Is there an aerosol signature of chemical cloud processing?

Abstract. The formation of sulfate and secondary organic aerosol mass in the aqueous phase (aqSOA) of cloud and fog droplets can significantly contribute to ambient aerosol mass. While tracer compounds give evidence that aqueous-phase processing occurred, they do not reveal the extent to which particle properties have been modified in terms of mass, chemical composition, hygroscopicity, and oxidation state. We analyze data from several field experiments and model studies for six air mass types (urban, biogenic, marine, wild fire biomass burning, agricultural biomass burning, and background air) using aerosol size and composition measurements for particles 13–850 nm in diameter. We focus on the trends of changes in mass, hygroscopicity parameter κ, and oxygen-to-carbon (O ∕ C) ratio due to chemical cloud processing. We find that the modification of these parameters upon cloud processing is most evident in urban, marine, and biogenic air masses, i.e., air masses that are more polluted than very clean air (background air) but cleaner than heavily polluted plumes as encountered during biomass burning. Based on these trends, we suggest that the mass ratio (Rtot) of the potential aerosol sulfate and aqSOA mass to the initial aerosol mass can be used to predict whether chemical cloud processing will be detectable. Scenarios in which this ratio exceeds Rtot∼0.5 are the most likely ones in which clouds can significantly change aerosol parameters. It should be noted that the absolute value of Rtot depends on the considered size range of particles. Rtot is dominated by the addition of sulfate (Rsulf) in all scenarios due to the more efficient conversion of SO2 to sulfate compared to aqSOA formation from organic gases. As the formation processes of aqSOA are still poorly understood, the estimate of RaqSOA is likely associated with large uncertainties. Comparison to Rtot values as calculated for ambient data at different locations validates the applicability of the concept to predict a chemical cloud-processing signature in selected air masses.

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Is there an aerosol signature of cloud processing?

10.5194/acp-2018-475 ◽

2018 ◽

Author(s):

Barbara Ervens ◽

Armin Sorooshian ◽

Abdulnoman M. Aldhaif ◽

Taylor Shingler ◽

Ewan Crosbie ◽

...

Keyword(s):

Aqueous Phase ◽

Biomass Burning ◽

Field Experiments ◽

Air Masses ◽

Model Studies ◽

Cloud Processing ◽

Aerosol Mass ◽

Analyse Data ◽

Air Mass Types ◽

Background Air

Abstract. The formation of sulfate and secondary organic aerosol mass in the aqueous phase (aqSOA) of cloud and fog droplets can significantly contribute to ambient aerosol mass. While tracer compounds give evidence that aqueous phase processing occurred, they do not reveal the extent to which particle properties have been modified in terms of mass, chemical composition, hygroscopicity and oxidation state. We analyse data from several field experiments and model studies for six air mass types (urban, biogenic, marine, wild fire biomass burning, agricultural biomass burning and background air). We focus on the trends of changes in mass, hygroscopicity parameter κ, and oxygen-to-carbon (O / C) ratio due to cloud processing. We find that the modification of these parameters upon cloud-processing is most evident in urban, marine and biogenic air masses, i.e. air masses that are more polluted than very clean air (background air) but cleaner than heavily polluted plumes as encountered during biomass burning. Based on these trends, we suggest that the mass ratio (Rtot) of the potential aerosol sulfate and aqSOA mass to the initial aerosol mass can be used to predict whether cloud processing will be detectable. Scenarios where this ratio exceeds Rtot ~ 2 are the most likely ones where clouds can significantly change aerosol parameters. Comparison to Rtot values as calculated for ambient data at different locations confirm the applicability of the concept to predict a cloud-processing signature in selected air masses.

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Processing of biomass burning aerosol in the Eastern Mediterranean during summertime

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-25969-2013 ◽

2013 ◽

Vol 13 (10) ◽

pp. 25969-25999 ◽

Cited By ~ 2

Author(s):

A. Bougiatioti ◽

I. Stavroulas ◽

E. Kostenidou ◽

P. Zarmpas ◽

C. Theodosi ◽

...

Keyword(s):

Chemical Composition ◽

Biomass Burning ◽

Eastern Mediterranean ◽

Late Summer ◽

Organic Aerosol ◽

High Temporal Resolution ◽

Night Time ◽

Air Masses ◽

Aerosol Mass ◽

Atmospheric Processing

Abstract. The aerosol chemical composition in air masses affected by wildfires from the Greek islands of Chios, Euboea and Andros, the Dalmatian Coast and Sicily, during late summer of 2012 was characterized at the remote background site of Finokalia, Crete. Air masses were transported several hundreds of kilometers, arriving at the measurement station after approximately half a day of transport, mostly during night-time. The chemical composition of the particulate matter was studied by different high temporal resolution instruments, including an Aerosol Chemical Speciation Monitor (ACSM) and a seven-wavelength aethalometer. Despite the large distance from emission and long atmospheric processing, a clear biomass burning organic aerosol (BBOA) profile containing characteristic markers is derived from BC measurements and Positive Matrix Factorization (PMF) analysis of the ACSM mass spectra. The ratio of fresh to aged BBOA decreases with increasing atmospheric processing time and BBOA components appear to be converted to oxygenated organic aerosol (OOA). Given that the smoke was mainly transported overnight, it appears that the processing can take place in the dark. These results show that a significant fraction of the BBOA loses its characteristic AMS signature and is transformed to OOA in less than a day. This implies that biomass burning can contribute almost half of the organic aerosol mass in the area during summertime.

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Modelling the Tropospheric Multiphase Chemistry of Biomass Burning Trace Compounds Using the Chemical Aqueous Phase Radical Mechanism (CAPRAM)

10.5194/egusphere-egu21-10731 ◽

2021 ◽

Author(s):

Lin He ◽

Erik Hans Hoffmann ◽

Andreas Tilgner ◽

Hartmut Herrmann

Keyword(s):

Aqueous Phase ◽

Biomass Burning ◽

Flash Photolysis ◽

Laser Flash Photolysis ◽

Laser Flash ◽

Radical Mechanism ◽

Aerosol Formation ◽

Detailed Model ◽

Model Studies ◽

Trace Species

Biomass burning (BB) is a significant contributor to air pollution on global, regional and local scale with impacts on air quality, public health and climate. Anhydrosugars (levoglucosan, mannosan and galactocan) and methoxyphenols (guaiacol, creosol, etc.) are important tracer compounds emitted through biomass burning. Once emitted, they can undergo complex multiphase chemistry in the atmosphere contributing to secondary organic aerosol formation. However, their chemical multiphase processing is not yet well understood and investigated by models. Therefore, the present study aimed at a better understanding of the multiphase chemistry of these BB trace species by means of detailed model studies with a new developed detailed chemical CAPRAM biomass burning module (CAPRAM-BB). This module was developed based on the kinetic data from the laser flash photolysis measurements in our lab at TROPOS and other literature studies. The developed CAPRAM-BB module includes 2991 reactions (thereof 9 phase transfers and 2982 aqueous-phase reactions). By coupling with the multiphase chemistry mechanism MCMv3.2/CAPRAM4.0 and the extended CAPRAM aromatics (CAPRAM-AM1.0) and halogen modules (CAPRAM-HM3.0), it is being applied for some residential wood burning cases in Europe and wildfire cases in the US. Our model results show that the BB chemistry could significantly affect the budgets of important atmospheric oxidants such as H2O2 and HONO, and contribute to the SOA formation especially the fraction of brown carbon and substituted organic acids.

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Overview of aerosol properties associated with air masses sampled by the ATR-42 during the EUCAARI campaign (2008)

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-4877-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 4877-4893 ◽

Cited By ~ 9

Author(s):

S. Crumeyrolle ◽

A. Schwarzenboeck ◽

J. C. Roger ◽

K. Sellegri ◽

J. F. Burkhart ◽

...

Keyword(s):

Cross Sections ◽

Aerosol Particles ◽

Qualitative Evaluation ◽

Cloud Microphysics ◽

Air Masses ◽

The North ◽

Aerosol Mass ◽

Aerosol Parameters ◽

Scattering Cross Sections ◽

Mass Concentrations

Abstract. Within the frame of the European Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) project, the Météo-France aircraft ATR-42 performed 22 research flights over central Europe and the North Sea during the intensive observation period in May 2008. For the campaign, the ATR-42 was equipped to study the aerosol physical, chemical, hygroscopic and optical properties, as well as cloud microphysics. For the 22 research flights, retroplume analyses along the flight tracks were performed with FLEXPART in order to classify air masses into five sectors of origin, allowing for a qualitative evaluation of emission influence on the respective air parcel. This study shows that the extensive aerosol parameters (aerosol mass and number concentrations) show vertical decreasing gradients and in some air masses maximum mass concentrations (mainly organics) in an intermediate layer (1–3 km). The observed mass concentrations (in the boundary layer (BL): between 10 and 30 μg m−3; lower free troposphere (LFT): 0.8 and 14 μg m−3) are high especially in comparison with the 2015 European norms for PM2.5 (25 μg m−3) and with previous airborne studies performed over England (Morgan et al., 2009; McMeeking et al., 2012). Particle number size distributions show a larger fraction of particles in the accumulation size range in the LFT compared to BL. The chemical composition of submicron aerosol particles is dominated by organics in the BL, while ammonium sulphate dominates the submicron aerosols in the LFT, especially in the aerosol particles originated from north-eastern Europe (~ 80%), also experiencing nucleation events along the transport. As a consequence, first the particle CCN acting ability, shown by the CCN/CN ratio, and second the average values of the scattering cross sections of optically active particles (i.e. scattering coefficient divided by the optical active particle concentration) are increased in the LFT compared to BL.

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Impact of Aerosol-Cloud Cycling on Aqueous Secondary Organic Aerosol Formation

10.20944/preprints201909.0319.v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

William G. Tsui ◽

Joseph L. Woo ◽

V. Faye McNeill

Keyword(s):

Organic Acids ◽

Aqueous Phase ◽

Atmospheric Aerosols ◽

Organic Material ◽

Time Of Day ◽

Aerosol Formation ◽

Cloud Processing ◽

Aerosol Mass ◽

Phase Chemistry ◽

The Impact

Chemical processing of organic material in aqueous atmospheric aerosols and cloudwater is known to form secondary organic aerosols (SOA), although the extent to which each of these processes contributes to total aerosol mass is unclear. In this study, we use GAMMA 5.0, a photochemical box model with coupled gas and aqueous-phase chemistry, to consider the impact of aqueous organic reactions in both aqueous aerosols and clouds on isoprene epoxydiol (IEPOX) SOA over a range of pH for both aqueous phases, including cycling between cloud and aerosol within a single simulation. Low-pH aqueous aerosol, in the absence of organic coatings or other morphology which may limit uptake of IEPOX, is found to be an efficient source of IEPOX SOA, consistent with previous work. Cloudwater at pH 4 or lower is also found to be a potentially significant source of IEPOX SOA. This phenomenon is primarily attributed to the relatively high uptake of IEPOX to clouds as a result of higher water content in clouds as compared to aerosol. For more acidic cloudwater, the aqueous organic material is comprised primarily of IEPOX SOA and lower-volatility organic acids. For both cloudwater and aqueous aerosol, pH is the most significant factor considered in this study in determining the mass of aqueous phase organic acids and IEPOX SOA. Other factors, such as the time of day or sequence of aerosol-to-cloud or cloud-to-aerosol transitions, contribute to less than 15% difference in the final aqSOA fractional composition. The potential significance of cloud processing as a contributor to IEPOX SOA production could account for discrepancies between predicted IEPOX SOA mass from atmospheric models and measured ambient IEPOX SOA mass, or observations of IEPOX SOA in locations where mass transfer limitations are expected in aerosol particles.

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Modeling the Tropospheric Multiphase Chemistry of Biomass Burning Trace Compounds Using the Chemical Aqueous Phase Radical Mechanism (CAPRAM)

10.5194/dach2022-171 ◽

2021 ◽

Author(s):

Lin He ◽

Erik H. Hoffmann ◽

Andreas Tilgner ◽

Hartmut Herrmann

Keyword(s):

Aqueous Phase ◽

Biomass Burning ◽

Organic Aerosol ◽

Local Scale ◽

Radical Mechanism ◽

Laboratory Measurements ◽

Detailed Model ◽

Model Studies ◽

The Us ◽

Trace Compounds

Biomass burning (BB) is a significant contributor to air pollution on global, regional and local scale with impacts on air quality, public health and climate. Anhydrosugars and methoxyphenols are key tracers emitted through BB. Once emitted, they can undergo complex multiphase chemistry in the atmosphere contributing to secondary organic aerosol (SOA) formation. However, their chemical multiphase processing is not yet well understood and investigated by models. Thus, the present study aimed at a better understanding of the multiphase chemistry of these BB tracers by detailed model studies with a new developed CAPRAM biomass burning module (CAPRAM-BBM).This module was developed based on the kinetic data from our laboratory measurements at TROPOS and other literature studies. The developed CAPRAM-BBM includes 2991 reactions (9 phase transfers and 2982 aqueous-phase reactions). By coupling with the multiphase chemistry mechanism MCMv3.2/CAPRAM4.0 and the extended CAPRAM aromatics (CAPRAM-AM1.0) and halogen modules (CAPRAM-HM3.0), itis being applied for residential wood burning cases in Europeand wildfire cases in the US. Our model results show that levoglucosan and vanillin are effectively oxidized under cloud conditions. Furthermore, the results demonstrate that the chemistry of BB tracers can affect the budgets of key oxidants such as H2O2, and contribute to the SOA formation especially by increasing the fraction of brown carbon and substituted organic acids.

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Processing of biomass-burning aerosol in the eastern Mediterranean during summertime

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-4793-2014 ◽

2014 ◽

Vol 14 (9) ◽

pp. 4793-4807 ◽

Cited By ~ 87

Author(s):

A. Bougiatioti ◽

I. Stavroulas ◽

E. Kostenidou ◽

P. Zarmpas ◽

C. Theodosi ◽

...

Keyword(s):

Chemical Composition ◽

Biomass Burning ◽

Eastern Mediterranean ◽

Late Summer ◽

Organic Aerosol ◽

High Temporal Resolution ◽

Air Masses ◽

Aerosol Mass ◽

Aerosol Mass Spectrometry ◽

Atmospheric Processing

Abstract. The aerosol chemical composition in air masses affected by wildfires from the Greek islands of Chios, Euboea and Andros, the Dalmatian Coast and Sicily, during late summer of 2012 was characterized at the remote background site of Finokalia, Crete. Air masses were transported several hundreds of kilometers, arriving at the measurement station after approximately half a day of transport, mostly during nighttime. The chemical composition of the particulate matter was studied by different high-temporal-resolution instruments, including an aerosol chemical speciation monitor (ACSM) and a seven-wavelength aethalometer. Despite the large distance from emission and long atmospheric processing, a clear biomass-burning organic aerosol (BBOA) profile containing characteristic markers is derived from BC (black carbon) measurements and positive matrix factorization (PMF) analysis of the ACSM organic mass spectra. The ratio of fresh to aged BBOA decreases with increasing atmospheric processing time and BBOA components appear to be converted to oxygenated organic aerosol (OOA). Given that the smoke was mainly transported overnight, it appears that the processing can take place in the dark. These results show that a significant fraction of the BBOA loses its characteristic AMS (aerosol mass spectrometry) signature and is transformed to OOA in less than a day. This implies that biomass burning can contribute almost half of the organic aerosol mass in the area during periods with significant fire influence.

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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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Source attributions of pollution to the Western Arctic during the NASA ARCTAS field campaign

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-4707-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 4707-4721 ◽

Cited By ~ 49

Author(s):

H. Bian ◽

P. R. Colarco ◽

M. Chin ◽

G. Chen ◽

J. M. Rodriguez ◽

...

Keyword(s):

Biomass Burning ◽

Field Experiments ◽

Transport Model ◽

Background Level ◽

Anthropogenic Emissions ◽

Airborne Measurements ◽

Ch4 Production ◽

Regional Sources ◽

Western Arctic ◽

Co Concentrations

Abstract. We use the NASA GEOS-5 transport model with tagged tracers to investigate the contributions of different regional sources of CO and black carbon (BC) to their concentrations in the Western Arctic (i.e., 50–90° N and 190–320° E) in spring and summer 2008. The model is evaluated by comparing the results with airborne measurements of CO and BC from the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaigns to demonstrate the strengths and limitations of our simulations. We also examine the reliability of tagged CO tracers in characterizing air mass origins using the measured fossil fuel tracer of dichloromethane and the biomass burning tracer of acetonitrile. Our tagged CO simulations suggest that most of the enhanced CO concentrations (above background level from CH4 production) observed during April originate from Asian anthropogenic emissions. Boreal biomass burning emissions and Asian anthropogenic emissions are of similar importance in July domain wise, although the biomass burning CO fraction is much larger in the area of the ARCTAS field experiments. The fraction of CO from Asian anthropogenic emissions is larger in spring than in summer. European sources make up no more than 10% of CO levels in the campaign domain during either period. Comparisons of CO concentrations along the flight tracks with regional averages from GEOS-5 show that the along-track measurements are representative of the concentrations within the large domain of the Western Arctic in April but not in July.

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Oxidation of substituted aromatic hydrocarbons in the tropospheric aqueous phase: kinetic mechanism development and modelling

Physical Chemistry Chemical Physics ◽

10.1039/c7cp08576a ◽

2018 ◽

Vol 20 (16) ◽

pp. 10960-10977 ◽

Cited By ~ 17

Author(s):

Erik H. Hoffmann ◽

Andreas Tilgner ◽

Ralf Wolke ◽

Olaf Böge ◽

Arno Walter ◽

...

Keyword(s):

Aqueous Phase ◽

Aromatic Hydrocarbons ◽

Aromatic Compounds ◽

Kinetic Data ◽

Kinetic Mechanism ◽

Detailed Model ◽

Model Studies ◽

Phase Chemistry

An aqueous-phase chemistry mechanism for the oxidation of aromatic compounds in the atmosphere is developed based on available kinetic data. Detailed model studies successfully describe the oxidation and functionalization of monoaromatic compounds in the atmosphere.

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