scholarly journals Secondary organic aerosol model intercomparison based on secondary organic aerosol to odd oxygen ratio in Tokyo

2014 ◽  
Vol 119 (23) ◽  
pp. 13,489-13,505 ◽  
Author(s):  
Yu Morino ◽  
Kiyoshi Tanabe ◽  
Kei Sato ◽  
Toshimasa Ohara
Keyword(s):  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Model Intercomparison ◽  
Aerosol Model ◽  
Oxygen Ratio ◽  
Odd Oxygen

scholarly journals Correlation of secondary organic aerosol with odd oxygen in Mexico City

2008 ◽  
Vol 35 (15) ◽  
Author(s):  
Scott C. Herndon ◽  
Timothy B. Onasch ◽  
Ezra C. Wood ◽  
Jesse H. Kroll ◽  
Manjula R. Canagaratna ◽  
...  
Keyword(s):  
Mexico City ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Odd Oxygen

scholarly journals Investigation of the correlation between odd oxygen and secondary organic aerosol in Mexico City and Houston

2010 ◽  
Vol 10 (2) ◽  
pp. 3547-3604 ◽  
Author(s):  
E. C. Wood ◽  
M. R. Canagaratna ◽  
S. C. Herndon ◽  
J. H. Kroll ◽  
T. B. Onasch ◽  
...  
Keyword(s):  
Mexico City ◽  
Secondary Organic Aerosol ◽  
Formation Rate ◽  
Organic Aerosol ◽  
Ozone Production ◽  
Volatile Components ◽  
Petrochemical Plant ◽  
Plant Emissions ◽  
Photochemical Aging ◽  
Odd Oxygen

Abstract. Many recent models underpredict secondary organic aerosol (SOA) particulate matter (PM) concentrations in polluted regions, indicating serious deficiencies in the models' chemical mechanisms and/or missing SOA precursors. Since tropospheric photochemical ozone production is much better understood, we investigate the correlation of odd-oxygen ([Ox]≡[O3]+[NO2]) and the oxygenated component of organic aerosol (OOA), which is interpreted as a surrogate for SOA. OOA and Ox measured in Mexico City in 2006 and Houston in 2000 were well correlated in air masses where both species were formed on similar timescales (less than 8 h) and not well correlated when their formation timescales or location differed greatly. When correlated, the ratio of these two species ranged from 30 μg m−3 ppm−1 (STP) in Houston during time periods affected by large petrochemical plant emissions to as high as 160 μg m−3 ppm−1 in Mexico City, where typical values were near 120 μg m−3 ppm−1. On several days in Mexico City, the [OOA]/[Ox] ratio decreased by a factor of ~2 between 08:00 and 13:00 LT. This decrease is only partially attributable to evaporation of the least oxidized and most volatile components of OOA; differences in the diurnal emission trends and timescales for photochemical processing of SOA precursors compared to ozone precursors also likely contribute to the observed decrease. The extent of OOA oxidation increased with photochemical aging. Calculations of the ratio of the SOA formation rate to the Ox production rate using ambient VOC measurements and traditional laboratory SOA yields are lower than the observed [OOA]/[Ox] ratios by factors of 5 to 15, consistent with several other models' underestimates of SOA. Calculations of this ratio using emission factors for organic compounds from gasoline and diesel exhaust do not reproduce the observed ratio. Although not succesful in reproducing the atmospheric observations presented, modeling P(SOA)/P(Ox) can serve as a useful test of photochemical models using improved formulation mechanisms for SOA.

scholarly journals Evaluation of the atmospheric significance of multiphase reactions in atmospheric secondary organic aerosol formation

2005 ◽  
Vol 5 (10) ◽  
pp. 2823-2831 ◽  
Author(s):  
◽  
Keyword(s):  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Henry Constant ◽  
Oxidation Products ◽  
Individual Species ◽  
Aerosol Formation ◽  
Model Calculations ◽  
Aerosol Model ◽  
Sulfate Production ◽  
Multiphase Reactions

Abstract. In a simple conceptual cloud-aerosol model the mass of secondary organic aerosol (SOA) that may be formed in multiphase reaction in an idealized scenario involving two cloud cycles separated with a cloud-free period is evaluated. The conditions are set to those typical of continental clouds, and each parameter used in the model calculations is selected as a mean of available observational data of individual species for which the multiphase SOA formation route has been established. In the idealized setting gas and aqueous-phase reactions are both considered, but only the latter is expected to yield products of sufficiently low volatility to be retained by aerosol particles after the cloud dissipates. The key variable of the model is the Henry-constant which primarily determines how important multiphase reactions are relative to gas-phase photooxidation processes. The precursor considered in the model is assumed to already have some affinity to water, i.e. it is a compound having oxygen-containing functional group(s). As a principal model output an aerosol yield parameter is calculated for the multiphase SOA formation route as a function of the Henry-constant, and has been found to be significant already above H~103 M atm-1. Among the potential precursors that may be eligible for this mechanism based on their Henry constants, there are a suite of oxygenated compounds such as primary oxidation products of biogenic and anthropogenic hydrocarbons, including, for example, pinonaldehyde. Finally, the analogy of multiphase SOA formation to in-cloud sulfate production is exploited.

scholarly journals Updated aerosol module and its application to simulate secondary organic aerosols during IMPACT campaign May 2008

2013 ◽  
Vol 13 (13) ◽  
pp. 6289-6304 ◽  
Author(s):  
Y. P. Li ◽  
H. Elbern ◽  
K. D. Lu ◽  
E. Friese ◽  
A. Kiendler-Scharr ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Rural Site ◽  
Secondary Products ◽  
Product Model ◽  
Aerosol Model ◽  
Im Model ◽  
Chamber Studies ◽  
The Impact

Abstract. The formation of Secondary organic aerosol (SOA) was simulated with the Secondary ORGanic Aerosol Model (SORGAM) by a classical gas-particle partitioning concept, using the two-product model approach, which is widely used in chemical transport models. In this study, we extensively updated SORGAM including three major modifications: firstly, we derived temperature dependence functions of the SOA yields for aromatics and biogenic VOCs (volatile organic compounds), based on recent chamber studies within a sophisticated mathematic optimization framework; secondly, we implemented the SOA formation pathways from photo oxidation (OH initiated) of isoprene; thirdly, we implemented the SOA formation channel from NO3-initiated oxidation of reactive biogenic hydrocarbons (isoprene and monoterpenes). The temperature dependence functions of the SOA yields were validated against available chamber experiments, and the updated SORGAM with temperature dependence functions was evaluated with the chamber data. Good performance was found with the normalized mean error of less than 30%. Moreover, the whole updated SORGAM module was validated against ambient SOA observations represented by the summed oxygenated organic aerosol (OOA) concentrations abstracted from aerosol mass spectrometer (AMS) measurements at a rural site near Rotterdam, the Netherlands, performed during the IMPACT campaign in May 2008. In this case, we embedded both the original and the updated SORGAM module into the EURopean Air pollution and Dispersion-Inverse Model (EURAD-IM), which showed general good agreements with the observed meteorological parameters and several secondary products such as O3, sulfate and nitrate. With the updated SORGAM module, the EURAD-IM model also captured the observed SOA concentrations reasonably well especially those during nighttime. In contrast, the EURAD-IM model before update underestimated the observations by a factor of up to 5. The large improvements of the modeled SOA concentrations by updated SORGAM were attributed to the mentioned three modifications. Embedding the temperature dependence functions of the SOA yields, including the new pathways from isoprene photo oxidations, and switching on the SOA formation from NO3 initiated biogenic VOC oxidations, contributed to this enhancement by 10, 22 and 47%, respectively. However, the EURAD-IM model with updated SORGAM still clearly underestimated the afternoon SOA observations up to a factor of two.

scholarly journals Evaluation of the atmospheric significance of multiphase reactions in atmospheric secondary organic aerosol formation

2005 ◽  
Vol 5 (4) ◽  
pp. 4407-4428
Author(s):  
A. Gelencsér ◽  
Z. Varga
Keyword(s):  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Henry Constant ◽  
Oxidation Products ◽  
Individual Species ◽  
Aerosol Formation ◽  
Model Calculations ◽  
Aerosol Model ◽  
Sulfate Production ◽  
Multiphase Reactions

Abstract. In a simple conceptual cloud-aerosol model the mass of secondary organic aerosol (SOA) that may be formed in multiphase reaction in an idealized scenario involving two cloud cycles separated with a cloud-free period is evaluated. The conditions are set to those typical of continental clouds, and each parameter used in the model calculations is selected as a mean of available observational data of individual species for which the multiphase SOA formation route has been established. In the idealized setting gas and aqueous-phase reactions are both considered, but only the latter is expected to yield products of sufficiently low volatility to be retained by aerosol particles after the cloud dissipates. The key variable of the model is the Henry-constant which primarily determines how important multiphase reactions are relative to gas-phase photooxidation processes. The precursor considered in the model is assumed to already have some affinity to water, i.e. it is a compound having oxygen-containing functional group(s). As a principal model output an aerosol yield parameter is calculated for the multiphase SOA formation route as a function of the Henry-constant, and has been found to be significant already above H~103 M atm−1. Among the potential precursors that may be eligible for this mechanism based on their Henry constants, there are a suite of oxygenated compounds such as primary oxidation products of biogenic and anthropogenic hydrocarbons, including, for example, pinonaldehyde. Finally, the analogy of multiphase SOA formation to in-cloud sulfate production is exploited.

scholarly journals Updated aerosol module and its application to simulate secondary organic aerosols during IMPACT campaign May 2008

2013 ◽  
Vol 13 (3) ◽  
pp. 5961-6005 ◽  
Author(s):  
Y. P. Li ◽  
H. Elbern ◽  
K. D. Lu ◽  
E. Friese ◽  
A. Kiendler-Scharr ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Rural Site ◽  
Secondary Products ◽  
Product Model ◽  
Aerosol Model ◽  
Im Model ◽  
Chamber Studies ◽  
The Impact

Abstract. The formation of Secondary organic aerosol (SOA) was simulated with the Secondary ORGanic Aerosol Model (SORGAM) by a classical gas-particle partitioning concept, using the two-product model approach, which is widely used in chemical transport models. In this study, we extensively updated SORGAM including three major modifications: firstly, we derived temperature dependence functions of the SOA yields for aromatics and biogenic VOCs, based on recent chamber studies within a sophisticated mathematic optimization framework; secondly, we implemented the SOA formation pathways from photo oxidation (OH initiated) of isoprene; thirdly, we implemented the SOA formation channel from NO3-initiated oxidation of reactive biogenic hydrocarbons (isoprene and monoterpenes). The temperature dependence functions of the SOA yields were validated against available chamber experiments. Moreover, the whole updated SORGAM module was validated against ambient SOA observations represented by the summed oxygenated organic aerosol (OOA) concentrations abstracted from Aerosol Mass Spectrometer (AMS) measurements at a rural site near Rotterdam, the Netherlands, performed during the IMPACT campaign in May 2008. In this case, we embedded both the original and the updated SORGAM module into the EURopean Air pollution and Dispersion-Inverse Model (EURAD-IM), which showed general good agreements with the observed meteorological parameters and several secondary products such as O3, sulfate and nitrate. With the updated SORGAM module, the EURAD-IM model also captured the observed SOA concentrations reasonably well especially those during nighttime. In contrast, the EURAD-IM model before update underestimated the observations by a factor of up to 5. The large improvements of the modeled SOA concentrations by updated SORGAM were attributed to the mentioned three modifications. Embedding the temperature dependence functions of the SOA yields, including the new pathways from isoprene photo oxidations, and switching on the SOA formation from NO3 initiated biogenic VOCs oxidations contributed to this enhancement by 10%, 22% and 47%, respectively. However, the EURAD-IM model with updated SORGAM still clearly underestimated the afternoon SOA observations up to a factor of two. More work such as to improve the simulated OH concentrations under high VOCs and low NOx concentrations, further including the SOA formation from semi-volatile organic compounds, the correct aging process of aerosols, oligomerization process and the influence on the biogenic SOA by the anthropogenic SOA, are still required to fill the gap.

scholarly journals Modeling secondary organic aerosol in an urban area: application to Paris, France

2012 ◽  
Vol 12 (9) ◽  
pp. 23471-23511 ◽  
Author(s):  
F. Couvidat ◽  
Y. Kim ◽  
K. Sartelet ◽  
C. Seigneur ◽  
N. Marchand ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
City Center ◽  
Aerosol Model ◽  
Paris Area ◽  
Volatile Organic ◽  
Theoretical Mechanism ◽  
The City

Abstract. A secondary organic aerosol (SOA) model, H2O (Hydrophilic/Hydrophobic Organic), is evaluated over the Paris area. This model treats the formation of SOA with two kinds of surrogate species: hydrophilic species (which condense preferentially on an aqueous phase) and hydrophobic species (which condense only on an organic phase). These surrogates species are formed from the oxidation in the atmosphere of volatile organic compounds (VOC) by radicals (HO and NO3) and ozone. These VOC are either biogenic (isoprene, monoterpenes and sesquiterpenes) or anthropogenic (mainly aromatic compounds). This model includes the formation of aerosols from different precursors (biogenic precursors, aromatics), and semi-volatile organic compounds (SVOC) from traffic. The H2O aerosol model was incorporated into the Polyphemus air quality modeling platform and applied to the Paris area and evaluated by comparison to measurements performed during the Megapoli campaign in July 2009. The comparison to measurements in the suburbs and in the city center of Paris shows that the model gives satisfactory results for both elemental carbon (EC) and organic carbon (OC). However, the model gives a peak of OC concentrations in the morning due to high emissions from traffic, which does not appear in measurements. Uncertainties in the modeled temperature, which can affect the gas-particle partitioning, in the partitioning of primary SVOC or underestimation of primary organic aerosol (POA) evaporation by the model could explain the differences between model and measurements. Moreover, using a theoretical mechanism for the oxidation of primary SVOC and intermediate volatility organic compounds (IVOC), POA concentrations were found to be likely overestimated by models due to the use of simple partitioning constants (which do not take into account the affinity of a compound with the liquid aerosol solution) or due to the assumption that the organic aerosol solution is a one-phase ideal solution. The organic aerosol in the city center of Paris was found to be originating mostly from distant sources with only 30 to 38% due to local sources.

scholarly journals simpleGAMMA v1.0 – a reduced model of secondary organic aerosol formation in the aqueous aerosol phase (aaSOA)

2015 ◽  
Vol 8 (6) ◽  
pp. 1821-1829 ◽  
Author(s):  
J. L. Woo ◽  
V. F. McNeill
Keyword(s):  
Atmospheric Chemistry ◽  
Secondary Organic Aerosol ◽  
Measurement Data ◽  
Organic Aerosol ◽  
Reaction Scheme ◽  
Water Soluble ◽  
Mechanism Analysis ◽  
Aerosol Formation ◽  
Computationally Efficient ◽  
Aerosol Model

Abstract. There is increasing evidence that the uptake and aqueous processing of water-soluble volatile organic compounds (VOCs) by wet aerosols or cloud droplets is an important source of secondary organic aerosol (SOA). We recently developed GAMMA (Gas–Aerosol Model for Mechanism Analysis), a zero-dimensional kinetic model that couples gas-phase and detailed aqueous-phase atmospheric chemistry for speciated prediction of SOA and organosulfate formation in cloud water or aqueous aerosols. Results from GAMMA simulations of SOA formation in aerosol water (aaSOA) (McNeill et al., 2012) indicate that it is dominated by two pathways: isoprene epoxydiol (IEPOX) uptake followed by ring-opening chemistry (under low-NOx conditions) and glyoxal uptake. This suggested that it is possible to model the majority of aaSOA mass using a highly simplified reaction scheme. We have therefore developed a reduced version of GAMMA, simpleGAMMA. Close agreement in predicted aaSOA mass is observed between simpleGAMMA and GAMMA under all conditions tested (between pH 1–4 and RH 40–80 %) after 12 h of simulation. simpleGAMMA is computationally efficient and suitable for coupling with larger-scale atmospheric chemistry models or analyzing ambient measurement data.

scholarly journals In-cloud oxalate formation in the global troposphere: a 3-D modeling study

2011 ◽  
Vol 11 (1) ◽  
pp. 485-530 ◽  
Author(s):  
S. Myriokefalitakis ◽  
K. Tsigaridis ◽  
N. Mihalopoulos ◽  
J. Sciare ◽  
A. Nenes ◽  
...  
Keyword(s):  
Gas Phase ◽  
Aqueous Phase ◽  
Secondary Organic Aerosol ◽  
Transport Model ◽  
Organic Aerosol ◽  
Chemical Oxidation ◽  
Turnover Time ◽  
Chemical Production ◽  
Aerosol Model ◽  
Phase Chemistry

Abstract. Organic acids attract increasing attention as contributors to atmospheric acidity, secondary organic aerosol mass and aerosol hygroscopicity. Oxalic acid is globally the most abundant dicarboxylic acid, formed via chemical oxidation of gas-phase precursors in the aqueous phase of aerosols and droplets. Its lifecycle and atmospheric global distribution remain highly uncertain and are the focus of this study. The first global spatial and temporal distribution of oxalate, simulated using a state-of-the-art aqueous phase chemical scheme embedded within the global 3-dimensional chemistry/transport model TM4-ECPL, is here presented. The model accounts for comprehensive gas-phase chemistry and its coupling with major aerosol constituents (including secondary organic aerosol). Model results are consistent with ambient observations of oxalate at rural and remote locations (slope = 0.83 ± 0.06, r2 = 0.67, N = 106) and suggest that aqueous phase chemistry contributes significantly to the global atmospheric burden of secondary organic aerosol. In TM4-ECPL most oxalate is formed in-clouds and less than 10% is produced in aerosol water. About 61% of the oxalate is removed via wet deposition, 35% by in-cloud reaction with hydroxyl radical and 4% by dry deposition. The global oxalate net chemical production is calculated to be about 17–27 Tg yr−1 with almost 91% originating from biogenic hydrocarbons, mainly isoprene. This condensed phase net source of oxalate in conjunction with a global mean turnover time against deposition of about 5 days, maintain oxalate's global tropospheric burden of 0.24–0.39 Tg that is about 13–19% of calculated total organic aerosol burden.

scholarly journals Isoprene-derived secondary organic aerosol in the global aerosol–chemistry–climate model ECHAM6.3.0–HAM2.3–MOZ1.0

2018 ◽  
Vol 11 (8) ◽  
pp. 3235-3260 ◽  
Author(s):  
Scarlet Stadtler ◽  
Thomas Kühn ◽  
Sabine Schröder ◽  
Domenico Taraborrelli ◽  
Martin G. Schultz ◽  
...  
Keyword(s):  
Climate Model ◽  
Secondary Organic Aerosol ◽  
Ph Value ◽  
Organic Aerosol ◽  
Chemical Mechanism ◽  
Vapor Pressures ◽  
Model Framework ◽  
Aerosol Model ◽  
Single Precursor ◽  
Isoprene Oxidation

Abstract. Within the framework of the global chemistry climate model ECHAM–HAMMOZ, a novel explicit coupling between the sectional aerosol model HAM-SALSA and the chemistry model MOZ was established to form isoprene-derived secondary organic aerosol (iSOA). Isoprene oxidation in the chemistry model MOZ is described by a semi-explicit scheme consisting of 147 reactions embedded in a detailed atmospheric chemical mechanism with a total of 779 reactions. Semi-volatile and low-volatile compounds produced during isoprene photooxidation are identified and explicitly partitioned by HAM-SALSA. A group contribution method was used to estimate their evaporation enthalpies and corresponding saturation vapor pressures, which are used by HAM-SALSA to calculate the saturation concentration of each iSOA precursor. With this method, every single precursor is tracked in terms of condensation and evaporation in each aerosol size bin. This approach led to the identification of dihydroxy dihydroperoxide (ISOP(OOH)2) as a main contributor to iSOA formation. Further, the reactive uptake of isoprene epoxydiols (IEPOXs) and isoprene-derived glyoxal were included as iSOA sources. The parameterization of IEPOX reactive uptake includes a dependency on aerosol pH value. This model framework connecting semi-explicit isoprene oxidation with explicit treatment of aerosol tracers leads to a global annual average isoprene SOA yield of 15 % relative to the primary oxidation of isoprene by OH, NO3 and ozone. With 445.1 Tg (392.1 Tg C) isoprene emitted, an iSOA source of 138.5 Tg (56.7 Tg C) is simulated. The major part of iSOA in ECHAM–HAMMOZ is produced by IEPOX at 42.4 Tg (21.0 Tg C) and ISOP(OOH)2 at 78.0 Tg (27.9 Tg C). The main sink process is particle wet deposition, which removes 133.6 (54.7 Tg C). The average iSOA burden reaches 1.4 Tg (0.6 Tg C) in the year 2012.

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