Biomass-burning particle measurements: Characteristic composition and chemical processing

2004 ◽  
Vol 109 (D23) ◽  
Author(s):  
Paula K. Hudson ◽  
Daniel M. Murphy ◽  
Daniel J. Cziczo ◽  
David S. Thomson ◽  
Joost A. de Gouw ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Chemical Processing ◽  
Particle Measurements ◽  
Burning Particle

scholarly journals Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

2011 ◽  
Vol 11 (4) ◽  
pp. 11995-12037 ◽  
Author(s):  
C. J. Hennigan ◽  
M. A. Miracolo ◽  
G. J. Engelhart ◽  
A. A. May ◽  
A. A. Presto ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Organic Aerosol ◽  
Heterogeneous Reactions ◽  
Chemical Processing ◽  
Science Laboratory ◽  
Enhancement Ratio ◽  
Smog Chamber ◽  
Photo Oxidation ◽  
The Us ◽  
Mass Enhancement

Abstract. Smog chamber experiments were conducted to investigate chemical and physical transformations of organic aerosol (OA) during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service's Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III). We investigated 12 different fuels commonly burned in North American wildfires. The experiments feature atmospheric and plume aerosol and oxidant concentrations; aging times ranged from 3–4.5 h. OA production, expressed as a mass enhancement ratio (ratio of OA to primary OA (POA) mass), was highly variable. OA mass enhancement ratios ranged from 2.9 in experiments where secondary OA (SOA) production nearly tripled the POA concentration, to 0.7 in experiments where photo-oxidation resulted in a 30% loss of the OA mass. The campaign-average OA mass enhancement ratio was 1.7 ± 0.7 (mean ± 1 σ); therefore, on average, there was substantial SOA production. In every experiment, the OA was chemically transformed. Even in experiments with net loss of OA mass, the OA became increasingly oxygenated and less volatile with aging, indicating that photo-oxidation transformed the POA emissions. Levoglucosan concentrations were also substantially reduced with photo-oxidation. The transformations of POA were extensive; using levoglucosan as a tracer for POA, unreacted POA only contributed 17% of the campaign-average OA mass after 3.5 h of exposure to typical atmospheric hydroxyl radical (OH) levels. Heterogeneous reactions with OH could account for less than half of this transformation, implying that the coupled gas-particle partitioning and reaction of semi-volatile vapors is an important and potentially dominant mechanism for POA processing. Overall, the results illustrate that biomass burning emissions are subject to extensive chemical processing in the atmosphere, and the timescale for these transformations is rapid.

scholarly journals Single particle characterization of biomass burning organic aerosol (BBOA): evidence for non-uniform mixing of high molecular weight organics and potassium

2015 ◽  
Vol 15 (22) ◽  
pp. 32157-32183 ◽  
Author(s):  
A. K. Y. Lee ◽  
M. D. Willis ◽  
R. M. Healy ◽  
J. M. Wang ◽  
C.-H. Jeong ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Black Carbon ◽  
High Molecular Weight ◽  
Biomass Burning ◽  
Single Particle ◽  
Critical Role ◽  
Organic Aerosol ◽  
Mixing State ◽  
Particle Measurements ◽  
Near Ultraviolet

Abstract. Biomass burning is a major source of black carbon (BC) and primary organic aerosol globally. In particular, biomass burning organic aerosol (BBOA) is strongly associated with atmospheric brown carbon (BrC) that absorbs near ultraviolet and visible light, resulting in significant impacts on regional visibility degradation and radiative forcing. The mixing state of BBOA can play a critical role in the prediction of aerosol optical properties. In this work, single particle measurements from a soot-particle aerosol mass spectrometer coupled with a light scattering module (LS-SP-AMS) were performed to examine the mixing state of BBOA, refractory black carbon (rBC) and potassium (K+, a tracer for biomass burning aerosol) in an air mass influenced by aged biomass burning. Cluster analysis of single particle measurements identified five BBOA-related particle types. rBC accounted for 3–14 w.t. % of these particle types on average. Only one particle type exhibited a strong ion signal for K+, with mass spectra characterized by low molecular weight organic species. The remaining four particle types were classified based on the apparent molecular weight of the BBOA constituents. Two particle types were associated with low potassium content and significant amounts of high molecular weight (HMW) organic compounds. Our observations indicate non-uniform mixing of particles within a biomass burning plume in terms of molecular weight and illustrate that HMW BBOA can be a key contributor to low-volatility BrC observed in BBOA particles.

Assessing pyro-convective uplift and chemical processing of Biomass Burning plumes in the ECMWF IFS

2021 ◽  
Author(s):  
Jason Williams ◽  
Vincent Huijnen ◽  
Idir Bouarar ◽  
Sophie Belamari ◽  
Samuel Remy ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Tropospheric Ozone ◽  
Emission Sources ◽  
Chemical Processing ◽  
Air Masses ◽  
Impact Surface ◽  
The Core ◽  
Tropospheric Aerosol ◽  
Forecasting System ◽  
Monitoring Service

<p>CO is an abundant tropospheric pollutant that originates from numerous emission sources. Large CO fluxes are emitted during intense Biomass Burning (BB) events over relatively short periods of a few days, which combined with the tropospheric lifetime of a month, act as a marker for air-masses influenced by burning events. Once lifted out the boundary layer, air masses influenced by BB undergo chemical processing which can be assessed by subsequent changes in tropospheric ozone. Increases in ozone and aerosol in the Free Troposphere influence photolysis at lower levels impact surface air-quality. Therefore, capturing this feedback is a necessary step towards determining tropospheric lifetimes of greenhouse gases and pollutants, which affects the fraction of transport out of the burning regions.</p><p>Here we present results from the Integrated Forecasting System (IFS) of ECMWF, which is the core of the Copernicus Atmosphere Monitoring Service (CAMS). We perform simulations with three independent chemistry modules (modified CB05, MOZART, MOCAGE), including variable photolysis schemes and variable approaches for coupling tropospheric aerosol. We choose the simulation year of 2019 corresponding with the FIREXAQ measurement campaign which occurred over California. We subsequently assess the ability of IFS in terms of (i) the representation of the transport of air masses effected by large BB emissions, (ii) the ability towards capturing chemical processing which occurs in such plumes and (iii) using large discrepancies in the simulated tropospheric profiles to imply deficiencies in BB emission estimates.</p><p> </p>

scholarly journals Elucidating determinants of aerosol composition through particle-type-based receptor modeling

2011 ◽  
Vol 11 (15) ◽  
pp. 8133-8155 ◽  
Author(s):  
M. L. McGuire ◽  
C.-H. Jeong ◽  
J. G. Slowik ◽  
R. Y.-W. Chang ◽  
J. C. Corbin ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Biomass Burning ◽  
Temporal Variability ◽  
Receptor Modeling ◽  
Rural Site ◽  
Chemical Processing ◽  
Particle Type ◽  
Receptor Modelling ◽  
Individual Particles ◽  
Aerosol Chemical Composition

Abstract. An aerosol time-of-flight mass spectrometer (ATOFMS) was deployed at a semi-rural site in southern Ontario to characterize the size and chemical composition of individual particles. Particle-type-based receptor modelling of these data was used to investigate the determinants of aerosol chemical composition in this region. Individual particles were classified into particle-types and positive matrix factorization (PMF) was applied to their temporal trends to separate and cross-apportion particle-types to factors. The extent of chemical processing for each factor was assessed by evaluating the internal and external mixing state of the characteristic particle-types. The nine factors identified helped to elucidate the coupled interactions of these determinants. Nitrate-laden dust was found to be the dominant type of locally emitted particles measured by ATOFMS. Several factors associated with aerosol transported to the site from intermediate local-to-regional distances were identified: the Organic factor was associated with a combustion source to the north-west; the ECOC Day factor was characterized by nearby local-to-regional carbonaceous emissions transported from the south-west during the daytime; and the Fireworks factor consisted of pyrotechnic particles from the Detroit region following holiday fireworks displays. Regional aerosol from farther emissions sources was reflected through three factors: two Biomass Burning factors and a highly chemically processed Long Range Transport factor. The Biomass Burning factors were separated by PMF due to differences in chemical processing which were in part elucidated by the passage of two thunderstorm gust fronts with different air mass histories. The remaining two factors, ECOC Night and Nitrate Background, represented the night-time partitioning of nitrate to pre-existing particles of different origins. The distinct meteorological conditions observed during this month-long study in the summer of 2007 provided a unique range of temporal variability, enabling the elucidation of the determinants of aerosol chemical composition, including source emissions, chemical processing, and transport, at the Canada-US border. This paper presents the first study to elucidate the coupled influences of these determinants on temporal variability in aerosol chemical composition using single particle-type-based receptor modelling.

scholarly journals Single-particle characterization of biomass burning organic aerosol (BBOA): evidence for non-uniform mixing of high molecular weight organics and potassium

2016 ◽  
Vol 16 (9) ◽  
pp. 5561-5572 ◽  
Author(s):  
Alex K. Y. Lee ◽  
Megan D. Willis ◽  
Robert M. Healy ◽  
Jon M. Wang ◽  
Cheol-Heon Jeong ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Biomass Burning ◽  
Single Particle ◽  
Radiative Forcing ◽  
Critical Role ◽  
Organic Aerosol ◽  
Mixing State ◽  
Particle Measurements ◽  
Near Ultraviolet

Abstract. Biomass burning organic aerosol (BBOA) can be emitted from natural forest fires and human activities such as agricultural burning and domestic energy generation. BBOA is strongly associated with atmospheric brown carbon (BrC) that absorbs near-ultraviolet and visible light, resulting in significant impacts on regional visibility degradation and radiative forcing. The mixing state of BBOA can play a critical role in the prediction of aerosol optical properties. In this work, single-particle measurements from a Soot-Particle Aerosol Mass Spectrometer coupled with a light scattering module (LS-SP-AMS) were performed to examine the mixing state of BBOA, refractory black carbon (rBC), and potassium (K, a tracer for biomass burning aerosol) in an air mass influenced by wildfire emissions transported from northern Québec to Toronto, representing aged biomass burning plumes. Cluster analysis of single-particle measurements identified five BBOA-related particle types. rBC accounted for 3–14 wt % of these particle types on average. Only one particle type exhibited a strong ion signal for K+, with mass spectra characterized by low molecular weight organic species. The remaining four particle types were classified based on the apparent molecular weight of the BBOA constituents. Two particle types were associated with low potassium content and significant amounts of high molecular weight (HMW) organic compounds. Our observations indicate non-uniform mixing of particles within a biomass burning plume in terms of molecular weight and illustrate that HMW BBOA can be a key contributor to low-volatility BrC observed in BBOA particles. The average mass absorption efficiency of low-volatility BBOA is about 0.8–1.1 m2 g−1 based on a theoretical closure calculation. Our estimates indicate that low-volatility BBOA contributes ∼ 33–44 % of thermo-processed particle absorption at 405 nm; and almost all of the BBOA absorption was associated with low-volatility organics.

scholarly journals Chemical and physical transformations of organic aerosol from the photo-oxidation of open biomass burning emissions in an environmental chamber

2011 ◽  
Vol 11 (15) ◽  
pp. 7669-7686 ◽  
Author(s):  
C. J. Hennigan ◽  
M. A. Miracolo ◽  
G. J. Engelhart ◽  
A. A. May ◽  
A. A. Presto ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Organic Aerosol ◽  
Heterogeneous Reactions ◽  
Chemical Processing ◽  
Science Laboratory ◽  
Enhancement Ratio ◽  
Photo Oxidation ◽  
The Us ◽  
Us Forest Service ◽  
Mass Enhancement

Abstract. Smog chamber experiments were conducted to investigate the chemical and physical transformations of organic aerosol (OA) during photo-oxidation of open biomass burning emissions. The experiments were carried out at the US Forest Service Fire Science Laboratory as part of the third Fire Lab at Missoula Experiment (FLAME III). We investigated emissions from 12 different fuels commonly burned in North American wildfires. The experiments feature atmospheric and plume aerosol and oxidant concentrations; aging times ranged from 3 to 4.5 h. OA production, expressed as a mass enhancement ratio (ratio of OA to primary OA (POA) mass), was highly variable. OA mass enhancement ratios ranged from 2.9 in experiments where secondary OA (SOA) production nearly tripled the POA concentration to 0.7 in experiments where photo-oxidation resulted in a 30 % loss of the OA mass. The campaign-average OA mass enhancement ratio was 1.7 ± 0.7 (mean ± 1σ); therefore, on average, there was substantial SOA production. In every experiment, the OA was chemically transformed. Even in experiments with net loss of OA mass, the OA became increasingly oxygenated and less volatile with aging, indicating that photo-oxidation transformed the POA emissions. Levoglucosan concentrations were also substantially reduced with photo-oxidation. The transformations of POA were extensive; using levoglucosan as a tracer for POA, unreacted POA only contributed 17 % of the campaign-average OA mass after 3.5 h of exposure to typical atmospheric hydroxyl radical (OH) levels. Heterogeneous reactions with OH could account for less than half of this transformation, implying that the coupled gas-particle partitioning and reaction of semi-volatile vapors is an important and potentially dominant mechanism for POA processing. Overall, the results illustrate that biomass burning emissions are subject to extensive chemical processing in the atmosphere, and the timescale for these transformations is rapid.

scholarly journals Rapid dark aging of biomass burning as an overlooked source of oxidized organic aerosol

2020 ◽  
Vol 117 (52) ◽  
pp. 33028-33033
Author(s):  
John K. Kodros ◽  
Dimitrios K. Papanastasiou ◽  
Marco Paglione ◽  
Mauro Masiol ◽  
Stefania Squizzato ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Urban Areas ◽  
Field Studies ◽  
Organic Aerosol ◽  
Photochemical Activity ◽  
Chemical Processing ◽  
Ambient Particulate Matter ◽  
Atmospheric Models ◽  
High Concentrations ◽  
Nitrate Aerosol

Oxidized organic aerosol (OOA) is a major component of ambient particulate matter, substantially impacting climate, human health, and ecosystems. OOA is readily produced in the presence of sunlight, and requires days of photooxidation to reach the levels observed in the atmosphere. High concentrations of OOA are thus expected in the summer; however, our current mechanistic understanding fails to explain elevated OOA during wintertime periods of low photochemical activity that coincide with periods of intense biomass burning. As a result, atmospheric models underpredict OOA concentrations by a factor of 3 to 5. Here we show that fresh emissions from biomass burning exposed to NO2 and O3 (precursors to the NO3 radical) rapidly form OOA in the laboratory over a few hours and without any sunlight. The extent of oxidation is sensitive to relative humidity. The resulting OOA chemical composition is consistent with the observed OOA in field studies in major urban areas. Additionally, this dark chemical processing leads to significant enhancements in secondary nitrate aerosol, of which 50 to 60% is estimated to be organic. Simulations that include this understanding of dark chemical processing show that over 70% of organic aerosol from biomass burning is substantially influenced by dark oxidation. This rapid and extensive dark oxidation elevates the importance of nocturnal chemistry and biomass burning as a global source of OOA.

scholarly journals Elucidating determinants of aerosol composition through particle-type-based receptor modeling

2011 ◽  
Vol 11 (3) ◽  
pp. 9831-9885 ◽  
Author(s):  
M. L. McGuire ◽  
C.-H. Jeong ◽  
J. G. Slowik ◽  
R. Y.-W. Chang ◽  
J. C. Corbin ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Biomass Burning ◽  
Temporal Variability ◽  
Receptor Modeling ◽  
Rural Site ◽  
Chemical Processing ◽  
Particle Type ◽  
Receptor Modelling ◽  
Individual Particles ◽  
Aerosol Chemical Composition

Abstract. An aerosol time-of-flight mass spectrometer (ATOFMS) was deployed at a semi-rural site in Southern Ontario to characterize the size and chemical composition of individual particles. Particle-type-based receptor modelling of these data was used to investigate the determinants of aerosol chemical composition in this region. Individual particles were classified into particle-types and positive matrix factorization (PMF) was applied to their temporal trends to separate and cross-apportion particle-types to factors. The extent of chemical processing for each factor was assessed by evaluating the internal and external mixing state of the characteristic particle-types. The nine factors identified helped to elucidate the coupled interactions of these determinants. Nitrate-laden dust was found to be the dominant type of locally emitted particles measured by ATOFMS. Several factors associated with aerosol transported to the site from intermediate local-to-regional distances were identified: the Organic factor was associated with a combustion source to the north-west; the ECOC Day factor was characterized by nearby local-to-regional carbonaceous emissions transported from the south-west during the daytime; and the Fireworks factor consisted of pyrotechnic particles from the Detroit region following holiday fireworks displays. Regional aerosol from farther emissions sources were reflected through three factors: two biomass burning factors and a highly chemically processed long range transport factor. The biomass burning factors were separated by PMF due to differences in chemical processing which were caused in part by the passage of two thunderstorm gust fronts with different air mass histories. The remaining two factors, ECOC Night and Nitrate Background, represented the night-time partitioning of nitrate to pre-existing particles of different origins. The distinct meteorological conditions observed during this month-long study in the summer of 2007 provided a unique range of temporal variability, enabling the elucidation of the determinants of aerosol chemical composition, including source emissions, chemical processing, and transport, at the Canada-US border. This paper presents the first study to characterize the coupled influences of these determinants on temporal variability in aerosol chemical composition using single particle-type-based receptor modelling.

Human-hair analysis

1992 ◽  
Vol 50 (1) ◽  
pp. 886-887
Author(s):  
Brenda E. Lambert ◽  
Ernest C. Hammond
Keyword(s):  
Human Hair ◽  
Hair Analysis ◽  
Hair Shaft ◽  
White Female ◽  
Chemical Processing ◽  
X Ray ◽  
Hair Samples ◽  
Wave Technique ◽  
Permanent Wave ◽  
Scanning Electron

The purpose of this study was to examine the external structure of four human hair shaft samples with the scanning Electron Microscope (SEM) and to obtain information regarding the chemical composition of hair by using the attached x ray microanalysis unit.The hair samples were obtained from two female subjects. Sample A was taken from a black female and had not undergone any type of chemical processing. Sample B, C, D were taken from a white female, and were natural, processed, and unpigmented, i.e. “gray”, respectively. Sample C had been bleached, tinted, and chemically altered using a permanent wave technique.

Sign in / Sign up

Export Citation Format

Share Document