemical budgets and/or contaminants emerging concern sensitive regions.

Language: Английский

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Brown Carbon Emissions from Biomass Burning under Simulated Wildfire and Prescribed-Fire Conditions

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(9), P. 1124 - 1136

Published: Aug. 21, 2024

We investigated the light-absorption properties of brown carbon (BrC) as part Georgia Wildland-Fire Simulation Experiment. constructed fuel beds representative three ecoregions in Southeastern U.S. and varied fuel-bed moisture content to simulate either prescribed fires or drought-induced wildfires. Based on decreasing fire radiative energy normalized by mass loading (FRE

Language: Английский

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Characterization of water-soluble brown carbon chromophores from wildfire plumes in the western USA using size-exclusion chromatography

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(24), P. 15643 - 15654

Published: Dec. 20, 2023

Abstract. Wildfires are an important source of carbonaceous aerosol in the atmosphere. Organic that absorbs light ultraviolet to visible spectral range is referred as brown carbon (BrC), and its impact on Earth's radiative budget has not been well characterized. We collected water-soluble using a particle-into-liquid sampler (PILS) board Twin Otter aircraft during Fire Influence Regional Global Environments Air Quality (FIREX-AQ) campaign. Samples were downwind wildfires western United States from August September 2019. applied size-exclusion chromatography (SEC) with ultraviolet-visible spectroscopy characterize molecular size distribution BrC chromophores. The wildfire plumes had transport ages 0 5 h, absorption was dominated by chromophores weights <500 Da. With normalized conserved biomass burning tracer, monoxide, consistent decrease plume age observed FIREX-AQ. These findings variable trends reported recent studies. While broadly between offline SEC analysis online PILS measurements, absolute values their dependence differed. investigate plausible explanations for discrepancies analyses. This included solvent effects, pH, sample storage. suspect storage impacted intensity measurements without impacting weight

Language: Английский

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Beyond the Ångström Exponent: Probing Additional Information in Spectral Curvature and Variability of In Situ Aerosol Hyperspectral (0.3–0.7 μm) Optical Properties

Journal of Geophysical Research Atmospheres, Journal Year: 2022, Volume and Issue: 127(21)

Published: Oct. 26, 2022

Abstract Ångström exponents ( α ) allow reconstruction of aerosol optical spectra over a broad range wavelengths from measurements at two or more wavelengths. Hyperspectral atmospheric aerosols provide opportunities to probe measured for information inaccessible only few Four sets hyperspectral in situ coefficients (aerosol‐phase total extinction, σ ext , and absorption, abs ; liquid‐phase soluble absorption methanol, MeOH‐abs water, DI‐abs extracts) were biomass burning (BBAs). single scattering albedo ω ), calculated spectral resolution wide rare this parameter. Observed shifts between / argue favor measuring rather than reconstructing it liquid extracts. Logarithmically transformed exhibited curvature better fit by second‐order polynomials linear . Mapping second order 1 2 revealed samples given fire tended cluster together, that is, similar each other somewhat distinct others. Separation space with the same suggest additional parameterization absent fit. Spectral features found residuals indicate captured fits. Above‐detection 0.7 μm suggests assuming all long visible is BC partition brown carbon (BrC) overestimates underestimates BrC across range. may eventually discriminate BBA among fires different ecosystems under variable conditions.

Language: Английский

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Modeling atmospheric brown carbon in the GISS ModelE Earth system model

Published: Nov. 14, 2023

Abstract. Brown carbon (BrC) is an absorbing organic aerosol, primarily emitted through biomass burning, that exhibits light absorption unique from both black (BC) and other aerosols (OA). Despite many field laboratory studies seeking to constrain BrC properties, the radiative forcing of still highly uncertain. To better understand it’s climate impact, we introduced One-Moment Aerosol (OMA) module GISS ModelE Earth system model (ESM). We assessed sensitivity primary processed a novel chemical aging scheme, as well secondary formed biogenic volatile compounds (BVOCs). Initial results show typically contributes top atmosphere (TOA) effect 0.04 W m-2. Sensitivity tests indicate explicitly simulating (separating it OA), including BrC, bleaching all contribute distinguishable effects should be accounted for in schemes. This addition prognostic allows greater physical complexity OA representation with no apparent trade-off performance evaluation aerosol optical depth, without against AERONET MODIS retrieval data reveals similar skill cases. Thus, simulated allow more physically based composition, which crucial detailed study like comparisons in-situ measurement campaigns. include additional recommendations within ESMs at end this paper.

Language: Английский

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Comment on egusphere-2023-2472

Published: Feb. 14, 2024

Abstract. Brown carbon (BrC) is an absorbing organic aerosol, primarily emitted through biomass burning, that exhibits light absorption unique from both black (BC) and other aerosols (OA). Despite many field laboratory studies seeking to constrain BrC properties, the radiative forcing of still highly uncertain. To better understand it’s climate impact, we introduced One-Moment Aerosol (OMA) module GISS ModelE Earth system model (ESM). We assessed sensitivity primary processed a novel chemical aging scheme, as well secondary formed biogenic volatile compounds (BVOCs). Initial results show typically contributes top atmosphere (TOA) effect 0.04 W m^-2. Sensitivity tests indicate explicitly simulating (separating it OA), including BrC, bleaching all contribute distinguishable effects should be accounted for in schemes. This addition prognostic allows greater physical complexity OA representation with no apparent trade-off performance evaluation aerosol optical depth, without against AERONET MODIS retrieval data reveals similar skill cases. Thus, simulated allow more physically based composition, which crucial detailed study like comparisons in-situ measurement campaigns. include additional recommendations within ESMs at end this paper.

Language: Английский

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