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Articles 1 - 14 of 14
Full-Text Articles in Physical Sciences and Mathematics
Aerosol Mass And Optical Properties, Smoke Influence On O3, And High No3 Production Rates In A Western U.S. City Impacted By Wildfires, Vanessa Selimovic, Robert J. Yokelson, Gavin R. Mcmeeking, Sarah Coefield
Aerosol Mass And Optical Properties, Smoke Influence On O3, And High No3 Production Rates In A Western U.S. City Impacted By Wildfires, Vanessa Selimovic, Robert J. Yokelson, Gavin R. Mcmeeking, Sarah Coefield
Chemistry and Biochemistry Faculty Publications
Evaluating our understanding of smoke from wild and prescribed fires can benefit from downwind measurements that include inert tracers to test production and transport and reactive species to test chemical mechanisms. We characterized smoke from fires in coniferous forest fuels for >1,000 hr over two summers (2017 and 2018) at our Missoula, Montana, surface station and found a narrow range for key properties. ΔPM2.5/ΔCO was 0.1070 ± 0.0278 (g/g) or about half the age-independent ratios obtained at free troposphere elevations (0.2348 ± 0.0326). The average absorption Ångström exponent across both years was 1.84 ± 0.18, or about half the values …
Production Of Secondary Organic Aerosol During Aging Of Biomass Burning Smoke From Fresh Fuels And Its Relationship To Voc Precursors, A. T. Ahern, E. S. Robinson, D. S. Tkacik, R. Saleh, L. E. Hatch, K. C. Barsanti, C. E. Stockwell, R. J. Yokelson, A. A. Presto, A. L. Robinson, R. C. Sullivan, N. M. Donahue
Production Of Secondary Organic Aerosol During Aging Of Biomass Burning Smoke From Fresh Fuels And Its Relationship To Voc Precursors, A. T. Ahern, E. S. Robinson, D. S. Tkacik, R. Saleh, L. E. Hatch, K. C. Barsanti, C. E. Stockwell, R. J. Yokelson, A. A. Presto, A. L. Robinson, R. C. Sullivan, N. M. Donahue
Chemistry and Biochemistry Faculty Publications
After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog-chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high-resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low-volatility POA as a reference standard (akin to a naturally occurring internal standard). …
Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman
Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman
Chemistry Faculty Publications
Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their …
Emissions Of Nitrogen-Containing Organic Compounds From The Burning Of Herbaceous And Arboraceous Biomass: Fuel Composition Dependence And The Variability Of Commonly Used Nitrile Tracers, Matthew M. Coggon, Patrick R. Veres, Bin Yuan, Abigail Koss, Carsten Warneke, Jessica B. Gilman, Brian M. Lerner, Jeff Peischl, Kenneth C. Aikin, Chelsea E. Stockwell, Lindsay E. Hatch, Thomas B. Ryerson, James M. Roberts, Robert J. Yokelson, Joost A. De Gouw
Emissions Of Nitrogen-Containing Organic Compounds From The Burning Of Herbaceous And Arboraceous Biomass: Fuel Composition Dependence And The Variability Of Commonly Used Nitrile Tracers, Matthew M. Coggon, Patrick R. Veres, Bin Yuan, Abigail Koss, Carsten Warneke, Jessica B. Gilman, Brian M. Lerner, Jeff Peischl, Kenneth C. Aikin, Chelsea E. Stockwell, Lindsay E. Hatch, Thomas B. Ryerson, James M. Roberts, Robert J. Yokelson, Joost A. De Gouw
Chemistry and Biochemistry Faculty Publications
Volatile organic compounds (VOCs) emitted from residential wood and crop residue burning were measured in Colorado, U.S. When compared to the emissions from crop burning, residential wood burning exhibited markedly lower concentrations of acetonitrile, a commonly used biomass burning tracer. For both herbaceous and arboraceous fuels, the emissions of nitrogen-containing VOCs (NVOCs) strongly depend on the fuel nitrogen content; therefore, low NVOC emissions from residential wood burning result from the combustion of low-nitrogen fuel. Consequently, the emissions of compounds hazardous to human health, such as HNCO and HCN, and the formation of secondary pollutants, such as ozone generated by NOx, …
Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman
Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman
Chemistry Faculty Publications
Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air–solid interface under variable relative humidity (RH = 0–90%). The maximum reactive uptake coefficient of O3(g) by catechol γO3 = (7.49 ± 0.35) × 10–6 occurs for …
Aerosol Single Scattering Albedo Dependence On Biomass Combustion Efficiency: Laboratory And Field Studies, Shang Liu, Allison C. Aiken, Caleb Arata, Manvendra K. Dubey, C. Stockwell, Robert Yokelson, Elizabeth A. Stone, Thilina Jayarathne, Allen L. Robinson, Paul J. Demott, Sonia M. Kreidenweis
Aerosol Single Scattering Albedo Dependence On Biomass Combustion Efficiency: Laboratory And Field Studies, Shang Liu, Allison C. Aiken, Caleb Arata, Manvendra K. Dubey, C. Stockwell, Robert Yokelson, Elizabeth A. Stone, Thilina Jayarathne, Allen L. Robinson, Paul J. Demott, Sonia M. Kreidenweis
Chemistry and Biochemistry Faculty Publications
Single scattering albedo (ω) of fresh biomass burning (BB) aerosols produced from 92 controlled laboratory combustion experiments of 20 different woods and grasses was analyzed to determine the factors that control the variability in ω. Results show that ω varies strongly with fire-integrated modified combustion efficiency (MCEFI)—higher MCEFI results in lower ω values and greater spectral dependence of ω. A parameterization of ω as a function of MCEFI for fresh BB aerosols is derived from the laboratory data and is evaluated by field observations from two wildfires. The parameterization suggests that MCEFI explains 60% of …
Measurements Of Gas‐Phase Inorganic And Organic Acids From Biomass Fires By Negative‐Ion Proton‐Transfer Chemical‐Ionization Mass Spectrometry, P. Veres, James M. Roberts, I. R. Burling, C. Warneke, Joost De Gouw, Robert J. Yokelson
Measurements Of Gas‐Phase Inorganic And Organic Acids From Biomass Fires By Negative‐Ion Proton‐Transfer Chemical‐Ionization Mass Spectrometry, P. Veres, James M. Roberts, I. R. Burling, C. Warneke, Joost De Gouw, Robert J. Yokelson
Chemistry and Biochemistry Faculty Publications
[1] Emissions from 34 laboratory biomass fires were investigated at the combustion facility of the U.S. Department of Agriculture Fire Sciences Laboratory in Missoula, Montana. Gas-phase organic and inorganic acids were quantified using negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), open-path Fourier transform infrared spectroscopy (OP-FTIR), and proton-transfer-reaction mass spectrometry (PTR-MS). NI-PT-CIMS is a novel technique that measures the mass-to-charge ratio (m/z) of ions generated from reactions of acetate (CH3C(O)O−) ions with inorganic and organic acids. The emission ratios for various important reactive acids with respect to CO were determined. Emission ratios for isocyanic acid (HNCO), 1,2 …
An Analysis Of The Chemical Processes In The Smoke Plume From A Savanna Fire, Jorg Trentmann, Robert J. Yokelson, Peter V. Hobbs, Tanja Winterrath, Ted J. Christian, Meinrat O. Andreae, Sherri A. Mason
An Analysis Of The Chemical Processes In The Smoke Plume From A Savanna Fire, Jorg Trentmann, Robert J. Yokelson, Peter V. Hobbs, Tanja Winterrath, Ted J. Christian, Meinrat O. Andreae, Sherri A. Mason
Chemistry and Biochemistry Faculty Publications
[1] Photochemistry in young plumes from vegetation fires significantly transforms the initial fire emissions within the first hour after the emissions are injected into the atmosphere. Here we present an investigation of field measurements obtained in a smoke plume from a prescribed savanna fire during the SAFARI 2000 field experiment using a detailed photochemical box-dilution model. The dilution used in the model simulations was constrained by measurements of chemically passive tracers (e.g., CO) near and downwind of the fire. The emissions of the dominant carbonaceous compounds, including oxygenated ones, were taken into account. The field measurements revealed significant production of …
Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 2. First Intercomparison Of Open-Path Ftir, Ptr-Ms, And Gc-Ms/Fid/Ecd, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wein Min Hao, T. Shirai, Donald R. Blake
Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 2. First Intercomparison Of Open-Path Ftir, Ptr-Ms, And Gc-Ms/Fid/Ecd, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wein Min Hao, T. Shirai, Donald R. Blake
Chemistry and Biochemistry Faculty Publications
No abstract provided.
Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 1. Emissions From Indonesian, African, And Other Fuels, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wei Min Hao, B. H. Saharjo, Darold E. Ward
Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 1. Emissions From Indonesian, African, And Other Fuels, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wei Min Hao, B. H. Saharjo, Darold E. Ward
Chemistry and Biochemistry Faculty Publications
[1] Trace gas and particle emissions were measured from 47 laboratory fires burning 16 regionally to globally significant fuel types. Instrumentation included the following: open-path Fourier transform infrared spectroscopy; proton transfer reaction mass spectrometry; filter sampling with subsequent analysis of particles with diameter <2.5 μm for organic and elemental carbon and other elements; and canister sampling with subsequent analysis by gas chromatography (GC)/flame ionization detector, GC/electron capture detector, and GC/mass spectrometry. The emissions of 26 compounds are reported by fuel type. The results include the first detailed measurements of the emissions from Indonesian fuels. Carbon dioxide, CO, CH4, NH3, HCN, methanol, and acetic acid were the seven most abundant emissions (in order) from burning Indonesian peat. Acetol (hydroxyacetone) was a major, previously unobserved emission from burning rice straw (21–34 g/kg). The emission factors for our simulated African fires are consistent with field data for African fires for compounds measured in both …
Distributions Of Trace Gases And Aerosols During The Dry Biomass Burning Season In Southern Africa, Parikhit Sinha, Peter V. Hobbs, Robert J. Yokelson, Donald R. Blake, Song Gao, Thomas W. Kirschsetter
Distributions Of Trace Gases And Aerosols During The Dry Biomass Burning Season In Southern Africa, Parikhit Sinha, Peter V. Hobbs, Robert J. Yokelson, Donald R. Blake, Song Gao, Thomas W. Kirschsetter
Chemistry and Biochemistry Faculty Publications
[1] Vertical profiles in the lower troposphere of temperature, relative humidity, sulfur dioxide (SO2), ozone (O3), condensation nuclei (CN), and carbon monoxide (CO), and horizontal distributions of twenty gaseous and particulate species, are presented for five regions of southern Africa during the dry biomass burning season of 2000. The regions are the semiarid savannas of northeast South Africa and northern Botswana, the savanna-forest mosaic of coastal Mozambique, the humid savanna of southern Zambia, and the desert of western Namibia. The highest average concentrations of carbon dioxide (CO2), CO, methane (CH4), O3 …
Trace Gas Measurements In Nascent, Aged, And Cloud-Processed Smoke From African Savanna Fires By Airborne Fourier Transform Infrared Spectroscopy (Aftir), Robert J. Yokelson, Issac T. Bertschi, Ted J. Christian, Peter V. Hobbs, Darold E. Ward, Wei Min Hao
Trace Gas Measurements In Nascent, Aged, And Cloud-Processed Smoke From African Savanna Fires By Airborne Fourier Transform Infrared Spectroscopy (Aftir), Robert J. Yokelson, Issac T. Bertschi, Ted J. Christian, Peter V. Hobbs, Darold E. Ward, Wei Min Hao
Chemistry and Biochemistry Faculty Publications
[1] We measured stable and reactive trace gases with an airborne Fourier transform infrared spectrometer (AFTIR) on the University of Washington Convair-580 research aircraft in August/September 2000 during the SAFARI 2000 dry season campaign in Southern Africa. The measurements included vertical profiles of CO2, CO, H2O, and CH4 up to 5.5 km on six occasions above instrumented ground sites and below the TERRA satellite and ER-2 high-flying research aircraft. We also measured the trace gas emissions from 10 African savanna fires. Five of these fires featured extensive ground-based fuel characterization, and two were in the …
Trace Gas And Particle Emissions From Fires In Large Diameter And Belowground Biomass Fuels, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, R. E. Babbitt, Ronald A. Susott, Jon G. Goode, Wei Min Hao
Trace Gas And Particle Emissions From Fires In Large Diameter And Belowground Biomass Fuels, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, R. E. Babbitt, Ronald A. Susott, Jon G. Goode, Wei Min Hao
Chemistry and Biochemistry Faculty Publications
[1] We adopt a working definition of residual smoldering combustion (RSC) as biomass combustion that produces emissions that are not lofted by strong fire-induced convection. RSC emissions can be produced for up to several weeks after the passage of a flame front and they are mostly unaffected by flames. Fuels prone to RSC include downed logs, duff, and organic soils. Limited observations in the tropics and the boreal forest suggest that RSC is a globally significant source of emissions to the troposphere. This source was previously uncharacterized. We measured the first emission factors (EF) for RSC in a series of …
Trace Gas Emissions From The Production And Use Of Domestic Biofuels In Zambia Measured By Open-Path Fourier Transform Infrared Spectroscopy, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, Ted J. Christian, Wei Min Hao
Trace Gas Emissions From The Production And Use Of Domestic Biofuels In Zambia Measured By Open-Path Fourier Transform Infrared Spectroscopy, Isaac T. Bertschi, Robert J. Yokelson, Darold E. Ward, Ted J. Christian, Wei Min Hao
Chemistry and Biochemistry Faculty Publications
[1] Domestic biomass fuels (biofuels) were recently estimated to be the second largest source of carbon emissions from global biomass burning. Wood and charcoal provide approximately 90% and 10% of domestic energy in tropical Africa. In September 2000, we used open-path Fourier transform infrared (OP-FTIR) spectroscopy to quantify 18 of the most abundant trace gases emitted by wood and charcoal cooking fires and an earthen charcoal-making kiln in Zambia. These are the first in situ measurements of an extensive suite of trace gases emitted by tropical biofuel burning. We report emission ratios (ER) and emission factors (EF) for (in order …