Modeling organic aerosol from the oxidation of α-pinene in a Potential Aerosol Mass (PAM) chamber

Abstract. A model has been developed to simulate the formation and evolution of secondary organic aerosol (SOA) and was tested against data produced in a Potential Aerosol Mass (PAM) flow reactor and a large environmental chamber. The model framework is based on the two-dimensional volatility basis set approach (2D-VBS), in which SOA oxidation products in the model are distributed on the 2-D space of effective saturation concentration (Ci*) and oxygen-to-carbon ratio (O : C). The modeled organic aerosol mass concentrations (COA) and O : C agree with laboratory measurements within estimated uncertainties. However, while both measured and modeled O : C increase with increasing OH exposure as expected, the increase of modeled O : C is rapid at low OH exposure and then slows as OH exposure increases while the increase of measured O : C is initially slow and then accelerates as OH exposure increases. A global sensitivity analysis indicates that modeled COA values are most sensitive to the assumed values for the number of Ci* bins, the heterogeneous OH reaction rate coefficient, and the yield of first-generation products. Modeled SOA O : C values are most sensitive to the assumed O : C of first-generation oxidation products, the number of Ci* bins, the heterogeneous OH reaction rate coefficient, and the number of O : C bins. All these sensitivities vary as a function of OH exposure. The sensitivity analysis indicates that the 2D-VBS model framework may require modifications to resolve discrepancies between modeled and measured O : C as a function of OH exposure.

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Modeling organic aerosol from the oxidation of α-pinene in a Potential Aerosol Mass (PAM) chamber

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-5017-2013 ◽

2013 ◽

Vol 13 (9) ◽

pp. 5017-5031 ◽

Cited By ~ 20

Author(s):

S. Chen ◽

W. H. Brune ◽

A. T. Lambe ◽

P. Davidovits ◽

T. B. Onasch

Keyword(s):

Sensitivity Analysis ◽

Reaction Rate ◽

First Generation ◽

Rate Coefficient ◽

Organic Aerosol ◽

Oxidation Products ◽

Basis Set ◽

Model Framework ◽

Reaction Rate Coefficient ◽

Aerosol Mass

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Secondary organic aerosol production from pinanediol, a semi-volatile surrogate for first-generation oxidation products of monoterpenes

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-6171-2018 ◽

2018 ◽

Vol 18 (9) ◽

pp. 6171-6186 ◽

Cited By ~ 5

Author(s):

Penglin Ye ◽

Yunliang Zhao ◽

Wayne K. Chuang ◽

Allen L. Robinson ◽

Neil M. Donahue

Keyword(s):

Organic Compounds ◽

First Generation ◽

Secondary Organic Aerosol ◽

Organic Aerosol ◽

Particle Formation ◽

Oxidation Products ◽

Basis Set ◽

New Particle Formation ◽

Aerosol Mass ◽

Volatile Precursor

Abstract. We have investigated the production of secondary organic aerosol (SOA) from pinanediol (PD), a precursor chosen as a semi-volatile surrogate for first-generation oxidation products of monoterpenes. Observations at the CLOUD facility at CERN have shown that oxidation of organic compounds such as PD can be an important contributor to new-particle formation. Here we focus on SOA mass yields and chemical composition from PD photo-oxidation in the CMU smog chamber. To determine the SOA mass yields from this semi-volatile precursor, we had to address partitioning of both the PD and its oxidation products to the chamber walls. After correcting for these losses, we found OA loading dependent SOA mass yields from PD oxidation that ranged between 0.1 and 0.9 for SOA concentrations between 0.02 and 20 µg m−3, these mass yields are 2–3 times larger than typical of much more volatile monoterpenes. The average carbon oxidation state measured with an aerosol mass spectrometer was around −0.7. We modeled the chamber data using a dynamical two-dimensional volatility basis set and found that a significant fraction of the SOA comprises low-volatility organic compounds that could drive new-particle formation and growth, which is consistent with the CLOUD observations.

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Secondary organic aerosol production from pinanediol, a semi-volatile surrogate for first-generation oxidation products of monoterpenes

10.5194/acp-2017-943 ◽

2017 ◽

Cited By ~ 1

Author(s):

Penglin Ye ◽

Yunliang Zhao ◽

Wayne K. Chuang ◽

Allen L. Robinson ◽

Neil M. Donahue

Keyword(s):

Organic Compounds ◽

First Generation ◽

Secondary Organic Aerosol ◽

Organic Aerosol ◽

Particle Formation ◽

Oxidation Products ◽

Basis Set ◽

New Particle Formation ◽

Aerosol Mass ◽

Volatile Precursor

Abstract. We have investigated the production of secondary organic aerosol (SOA) from pinanediol (PD), a precursor chosen as a semi-volatile surrogate for first-generation oxidation products of monoterpenes. Observations at the CLOUD facility at CERN have shown that oxidation of organic compounds such as PD can be an important contributor to new-particle formation. Here we focus on SOA mass yields and chemical composition from PD photo-oxidation in the CMU smog chamber. To determine the SOA mass yields from this semi-volatile precursor, we had to address partitioning of both the PD and its oxidation products to the chamber walls. After correcting for these losses, we found OA loading dependent SOA mass yields from PD oxidation that ranged between 0.1 and 0.9 for SOA concentrations between 0.02 and 20 µg m−3, these mass yields are 2–3 times larger than typical of much more volatile monoterpenes. The average carbon oxidation state measured with an Aerosol Mass Spectrometer was around −0.7. We modeled the chamber data using a dynamical two-dimensional volatility basis set and found that a significant fraction of the SOA comprises low volatility organic compounds that could drive new-particle formation and growth, which is consistent with the CLOUD observations.

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Simulating the oxygen content of ambient organic aerosol with the 2D volatility basis set

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-7859-2011 ◽

2011 ◽

Vol 11 (15) ◽

pp. 7859-7873 ◽

Cited By ~ 66

Author(s):

B. N. Murphy ◽

N. M. Donahue ◽

C. Fountoukis ◽

S. N. Pandis

Keyword(s):

Oxygen Content ◽

Oxidation State ◽

First Generation ◽

Transport Model ◽

Organic Aerosol ◽

Basis Set ◽

Base Case ◽

Model Parameters ◽

High Oxygen Content ◽

Aerosol Mass

Abstract. A module predicting the oxidation state of organic aerosol (OA) has been developed using the two-dimensional volatility basis set (2D-VBS) framework. This model is an extension of the 1D-VBS framework and tracks saturation concentration and oxygen content of organic species during their atmospheric lifetime. The host model, a one-dimensional Lagrangian transport model, is used to simulate air parcels arriving at Finokalia, Greece during the Finokalia Aerosol Measurement Experiment in May 2008 (FAME-08). Extensive observations were collected during this campaign using an aerosol mass spectrometer (AMS) and a thermodenuder to determine the chemical composition and volatility, respectively, of the ambient OA. Although there are several uncertain model parameters, the consistently high oxygen content of OA measured during FAME-08 (O:C = 0.8) can help constrain these parameters and elucidate OA formation and aging processes that are necessary for achieving the high degree of oxygenation observed. The base-case model reproduces observed OA mass concentrations (measured mean = 3.1 μg m−3, predicted mean = 3.3 μg m−3) and O:C (predicted O:C = 0.78) accurately. A suite of sensitivity studies explore uncertainties due to (1) the anthropogenic secondary OA (SOA) aging rate constant, (2) assumed enthalpies of vaporization, (3) the volatility change and number of oxygen atoms added for each generation of aging, (4) heterogeneous chemistry, (5) the oxidation state of the first generation of compounds formed from SOA precursor oxidation, and (6) biogenic SOA aging. Perturbations in most of these parameters do impact the ability of the model to predict O:C well throughout the simulation period. By comparing measurements of the O:C from FAME-08, several sensitivity cases including a high oxygenation case, a low oxygenation case, and biogenic SOA aging case are found to unreasonably depict OA aging, keeping in mind that this study does not consider possibly important processes like fragmentation that may offset mass gains and affect the prediction bias. On the other hand, many of the cases chosen for this study predict average O:C estimates that are consistent with the observations, illustrating the need for more thorough experimental characterizations of OA parameters including the enthalpy of vaporization and oxidation state of the first generation of SOA products. The ability of the model to predict OA concentrations is less sensitive to perturbations in the model parameters than its ability to predict O:C. In this sense, quantifying O:C with a predictive model and constraining it with AMS measurements can reduce uncertainty in our understanding of OA formation and aging.

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Quantum functional sensitivity analysis for the collinear H+H2 reaction rate coefficient

The Journal of Chemical Physics ◽

10.1063/1.461906 ◽

1992 ◽

Vol 96 (5) ◽

pp. 3523-3530 ◽

Cited By ~ 18

Author(s):

Johnny Chang ◽

Nancy J. Brown ◽

Michael D’Mello ◽

Robert E. Wyatt ◽

Herschel Rabitz

Keyword(s):

Sensitivity Analysis ◽

Reaction Rate ◽

Rate Coefficient ◽

Reaction Rate Coefficient

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Simulating the oxygen content of ambient organic aerosol with the 2D volatility basis set

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-8553-2011 ◽

2011 ◽

Vol 11 (3) ◽

pp. 8553-8593 ◽

Cited By ~ 1

Author(s):

B. N. Murphy ◽

N. M. Donahue ◽

C. Fountoukis ◽

S. N. Pandis

Keyword(s):

Oxygen Content ◽

Oxidation State ◽

First Generation ◽

Transport Model ◽

Organic Aerosol ◽

Basis Set ◽

Base Case ◽

Model Parameters ◽

High Oxygen Content ◽

Aerosol Mass

Abstract. A module predicting the oxidation state of organic aerosol (OA) has been developed using the two-dimensional volatility basis set (2D-VBS) framework. This model is an extension of the 1D-VBS framework and tracks saturation concentration and oxygen content of organic species during their atmospheric lifetime. The host model, a one-dimensional Lagrangian transport model, is used to simulate air parcels arriving at Finokalia, Greece during the Finokalia Aerosol Measurement Experiment in May 2008 (FAME-08). Extensive observations were collected during this campaign using an aerosol mass spectrometer (AMS) and a thermodenuder to determine the chemical composition and volatility, respectively, of the ambient OA. Although there are several uncertain model parameters, the consistently high oxygen content of OA measured during FAME-08 (O:C = 0.8) can help constrain these parameters and elucidate OA formation and aging processes that are necessary for achieving the high degree of oxygenation observed. The base-case model reproduces observed OA mass concentrations (measured mean = 3.1 μg m−3, predicted mean = 3.3 μg m−3) and O:C ratio (predicted O:C = 0.78) accurately. A suite of sensitivity studies explore uncertainties due to (1) the anthropogenic secondary OA (SOA) aging rate constant, (2) assumed enthalpies of vaporization, (3) the volatility change and number of oxygen atoms added for each generation of aging, (4) heterogeneous chemistry, (5) the oxidation state of the first generation of compounds formed from SOA precursor oxidation, and (6) biogenic SOA aging. Perturbations in most of these parameters do impact the ability of the model to predict O:C ratios well throughout the simulation period. By comparing measurements of the O:C ratio from FAME-08, several sensitivity cases including a high oxygenation case, low oxygenation case, and biogenic SOA aging case are found to unreasonably depict OA aging. However, many of the cases chosen for this study predict average O:C ratios that are consistent with the observations, illustrating the need for more thorough experimental characterizations of OA parameters including the enthalpy of vaporization and oxidation state of the first generation of SOA products. The ability of the model to predict OA concentrations is less sensitive to perturbations in the model parameters than its ability to predict O:C ratios. In this sense, quantifying the O:C ratio with a predictive model and constraining it with AMS measurements can reduce uncertainty in our understanding of OA formation and aging.

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Development of a versatile source apportionment analysis based on positive matrix factorization: a case study of the seasonal variation of organic aerosol sources in Estonia

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-7279-2019 ◽

2019 ◽

Vol 19 (11) ◽

pp. 7279-7295 ◽

Cited By ~ 2

Author(s):

Athanasia Vlachou ◽

Anna Tobler ◽

Houssni Lamkaddam ◽

Francesco Canonaco ◽

Kaspar R. Daellenbach ◽

...

Keyword(s):

Matrix Factorization ◽

Organic Aerosol ◽

Positive Matrix Factorization ◽

Water Soluble ◽

Oxidation Products ◽

Positive Matrix ◽

Bootstrap Analysis ◽

Seasonal Behavior ◽

Yearly Cycle ◽

Aerosol Mass

Abstract. Bootstrap analysis is commonly used to capture the uncertainties of a bilinear receptor model such as the positive matrix factorization (PMF) model. This approach can estimate the factor-related uncertainties and partially assess the rotational ambiguity of the model. The selection of the environmentally plausible solutions, though, can be challenging, and a systematic approach to identify and sort the factors is needed. For this, comparison of the factors between each bootstrap run and the initial PMF output, as well as with externally determined markers, is crucial. As a result, certain solutions that exhibit suboptimal factor separation should be discarded. The retained solutions would then be used to test the robustness of the PMF output. Meanwhile, analysis of filter samples with the Aerodyne aerosol mass spectrometer and the application of PMF and bootstrap analysis on the bulk water-soluble organic aerosol mass spectra have provided insight into the source identification and their uncertainties. Here, we investigated a full yearly cycle of the sources of organic aerosol (OA) at three sites in Estonia: Tallinn (urban), Tartu (suburban) and Kohtla-Järve (KJ; industrial). We identified six OA sources and an inorganic dust factor. The primary OA types included biomass burning, dominant in winter in Tartu and accounting for 73 % ± 21 % of the total OA, primary biological OA which was abundant in Tartu and Tallinn in spring (21 % ± 8 % and 11 % ± 5 %, respectively), and two other primary OA types lower in mass. A sulfur-containing OA was related to road dust and tire abrasion which exhibited a rather stable yearly cycle, and an oil OA was connected to the oil shale industries in KJ prevailing at this site that comprises 36 % ± 14 % of the total OA in spring. The secondary OA sources were separated based on their seasonal behavior: a winter oxygenated OA dominated in winter (36 % ± 14 % for KJ, 25 % ± 9 % for Tallinn and 13 % ± 5 % for Tartu) and was correlated with benzoic and phthalic acid, implying an anthropogenic origin. A summer oxygenated OA was the main source of OA in summer at all sites (26 % ± 5 % in KJ, 41 % ± 7 % in Tallinn and 35 % ± 7 % in Tartu) and exhibited high correlations with oxidation products of a-pinene-like pinic acid and 3-methyl-1, 2, 3-butanetricarboxylic acid (MBTCA), suggesting a biogenic origin.

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Reaction Rate Coefficient of OH Radicals with d9-Butanol as a Function of Temperature

ACS Omega ◽

10.1021/acsomega.1c01942 ◽

2021 ◽

Author(s):

Amira Allani ◽

Yuri Bedjanian ◽

Dimitrios K. Papanastasiou ◽

Manolis N. Romanias

Keyword(s):

Reaction Rate ◽

Rate Coefficient ◽

Oh Radicals ◽

Reaction Rate Coefficient

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Constraining condensed-phase formation kinetics of secondary organic aerosol components from isoprene epoxydiols

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-1245-2016 ◽

2016 ◽

Vol 16 (3) ◽

pp. 1245-1254 ◽

Cited By ~ 31

Author(s):

T. P. Riedel ◽

Y.-H. Lin ◽

Z. Zhang ◽

K. Chu ◽

J. A. Thornton ◽

...

Keyword(s):

Aqueous Phase ◽

Atmospheric Aerosols ◽

Rate Constants ◽

Reaction Rate ◽

Secondary Organic Aerosol ◽

Organic Aerosol ◽

Heterogeneous Reactions ◽

Model Calculations ◽

Reaction Rate Constants ◽

Aerosol Mass

Abstract. Isomeric epoxydiols from isoprene photooxidation (IEPOX) have been shown to produce substantial amounts of secondary organic aerosol (SOA) mass and are therefore considered a major isoprene-derived SOA precursor. Heterogeneous reactions of IEPOX on atmospheric aerosols form various aerosol-phase components or "tracers" that contribute to the SOA mass burden. A limited number of the reaction rate constants for these acid-catalyzed aqueous-phase tracer formation reactions have been constrained through bulk laboratory measurements. We have designed a chemical box model with multiple experimental constraints to explicitly simulate gas- and aqueous-phase reactions during chamber experiments of SOA growth from IEPOX uptake onto acidic sulfate aerosol. The model is constrained by measurements of the IEPOX reactive uptake coefficient, IEPOX and aerosol chamber wall losses, chamber-measured aerosol mass and surface area concentrations, aerosol thermodynamic model calculations, and offline filter-based measurements of SOA tracers. By requiring the model output to match the SOA growth and offline filter measurements collected during the chamber experiments, we derive estimates of the tracer formation reaction rate constants that have not yet been measured or estimated for bulk solutions.

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Exploration of oxidative chemistry and secondary organic aerosol formation in the Amazon during the wet season: explicit modeling of the Manaus urban plume with GECKO-A

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-5995-2020 ◽

2020 ◽

Vol 20 (10) ◽

pp. 5995-6014 ◽

Cited By ~ 1

Author(s):

Camille Mouchel-Vallon ◽

Julia Lee-Taylor ◽

Alma Hodzic ◽

Paulo Artaxo ◽

Bernard Aumont ◽

...

Keyword(s):

Secondary Organic Aerosol ◽

Background Level ◽

Organic Aerosol ◽

Oxidation Products ◽

Box Model ◽

Basis Set ◽

Aerosol Formation ◽

Wet Season ◽

Urban Plume ◽

The Impact

Abstract. The GoAmazon 2014/5 field campaign took place in Manaus, Brazil, and allowed the investigation of the interaction between background-level biogenic air masses and anthropogenic plumes. We present in this work a box model built to simulate the impact of urban chemistry on biogenic secondary organic aerosol (SOA) formation and composition. An organic chemistry mechanism is generated with the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) to simulate the explicit oxidation of biogenic and anthropogenic compounds. A parameterization is also included to account for the reactive uptake of isoprene oxidation products on aqueous particles. The biogenic emissions estimated from existing emission inventories had to be reduced to match measurements. The model is able to reproduce ozone and NOx for clean and polluted situations. The explicit model is able to reproduce background case SOA mass concentrations but does not capture the enhancement observed in the urban plume. The oxidation of biogenic compounds is the major contributor to SOA mass. A volatility basis set (VBS) parameterization applied to the same cases obtains better results than GECKO-A for predicting SOA mass in the box model. The explicit mechanism may be missing SOA-formation processes related to the oxidation of monoterpenes that could be implicitly accounted for in the VBS parameterization.

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