scholarly journals Oligomer formation in the troposphere: from experimental knowledge to 3-D modeling

2016 ◽  
Vol 9 (4) ◽  
pp. 1361-1382 ◽  
Author(s):  
Vincent Lemaire ◽  
Isabelle Coll ◽  
Florian Couvidat ◽  
Camille Mouchel-Vallon ◽  
Christian Seigneur ◽  
...  
Keyword(s):  
Air Quality ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Kinetic Process ◽  
Critical Element ◽  
Order Kinetic ◽  
Continental Scale ◽  
Oligomer Formation ◽  
Modeling Approach ◽  
Ph Dependent

Abstract. The organic fraction of atmospheric aerosols has proven to be a critical element of air quality and climate issues. However, its composition and the aging processes it undergoes remain insufficiently understood. This work builds on laboratory knowledge to simulate the formation of oligomers from biogenic secondary organic aerosol (BSOA) in the troposphere at the continental scale. We compare the results of two different modeling approaches, a first-order kinetic process and a pH-dependent parameterization, both implemented in the CHIMERE air quality model (AQM) (www.lmd.polytechnique.fr/chimere), to simulate the spatial and temporal distribution of oligomerized secondary organic aerosol (SOA) over western Europe. We also included a comparison of organic carbon (OC) concentrations at two EMEP (European Monitoring and Evaluation Programme) stations. Our results show that there is a strong dependence of the results on the selected modeling approach: while the irreversible kinetic process leads to the oligomerization of about 50 % of the total BSOA mass, the pH-dependent approach shows a broader range of impacts, with a strong dependency on environmental parameters (pH and nature of aerosol) and the possibility for the process to be reversible. In parallel, we investigated the sensitivity of each modeling approach to the representation of SOA precursor solubility (Henry's law constant values). Finally, the pros and cons of each approach for the representation of SOA aging are discussed and recommendations are provided to improve current representations of oligomer formation in AQMs.

scholarly journals Oligomer formation in the troposphere: from experimental knowledge to 3-D modeling

2015 ◽  
Vol 8 (10) ◽  
pp. 9229-9279
Author(s):  
V. Lemaire ◽  
I. Coll ◽  
F. Couvidat ◽  
C. Mouchel-Vallon ◽  
C. Seigneur ◽  
...  
Keyword(s):  
Air Quality ◽  
Strong Dependence ◽  
Kinetic Process ◽  
Critical Element ◽  
Order Kinetic ◽  
Air Quality Model ◽  
Continental Scale ◽  
Oligomer Formation ◽  
Modeling Approach ◽  
Ph Dependent

Abstract. The organic fraction of atmospheric aerosols has proven to be a critical element of air quality and climate issues. However, its composition and the aging processes it undergoes remain insufficiently understood. This work builds on laboratory knowledge to simulate the formation of oligomers from biogenic secondary organic aerosol (BSOA) in the troposphere at the continental scale. We compare the results of two different modeling approaches, a 1st-order kinetic process and a pH-dependent parameterization, both implemented in the CHIMERE air quality model (AQM), to simulate the spatial and temporal distribution of oligomerized SOA over western Europe. Our results show that there is a strong dependence of the results on the selected modeling approach: while the irreversible kinetic process leads to the oligomerization of about 50 % of the total BSOA mass, the pH-dependent approach shows a broader range of impacts, with a strong dependency on environmental parameters (pH and nature of aerosol) and the possibility for the process to be reversible. In parallel, we investigated the sensitivity of each modeling approach to the representation of SOA precursor solubility (Henry's law constant values). Finally, the pros and cons of each approach for the representation of SOA aging are discussed and recommendations are provided to improve current representations of oligomer formation in AQMs.

scholarly journals Additional Benefits of Federal Air-Quality Rules: Model Estimates of Controllable Biogenic Secondary Organic Aerosol

2018 ◽  
Vol 52 (16) ◽  
pp. 9254-9265 ◽  
Author(s):  
Annmarie G. Carlton ◽  
Havala O. T. Pye ◽  
Kirk R. Baker ◽  
Christopher J. Hennigan
Keyword(s):  
Air Quality ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol

scholarly journals Secondary Organic Aerosol from Atmospheric Photooxidation of Indole

2017 ◽  
Author(s):  
Julia Montoya ◽  
Jeremy R. Horne ◽  
Mallory L. Hinks ◽  
Lauren T. Fleming ◽  
Veronique Perraud ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Air Quality ◽  
Chemical Composition ◽  
High Resolution ◽  
Secondary Organic Aerosol ◽  
High Resolution Mass Spectrometry ◽  
Organic Aerosol ◽  
Scanning Mobility Particle Sizer ◽  
High Resolution Mass ◽  
Resolution Mass

Abstract. Indole is a heterocyclic compound emitted by various plant species under stressed conditions or during flowering events. The formation, optical properties, and chemical composition of secondary organic aerosol (SOA) formed by low-NOx photooxidation of indole were investigated. The SOA yield (1.1 ± 0.3) was estimated from measuring the particle mass concentration with a scanning mobility particle sizer (SMPS) and correcting it for the wall loss effects. The SOA particles were collected on filters and analysed offline with UV-Vis spectrophotometry to measure the mass absorption coefficient (MAC) of the bulk sample. The samples were visibly brown and had MAC values of ~7 m2/g at λ = 300 nm and ~2 m2/g at λ = 400 nm, comparable to strongly absorbing brown carbon emitted from biomass burning. The chemical composition of SOA was examined with several mass spectrometry methods. The direct analysis in real time mass spectrometry (DART-MS) and nanospray desorption electrospray high resolution mass spectrometry (nano-DESI-HRMS) were used to provide information about the overall distribution of SOA compounds. High performance liquid chromatography, coupled to photodiode array spectrophotometry and high resolution mass spectrometry (HPLC-PDA-HRMS) was used to identify chromophoric compounds. Indole derivatives, such as tryptanthrin, indirubin, indigo dye, and indoxyl red were found to contribute significantly to the visible absorption spectrum of indole SOA. The potential effect of indole SOA on air quality was explored with the airshed model, which found elevated concentrations of indole SOA during the afternoon hours contributing considerably to the total organic aerosol under selected scenarios. Because of its high MAC values, indole SOA can contribute to decreased visibility and poor air quality.

Light-Absorbing Oligomer Formation in Secondary Organic Aerosol from Reactive Uptake of Isoprene Epoxydiols

2014 ◽  
Vol 48 (20) ◽  
pp. 12012-12021 ◽  
Author(s):  
Ying-Hsuan Lin ◽  
Sri Hapsari Budisulistiorini ◽  
Kevin Chu ◽  
Richard A. Siejack ◽  
Haofei Zhang ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Oligomer Formation

scholarly journals Emissions of terpenoids, benzenoids, and other biogenic gas-phase organic compounds from agricultural crops and their potential implications for air quality

2013 ◽  
Vol 13 (11) ◽  
pp. 28343-28393 ◽  
Author(s):  
D. R. Gentner ◽  
E. Ormeño ◽  
S. Fares ◽  
T. B. Ford ◽  
R. Weber ◽  
...  
Keyword(s):  
Air Quality ◽  
Gas Phase ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
San Joaquin Valley ◽  
Anthropogenic Emissions ◽  
Agricultural Crops ◽  
Substantial Fraction ◽  
Regional Air Quality ◽  
Orange Orchard

Abstract. Agriculture comprises a substantial fraction of land cover in many regions of the world, including California's San Joaquin Valley, which is out of compliance with state and federal standards for tropospheric ozone and particulate matter (PM2.5). Emissions from vegetation and other biogenic and anthropogenic sources react in the atmosphere to produce ozone and secondary organic aerosol, which comprises a substantial fraction of PM2.5. Using data from three measurement campaigns, we examine emissions of reactive gas-phase organic carbon from agricultural crops and their potential to impact regional air quality relative to anthropogenic emissions in California's San Joaquin Valley. Emission rates for a suite of biogenic terpenoid compounds were measured in a greenhouse for 25 representative crops from California in 2008, and ambient measurements of terpenoids and other biogenic compounds in the volatile and intermediate-volatility organic compound range were made over an orange orchard in a rural area of the San Joaquin Valley during two seasons in 2010: summer and spring flowering. When accounting for both emissions of reactive precursors and the deposition of ozone to an orange orchard, the net effect of the orange trees is a net source of ozone in the springtime during flowering, and relatively neutral for most of the summer until the fall when it becomes a sink. Flowering was a major emission event and caused a large increase in emissions including a suite of compounds that had not been measured in the atmosphere before. Such biogenic emission events need to be better parameterized in models as they have significant potential to impact regional air quality since emissions increase by an order of magnitude. In regions like the San Joaquin Valley, the mass of biogenic emissions from agricultural crops during the summer (without flowering) and the potential ozone and secondary organic aerosol formation from these emissions are on the same order as anthropogenic emissions from motor vehicles and must be considered in air quality models and secondary pollution control strategies.

scholarly journals High formation of secondary organic aerosol from the photo-oxidation of toluene

2009 ◽  
Vol 9 (1) ◽  
pp. 693-733 ◽  
Author(s):  
L. Hildebrandt ◽  
N. M. Donahue ◽  
S. N. Pandis
Keyword(s):  
Air Quality ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Ambient Conditions ◽  
Dynamic Nature ◽  
Experimental Conditions ◽  
Quality Models ◽  
Photo Oxidation ◽  
Aerosol Mass ◽  
Photochemical Aging

Abstract. Toluene and other aromatics have long been viewed as the dominant anthropogenic secondary organic aerosol (SOA) precursors, but the SOA mass yields from toluene reported in previous studies vary widely. Experiments conducted in the Carnegie Mellon University environmental chamber to study SOA formation from the photo-oxidation of toluene show significantly larger SOA production than parameterizations employed in current air-quality models. Aerosol mass yields depend on experimental conditions: yields are higher under higher UV intensity, under low-NOx conditions and at lower temperatures. The extent of oxidation of the aerosol also varies with experimental conditions, consistent with ongoing, progressive photochemical aging of the toluene SOA. Measurements using a thermodenuder system suggest that the aerosol formed under high- and low-NOx conditions is semi-volatile. These results suggest that SOA formation from toluene depends strongly on ambient conditions. An approximate parameterization is proposed for use in air-quality models until a more thorough treatment accounting for the dynamic nature of this system becomes available.

scholarly journals Simulating secondary organic aerosol in a regional air quality model using the statistical oxidation model – Part 2: Assessing the influence of vapor wall losses

2015 ◽  
Vol 15 (21) ◽  
pp. 30081-30126 ◽  
Author(s):  
C. D. Cappa ◽  
S. H. Jathar ◽  
M. J. Kleeman ◽  
K. S. Docherty ◽  
J. L. Jimenez ◽  
...  
Keyword(s):  
Air Quality ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Air Quality Model ◽  
Quality Model ◽  
Wall Losses ◽  
Regional Air Quality ◽  
High Vapor ◽  
Wall Loss ◽  
Oxidation Model

Abstract. The influence of losses of organic vapors to chamber walls during secondary organic aerosol (SOA) formation experiments has recently been established. Here, the influence of such losses on simulated ambient SOA concentrations and properties is assessed in the UCD/CIT regional air quality model using the statistical oxidation model (SOM) for SOA. The SOM was fit to laboratory chamber data both with and without accounting for vapor wall losses following the approach of Zhang et al. (2014). Two vapor wall loss scenarios are considered when fitting of SOM to chamber data to determine best-fit SOM parameters, one with "low" and one with "high" vapor wall-loss rates to approximately account for the current range of uncertainty in this process. Simulations were run using these different parameterizations (scenarios) for both the southern California/South Coast Air Basin (SoCAB) and the eastern United States (US). Accounting for vapor wall losses leads to substantial increases in the simulated SOA concentrations from VOCs in both domains, by factors of ~ 2–5 for the low and ~ 5–10 for the high scenario. The magnitude of the increase scales approximately inversely with the absolute SOA concentration of the no loss scenario. In SoCAB, the predicted SOA fraction of total OA increases from ~ 0.2 (no) to ~ 0.5 (low) and to ~ 0.7 (high), with the high vapor wall loss simulations providing best general agreement with observations. In the eastern US, the SOA fraction is large in all cases but increases further when vapor wall losses are accounted for. The total OA/ΔCO ratio represents dilution-corrected SOA concentrations. The simulated OA/ΔCO in SoCAB (specifically, at Riverside, CA) is found to increase substantially during the day only for the high vapor wall loss scenario, which is consistent with observations and indicative of photochemical production of SOA. Simulated O : C atomic ratios for both SOA and for total OA increase when vapor wall losses are accounted for, while simulated H : C atomic ratios decrease. The agreement between simulations and observations of both the absolute values and the diurnal profile of the O : C and H : C atomic ratios for total OA was greatly improved when vapor wall-losses were accounted for. Similar improvements would likely not be possible solely through the inclusion of semi/intermediate volatility organic compounds in the simulations. These results overall demonstrate that vapor wall losses in chambers have the potential to exert a large influence on simulated ambient SOA concentrations, and further suggest that accounting for such effects in models can explain a number of different observations and model/measurement discrepancies.

scholarly journals Quantification of secondary organic aerosol in an Australian urban location

2011 ◽  
Vol 8 (2) ◽  
pp. 115 ◽  
Author(s):  
Melita Keywood ◽  
Helen Guyes ◽  
Paul Selleck ◽  
Rob Gillett
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Elemental Carbon ◽  
Secondary Organic Aerosol ◽  
Fine Particulate Matter ◽  
Ambient Air ◽  
Organic Aerosol ◽  
Quality Data ◽  
Combustion Source ◽  
First Time

Environmental contextParticulate matter is detrimental to human health necessitating air quality standards to ensure that populations are not exposed to harmful levels of air pollutants. We quantified, for the first time in an Australian city, secondary organic aerosol produced in the atmosphere by chemical reactions, and show that it constitutes a significant fraction of the fine particulate matter. Secondary organic aerosol should be considered in regulations to control particulate matter and ozone. AbstractThe contribution of secondary organic aerosol (SOA) to particulate mass (PM) in an Australian urban airshed is quantified for the first time in this work. SOA is estimated indirectly using the elemental carbon tracer method. The contribution of primary organic carbon (OC) to PM is determined using ambient air quality data, which is used to indicate photochemical activity and as a tracer for a general vehicular combustion source. In addition, levoglucosan concentrations were used to determine the contribution of wood heater emissions to primary OC. The contribution of bushfire smoke to primary OC emissions was determined from the organic and elemental carbon (OC/EC) ratios measured in bushfire source samples. The median annual SOA concentration determined in this work was 1.1 µg m–3, representing ~13% of PM2.5 median concentrations on an annual basis (assuming a ratio of organic mass (OM) to OC of 1.6). Significantly higher SOA concentrations were determined when bushfire smoke affected the airshed; however, the SOA fraction of PM2.5 was greatest during the autumn and early winter months when the formation of inversions allows build up of particles produced by domestic wood-heater emissions.

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