Heterogeneous OH oxidation of biomass burning organic aerosol surrogate compounds: assessment of volatilisation products and the role of OH concentration on the reactive uptake kinetics

Abstract. Organic aerosol (OA) represents a large fraction of submicron aerosols in the megacity of Beijing, yet long-term characterization of its sources and variations is very limited. Here we present analysis of in situ measurements of OA in submicrometer particles with an aerosol chemical speciation monitor (ACSM) for two years from July 2011 to May 2013. The sources of OA are analyzed with multilinear engine (ME-2) by constraining three primary OA factors including fossil fuel related OA (FFOA), cooking OA (COA), and biomass burning OA (BBOA). Two secondary OA (SOA), representing a less oxidized oxygenated OA (LO-OOA) and a more oxidized (MO-OOA) are identified during all seasons. The monthly average concentration OA varied from 13.6 to 46.7 µg m−3 with a strong seasonal pattern that is usually highest in winter and lowest in summer. FFOA and BBOA show similarly pronounced seasonal variations with much higher concentrations and contributions in winter due to enhanced coal combustion and biomass burning emissions. The contribution of COA to OA, however, is relatively stable (10–15 %) across different seasons, yet presents significantly higher values at low relative humidity levels (RH < 30 %), highlighting the important role of COA during clean periods. The two SOA factors present very different seasonal variations. The pronounced enhancement of LO-OOA concentrations in winter indicates that emissions form combustion-related primary emissions could be a considerable source of SOA under low temperature (T) conditions. Comparatively, MO-OOA shows high concentrations consistently at high RH levels across different T levels, and the contribution of MO-OOA to OA is different seasonally with lower values occurring more in winter (30–34 %) than other seasons (47–64 %). Overall, SOA (= LO-OOA + MO-OOA) dominates OA composition during all seasons by contributing 52–64 % of the total OA mass in heating season, and 65–75 % in non-heating seasons. The variations of OA composition as a function of OA mass loading further illustrates the dominant role of SOA in OA across different mass loading scenarios during all seasons. However, we also observed a large increase in FFOA associated with a corresponding decrease in MO-OOA during periods with high OA mass loadings in heating season, illustrating an enhanced role of coal combustion emissions during highly polluted episodes. Potential source contribution function analysis further shows that the transport from the regions located to the south and southwest of Beijing within ~200 km can contribute substantially to high FFOA and BBOA concentrations in heating season.

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Source apportionment of organic aerosol from 2-year highly time-resolved measurements by an aerosol chemical speciation monitor in Beijing, China

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-8469-2018 ◽

2018 ◽

Vol 18 (12) ◽

pp. 8469-8489 ◽

Cited By ~ 40

Author(s):

Yele Sun ◽

Weiqi Xu ◽

Qi Zhang ◽

Qi Jiang ◽

Francesco Canonaco ◽

...

Keyword(s):

Biomass Burning ◽

Seasonal Variations ◽

Coal Combustion ◽

Chemical Speciation ◽

Function Analysis ◽

Dominant Role ◽

Organic Aerosol ◽

Mass Loading ◽

Heating Season

Abstract. Organic aerosol (OA) represents a large fraction of submicron aerosols in the megacity of Beijing, yet long-term characterization of its sources and variations is very limited. Here we present an analysis of in situ measurements of OA in submicrometer particles with an aerosol chemical speciation monitor (ACSM) for 2 years from July 2011 to May 2013. The sources of OA are analyzed with a multilinear engine (ME-2) by constraining three primary OA factors including fossil-fuel-related OA (FFOA), cooking OA (COA), and biomass burning OA (BBOA). Two secondary OAs (SOA), representing a less oxidized oxygenated OA (LO-OOA) and a more oxidized (MO-OOA), are identified during all seasons. The monthly average concentration OA varied from 13.6 to 46.7 µg m−3 with a strong seasonal pattern that is usually highest in winter and lowest in summer. FFOA and BBOA show similarly pronounced seasonal variations with much higher concentrations and contributions in winter due to enhanced coal combustion and biomass burning emissions. The contribution of COA to OA, however, is relatively stable (10–15 %) across different seasons, yet presents significantly higher values at low relative humidity levels (RH < 30 %), highlighting the important role of COA during clean periods. The two SOA factors present very different seasonal variations. The pronounced enhancement of LO-OOA concentrations in winter indicates that emissions from combustion-related primary emissions could be a considerable source of SOA under low-temperature (T) conditions. Comparatively, MO-OOA shows high concentrations consistently at high RH levels across different T levels, and the contribution of MO-OOA to OA is different seasonally with lower values occurring more in winter (30–34 %) than other seasons (47–64 %). Overall, SOA (= LO-OOA + MO-OOA) dominates OA composition during all seasons by contributing 52–64 % of the total OA mass in the heating season and 65–75 % in non-heating seasons. The variations in OA composition as a function of OA mass loading further illustrate the dominant role of SOA in OA across different mass loading scenarios during all seasons. However, we also observed a large increase in FFOA associated with a corresponding decrease in MO-OOA during periods with high OA mass loadings in the heating season, illustrating an enhanced role of coal combustion emissions during highly polluted episodes. Potential source contribution function analysis further shows that the transport from the regions located to the south and southwest of Beijing within ∼ 250 km can contribute substantially to high FFOA and BBOA concentrations in the heating season.

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

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2012218117 ◽

2020 ◽

Vol 117 (47) ◽

pp. 29469-29477

Author(s):

Brett B. Palm ◽

Qiaoyun Peng ◽

Carley D. Fredrickson ◽

Ben H. Lee ◽

Lauren A. Garofalo ◽

...

Keyword(s):

Biomass Burning ◽

Organic Aerosol ◽

Brown Carbon ◽

Airborne Measurements ◽

Wildfire Smoke ◽

Secondary Sources ◽

Western Us ◽

Smoke Plumes ◽

Reactive Trace Gases

The evolution of organic aerosol (OA) and brown carbon (BrC) in wildfire plumes, including the relative contributions of primary versus secondary sources, has been uncertain in part because of limited knowledge of the precursor emissions and the chemical environment of smoke plumes. We made airborne measurements of a suite of reactive trace gases, particle composition, and optical properties in fresh western US wildfire smoke in July through August 2018. We use these observations to quantify primary versus secondary sources of biomass-burning OA (BBPOA versus BBSOA) and BrC in wildfire plumes. When a daytime wildfire plume dilutes by a factor of 5 to 10, we estimate that up to one-third of the primary OA has evaporated and subsequently reacted to form BBSOA with near unit yield. The reactions of measured BBSOA precursors contribute only 13 ± 3% of the total BBSOA source, with evaporated BBPOA comprising the rest. We find that oxidation of phenolic compounds contributes the majority of BBSOA from emitted vapors. The corresponding particulate nitrophenolic compounds are estimated to explain 29 ± 15% of average BrC light absorption at 405 nm (BrC Abs405) measured in the first few hours of plume evolution, despite accounting for just 4 ± 2% of average OA mass. These measurements provide quantitative constraints on the role of dilution-driven evaporation of OA and subsequent radical-driven oxidation on the fate of biomass-burning OA and BrC in daytime wildfire plumes and point to the need to understand how processing of nighttime emissions differs.

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Secondary organic aerosol formation from biomass burning emissions

10.5194/acp-2019-326 ◽

2019 ◽

Cited By ~ 2

Author(s):

Christopher Y. Lim ◽

David H. Hagan ◽

Matthew M. Coggon ◽

Abigail R. Koss ◽

Kanako Sekimoto ◽

...

Keyword(s):

Biomass Burning ◽

Secondary Organic Aerosol ◽

Total Concentration ◽

Organic Aerosol ◽

Oh Radicals ◽

Aerosol Formation ◽

Atmospheric Aging ◽

Aerosol Mass ◽

Photochemical Aging ◽

Organic Gases

Abstract. Biomass burning is an important source of aerosol and trace gases to the atmosphere, but how these emissions change chemically during their lifetimes is not fully understood. As part of the Fire Influence on Regional and Global Environments Experiment (FIREX 2016), we investigated the effect of photochemical aging on biomass burning organic aerosol (BBOA), with a focus on fuels from the western United States. Emissions were sampled into a small (150 L) environmental chamber and photochemically aged via the addition of ozone and irradiation by 254 nm light. While some fraction of species undergoes photolysis, the vast majority of aging occurs via reaction with OH radicals, with total OH exposures corresponding to the equivalent of up to 10 days of atmospheric oxidation. For all fuels burned, large and rapid changes are seen in the ensemble chemical composition of BBOA, as measured by an aerosol mass spectrometer (AMS). Secondary organic aerosol (SOA) formation is seen for all aging experiments and continues to grow with increasing OH exposure, but the magnitude of the SOA formation is highly variable between experiments. This variability can be explained well by a combination of experiment-to-experiment differences in OH exposure and the total concentration of non-methane organic gases (NMOGs) in the chamber before oxidation, measured by PTR-ToF-MS (r2 values from 0.64 to 0.83). From this relationship, we calculate the fraction of carbon from biomass burning NMOGs that is converted to SOA as a function of equivalent atmospheric aging time, with carbon yields ranging from 24 ± 4 % after 6 hours to 56 ± 9 % after 4 days.

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Aging of atmospheric aerosols and the role of iron in catalyzing brown carbon formation

Environmental Science: Atmospheres ◽

10.1039/d1ea00038a ◽

2021 ◽

Author(s):

Hind A. A. Al-Abadleh

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Atmospheric Aerosols ◽

Secondary Organic Aerosol ◽

Organic Aerosol ◽

Atmospheric Oxidation ◽

Carbon Formation ◽

Brown Carbon ◽

Volatile Organic

Extensive research has been done on the processes that lead to the formation of secondary organic aerosol (SOA) including atmospheric oxidation of volatile organic compounds (VOCs) from biogenic and anthropogenic...

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Determining the Role of Acidity, Fate and Formation of IEPOX-Derived SOA in CMAQ

Atmosphere ◽

10.3390/atmos12060707 ◽

2021 ◽

Vol 12 (6) ◽

pp. 707

Author(s):

Petros Vasilakos ◽

Yongtao Hu ◽

Armistead Russell ◽

Athanasios Nenes

Keyword(s):

Significant Influence ◽

Organic Aerosol ◽

Liquid Water Content ◽

Anthropogenic Emissions ◽

So2 Emissions ◽

Aerosol Acidity ◽

A Value ◽

Future Emission ◽

The Impact

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability of species such as sulfate and nitrate, and through them, aerosol acidity (pH). To elucidate the role that acidity and emissions play in regulating Secondary Organic Aerosol (SOA), we utilize the 2013 Southern Oxidant and Aerosol Study (SOAS) dataset to enhance the extensive mechanism of isoprene epoxydiol (IEPOX)-mediated SOA formation implemented in the Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used to investigate the impact of potential future emission controls on IEPOX OA. We found that the Henry’s law coefficient for IEPOX was the most impactful parameter that controls aqueous isoprene OA products, and a value of 1.9 × 107 M atm−1 provides the best agreement with measurements. Non-volatile cations (NVCs) were found in higher-than-expected quantities in CMAQ and exerted a significant influence on IEPOX OA by reducing its production by as much as 30% when present. Consistent with previous literature, a strong correlation of isoprene OA with sulfate, and little correlation with acidity or liquid water content, was found. Future reductions in SO2 emissions are found to not affect this correlation and generally act to increase the sensitivity of IEPOX OA to sulfate, even in extreme cases.

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The composition and variability of atmospheric aerosol over Southeast Asia during 2008

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-1083-2012 ◽

2012 ◽

Vol 12 (2) ◽

pp. 1083-1100 ◽

Cited By ~ 11

Author(s):

W. Trivitayanurak ◽

P. I. Palmer ◽

M. P. Barkley ◽

N. H. Robinson ◽

H. Coe ◽

...

Keyword(s):

Southeast Asia ◽

Gas Phase ◽

Biomass Burning ◽

Organic Aerosol ◽

Sea Salt ◽

Dust Aerosol ◽

Small Scale ◽

Formation Mechanisms ◽

Sulphate Aerosol ◽

Phase Oxidation

Abstract. We use a nested version of the GEOS-Chem global 3-D chemistry transport model to better understand the composition and variation of aerosol over Borneo and the broader Southeast Asian region in conjunction with aircraft and satellite observations. Our focus on Southeast Asia reflects the importance of this region as a source of reactive organic gases and aerosols from natural forests, biomass burning, and food and fuel crops. We particularly focus on July 2008 when the UK BAe-146 research aircraft was deployed over northern Malaysian Borneo as part of the ACES/OP3 measurement campaign. During July 2008 we find using the model that Borneo (defined as Borneo Island and the surrounding Indonesian islands) was a net exporter of primary organic aerosol (42 kT) and black carbon aerosol (11 kT). We find only 13% of volatile organic compound oxidation products partition to secondary organic aerosol (SOA), with Borneo being a net exporter of SOA (15 kT). SOA represents approximately 19% of the total organic aerosol over the region. Sulphate is mainly from aqueous-phase oxidation (68%), with smaller contributions from gas-phase oxidation (15%) and advection into the regions (14%). We find that there is a large source of sea salt, as expected, but this largely deposits within the region; we find that dust aerosol plays only a relatively small role in the aerosol burden. In contrast to coincident surface measurements over Northern Borneo that find a pristine environment with evidence for substantial biogenic SOA formation we find that the free troposphere is influenced by biomass burning aerosol transported from the northwest of the Island and further afield. We find several transport events during July 2008 over Borneo associated with elevated aerosol concentrations, none of which coincide with the aircraft flights. We use MODIS aerosol optical depths (AOD) data and the model to put the July campaign into a longer temporal perspective. We find that Borneo is where the model has the least skill at reproducing the data, where the model has a negative bias of 76% and only captures 14% of the observed variability. This model performance reflects the small-scale island-marine environment and the mix of aerosol species, with the model showing more skill at reproducing observed AOD over larger continental regions such as China where AOD is dominated by one aerosol type. The model shows that AOD over Borneo is approximately evenly split between organic and sulphate aerosol with sea salt representing 10–20% during May–September; we find a similar breakdown over continental Southeast Asia but with less sea salt aerosol and more dust aerosol. In contrast, East China AOD is determined mainly by sulphate aerosol and a seasonal source of dust aerosol, as expected. Realistic sensitivity runs, designed to test our underlying assumptions about emissions and chemistry over Borneo, show that model AOD is most sensitive to isoprene emissions and organic gas-phase partitioning but all fail to improve significantly upon the control model calculation. This emphasises the multi-faceted dimension of the problem and the need for concurrent and coordinated development of BVOC emissions, and BVOC chemistry and organic aerosol formation mechanisms.

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Variability and sources of non-methane hydrocarbons at a Mediterranean urban atmosphere: The role of biomass burning and traffic emissions

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.149389 ◽

2021 ◽

pp. 149389

Author(s):

Anastasia Panopoulou ◽

Eleni Liakakou ◽

Stephane Sauvage ◽

Valerie Gros ◽

Nadine Locoge ◽

...

Keyword(s):

Biomass Burning ◽

Traffic Emissions ◽

Urban Atmosphere

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Night-time chemistry of biomass burning plumes in urban areas: A dual mobile chamber study

10.5194/egusphere-egu21-8469 ◽

2021 ◽

Author(s):

Spiro Jorga ◽

Kalliopi Florou ◽

Christos Kaltsonoudis ◽

John Kodros ◽

Christina Vasilakopoulou ◽

...

Keyword(s):

Biomass Burning ◽

Urban Areas ◽

Mass Spectra ◽

Prescribed Burning ◽

Organic Aerosol ◽

Photochemical Activity ◽

Organic Nitrate ◽

Night Time ◽

Starting Point ◽

High Concentrations

Biomass burning including residential heating, agricultural fires, prescribed burning, and wildfires is a major source of gaseous and particulate pollutants in the atmosphere. Although, important changes in the size distributions and the chemical composition of the biomass burning aerosol during daytime chemistry have been observed, the corresponding changes at nighttime or in winter where photochemistry is slow, have received relatively little attention. In this study, we tested the hypothesis that nightime chemistry in biomass burning plumes can be rapid in urban areas using a dual smog chamber system.&#160;Ambient urban air during winter nighttime periods with high concentrations of ambient biomass burning organic aerosol is used as the starting point. Ozone was added in the perturbed chamber to simulate mixing with background air (and subsequent NO3 production and aging) while the second chamber was used as a reference. Following the injection of ozone rapid organic aerosol (OA) formation was observed in all experiments leading to increases of the OA concentration by 20-70%. The oxygen to carbon ratio of the OA increased by 50% on average and the mass spectra of the produced OA was quite similar to that of the oxidized OA mass spectra reported during winter in urban areas. Good correlation was also observed with the produced mass spectra from nocturnal aging of laboratory biomass burning emissions showing the strong contribution of biomass burning emissions in the SOA formation during cold nights with high biomass burning activities. Concentrations of NO3 radicals as high as 25 ppt were measured in the perturbed chamber with an accompanying production of 0.2-1.2 &#956;g m-3 of organic nitrate. These results strongly indicate that the OA in biomass burning plumes can evolve rapidly even during wintertime periods with low photochemical activity.

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