Source Attribution of Submicron Organic Aerosols during Wintertime Inversions by Advanced Factor Analysis of Aerosol Mass Spectra

2008 ◽  
Vol 42 (1) ◽  
pp. 214-220 ◽  
Author(s):  
Valentin A. Lanz ◽  
M. Rami Alfarra ◽  
Urs Baltensperger ◽  
Brigitte Buchmann ◽  
Christoph Hueglin ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Mass Spectra ◽  
Organic Aerosols ◽  
Source Attribution ◽  
Aerosol Mass

scholarly journals Understanding atmospheric organic aerosols via factor analysis of aerosol mass spectrometry: a review

2011 ◽  
Vol 401 (10) ◽  
pp. 3045-3067 ◽  
Author(s):  
Qi Zhang ◽  
Jose L. Jimenez ◽  
Manjula R. Canagaratna ◽  
Ingrid M. Ulbrich ◽  
Nga L. Ng ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Factor Analysis ◽  
Organic Aerosols ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry

scholarly journals Hydrocarbon-like and oxygenated organic aerosols in Pittsburgh: insights into sources and processes of organic aerosols

2005 ◽  
Vol 5 (5) ◽  
pp. 8421-8471 ◽  
Author(s):  
Q. Zhang ◽  
D. R. Worsnop ◽  
M. R. Canagaratna ◽  
J.-L. Jimenez
Keyword(s):  
Organic Carbon ◽  
Mass Spectra ◽  
Organic Aerosols ◽  
Organic Aerosol ◽  
Particle Formation ◽  
Total Carbon ◽  
New Particle Formation ◽  
Aerosol Mass ◽  
Diurnal Profile ◽  
Mass Concentrations

Abstract. A recently developed algorithm (Zhang et al., 2005) has been applied to deconvolve the mass spectra of organic aerosols acquired with the Aerosol Mass Spectrometer (AMS) in Pittsburgh during September 2002. The results are used here to characterize the mass concentrations, size distributions, and mass spectra of hydrocarbon-like and oxygenated organic aerosol (HOA and OOA, respectively). HOA accounts for 34% of the measured organic aerosol mass and OOA accounts for 66%. The mass concentrations of HOA demonstrate a prominent diurnal profile that peaks in the morning during the rush hour and decreases with the rise of the boundary layer. The diurnal profile of OOA is relatively flat and resembles those of SO42− and NH4+. The size distribution of HOA shows a distinct ultrafine mode that is commonly associated with fresh emissions while OOA is generally concentrated in the accumulation mode and appears to be mostly internally mixed with the inorganic ions, such as SO42− and NH4+. These observations suggest that HOA is likely primary aerosol from local, combustion-related emissions and that OOA is secondary organic aerosol (SOA) influenced by regional contributions. There is strong evidence of the direct correspondence of OOA to SOA during an intense new particle formation and growth event, when condensational growth of OOA was observed. The mass spectrum of OOA of this new particle formation event is very similar to the OOA spectrum of the entire study, which strongly suggests that most OOA during this study is SOA. O3 appears to be a poor indicator for SOA concentration while SO42− is a relatively good surrogate for this dataset. Since the diurnal averages of HOA tightly track those of CO during day time, oxidation/aging of HOA appears to be very small on the time scale of several hours. Based on extracted mass spectra and the likely elemental compositions of major m/z's, the organic mass to organic carbon ratios (OM:OC) of HOA and OOA are estimated at 1.2 and 2.2 μg/μg C, respectively, leading to an average OM:OC ratio of 1.8 for submicron OA in Pittsburgh during September. The C:O ratio of OOA is estimated at 1:0.8. The carbon contents in HOA and OOA calculated accordingly correlate well to primary and secondary organic carbon, respectively, estimated by the OC/EC tracer technique (assuming POC-to-EC ratio=1). In addition, the total carbon concentrations calculated from the AMS data agree well with those measured by the Sunset Laboratory Carbon analyzer (r2=0.87; slope=1.01±0.11).

scholarly journals Hydrocarbon-like and oxygenated organic aerosols in Pittsburgh: insights into sources and processes of organic aerosols

2005 ◽  
Vol 5 (12) ◽  
pp. 3289-3311 ◽  
Author(s):  
Q. Zhang ◽  
D. R. Worsnop ◽  
M. R. Canagaratna ◽  
J. L. Jimenez
Keyword(s):  
Organic Carbon ◽  
Mass Spectra ◽  
Organic Aerosols ◽  
Organic Aerosol ◽  
Total Carbon ◽  
Direct Estimate ◽  
Entire Study ◽  
Aerosol Mass ◽  
Diurnal Profile ◽  
Mass Concentrations

Abstract. A recently developed algorithm (Zhang et al., 2005) has been applied to deconvolve the mass spectra of organic aerosols acquired with the Aerosol Mass Spectrometer (AMS) in Pittsburgh during September 2002. The results are used here to characterize the mass concentrations, size distributions, and mass spectra of hydrocarbon-like and oxygenated organic aerosol (HOA and OOA, respectively). HOA accounts for 34% of the measured organic aerosol mass and OOA accounts for 66%. The mass concentrations of HOA demonstrate a prominent diurnal profile that peaks in the morning during the rush hour and decreases with the rise of the boundary layer. The diurnal profile of OOA is relatively flat and resembles those of SO42− and NH4+. The size distribution of HOA shows a distinct ultrafine mode that is commonly associated with fresh emissions while OOA is generally concentrated in the accumulation mode and appears to be mostly internally mixed with the inorganic ions, such as SO42− and NH4+. These observations suggest that HOA is likely primary aerosol from local, combustion-related emissions and that OOA is secondary organic aerosol (SOA) influenced by regional contributions. There is strong evidence of the direct correspondence of OOA to SOA during an intense new particle formation and growth event, when condensational growth of OOA was observed. The fact that the OOA mass spectrum from this event is very similar to that from the entire study suggests that the majority of OOA in Pittsburgh is likely SOA. O3 appears to be a poor indicator for OOA concentration while SO42− is a relatively good surrogate for this dataset. Since the diurnal averages of HOA track those of CO during day time, oxidation/aging of HOA appears to be very small on the time scale of several hours. Based on extracted mass spectra and the likely elemental compositions of major m/z's, the organic mass to organic carbon ratios (OM:OC) of HOA and OOA are estimated at 1.2 and 2.2 μg/μgC, respectively, leading to an average OM:OC ratio of 1.8 for submicron OA in Pittsburgh during September. The C:O ratio of OOA is estimated at 1:0.8. The carbon contents in HOA and OOA estimated accordingly correlate well to primary and secondary organic carbon, respectively, estimated by the OC/EC tracer technique (assuming POC-to-EC ratio=1). In addition, the total carbon concentrations estimated from the AMS data agree well with those measured by the Sunset Laboratory Carbon analyzer (r2=0.87; slope=1.01±0.11). Our results represent the first direct estimate of the OM:OC ratio from highly time-resolved chemical composition measurements.

Online analysis of secondary organic aerosols from OH-initiated photooxidation and ozonolysis of α-pinene, β-pinene, Δ3-carene and d-limonene by thermal desorption–photoionisation aerosol mass spectrometry

2017 ◽  
Vol 14 (2) ◽  
pp. 75 ◽  
Author(s):  
Wenzheng Fang ◽  
Lei Gong ◽  
Liusi Sheng
Keyword(s):  
Mass Spectrometry ◽  
Thermal Desorption ◽  
Mass Spectra ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Online Analysis ◽  
Aerosol Mass ◽  
Aerosol Mass Spectrometry

Environmental contextSecondary organic aerosol, formed by oxidation of volatile precursors such as monoterpenes, is a major contributor to the total atmospheric organic aerosol. We focus on the online mass spectrometric analysis of the aerosol generated by oxidation products of four major monoterpenes in an environmental chamber. Numerous important monoterpene oxidation products were clearly observed and provided a direct comparison of the formation of biogenic secondary organic aerosols. AbstractWe present here thermal desorption–tunable vacuum ultraviolet time-of-flight photoionisation aerosol mass spectrometry (TD-VUV-TOF-PIAMS) for online analysis of biogenic secondary organic aerosols (BSOAs) formed from OH-initiated photooxidation and dark ozonolysis of α-pinene, β-pinene, Δ3-carene and d-limonene in smog chamber experiments. The ‘soft’ ionisation at near-threshold photon energies (≤10.5eV) used in this study permits direct measurement of the fairly clean mass spectra, facilitating molecular identification. The online BSOA mass spectra compared well with previous offline measurements and most of the important monoterpene oxidation products were clearly found in the online mass spectra. Oxidation products such as monoterpene-derived acids (e.g. pinic acid, pinonic acid, 3-caronic acid, limononic acid, limonalic acid), ketones (e.g. norpinone, limonaketone), aldehydes (e.g. caronaldehyde, norcaronaldehyde, limononaldehyde) and multifunctional organics (e.g. hydroxypinonaldehydes, hydroxy-3-caronic aldehydes, hydroxylimononic acid) were tentatively identified. The online TD-VUV-TOF-PIAMS mass spectra showed that the OH-initiated photooxidation and ozonolysis of the same monoterpenes produced some similar BSOA products; for example, 3-caric acid, 3-caronic acid, 3-norcaronic acid, 3-norcaralic acid, caronaldehyde and norcaronaldehyde were observed in both photooxidation and ozonolysis of Δ3-carene. However, they could be formed through different pathways. Some of the same products and isomers (e.g. 10-oxopinonic acid, pinonic acid, norpinic acid, hydroxyl pinonaldehyde, norpinonic acid, norpinone) were formed during the photooxidation and ozonolysis of α-pinene and β-pinene. However, several different BSOA products were generated in these photooxidation and ozonolysis reactions due to their different parent structures. The OH–monoterpene reaction generated higher-molecular-weight products than O3–monoterpene owing to multiple OH additions to the unsaturated carbon bond. The online observation of key BSOA products provided a direct comparison of BSOA formation among different monoterpenes and insights into the formation pathways in the OH-initiated photooxidation and ozonolysis of monoterpenes.

scholarly journals Characterization of high-resolution aerosol mass spectra of primary organic aerosol emissions from Chinese cooking and biomass burning

2010 ◽  
Vol 10 (9) ◽  
pp. 21237-21257 ◽  
Author(s):  
L.-Y. He ◽  
Y. Lin ◽  
X.-F. Huang ◽  
S. Guo ◽  
L. Xue ◽  
...  
Keyword(s):  
Factor Analysis ◽  
High Resolution ◽  
Biomass Burning ◽  
Mass Spectra ◽  
Organic Aerosol ◽  
Primary Sources ◽  
High Time Resolution ◽  
High Similarity ◽  
Aerosol Mass ◽  
Chinese Cooking

Abstract. Aerosol Mass Spectrometer (AMS) has proved to be a powerful tool to measure submicron particulate composition with high time resolution. Factor analysis of mass spectra (MS) collected worldwide by AMS demonstrates that submicron organic aerosol (OA) is usually composed of several major components, such as oxygenated (OOA), hydrocarbon-like (HOA), biomass burning (BBOA), and other primary OA. In order to help interpretation of component MS from factor analysis of ambient OA datasets, AMS measurement of different primary sources is required for comparison. Such work, however, has been very scarce in the literature, especially for high resolution MS (HR-MS) measurement, which performs improved characterization by separating the ions of different elemental compositions at each m/z in comparison with unit mass resolution MS (UMR-MS) measurement. In this study, primary emissions from four types of Chinese cooking (CC) and six types of biomass burning (BB) were simulated systemically and measured using an Aerodyne High-Resolution Time-of-Flight AMS (HR-ToF-AMS). The MS of the CC emissions show high similarity with m/z 41 and m/z 55 being the highest signals; the MS of the BB emissions also show high similarity with m/z 29 and m/z 43 being the highest signals. The MS difference between the CC and BB emissions is much bigger than that between different CC (or BB) types, especially for the HR-MS. The O/C ratio of OA ranges from 0.08 to 0.13 for the CC emissions while from 0.18 to 0.26 for the BB emissions. The ions of m/z 43, m/z 44, m/z 57, and m/z 60, usually used as tracer ions in AMS measurement, were examined for their HR-MS characteristics in the CC and BB emissions. Moreover, the MS of the CC and BB emissions are also used to compare with component MS from factor analysis of ambient OA datasets observed in China, as well as with other AMS measurements of primary sources in the literature. The MS signatures of cooking and biomass burning emissions revealed in this study can be used as important reference in factor analysis of ambient OA datasets, especially for the relevant studies in East Asia.

scholarly journals Characterization of high-resolution aerosol mass spectra of primary organic aerosol emissions from Chinese cooking and biomass burning

2010 ◽  
Vol 10 (23) ◽  
pp. 11535-11543 ◽  
Author(s):  
L.-Y. He ◽  
Y. Lin ◽  
X.-F. Huang ◽  
S. Guo ◽  
L. Xue ◽  
...  
Keyword(s):  
Factor Analysis ◽  
High Resolution ◽  
Biomass Burning ◽  
Mass Spectra ◽  
Organic Aerosol ◽  
Primary Sources ◽  
High Time Resolution ◽  
High Similarity ◽  
Aerosol Mass ◽  
Chinese Cooking

Abstract. Aerosol mass spectrometry has proved to be a powerful tool to measure submicron particulate composition with high time resolution. Factor analysis of mass spectra (MS) collected worldwide by aerosol mass spectrometer (AMS) demonstrates that submicron organic aerosol (OA) is usually composed of several major components, such as oxygenated (OOA), hydrocarbon-like (HOA), biomass burning (BBOA), and other primary OA. In order to help interpretation of component MS from factor analysis of ambient OA datasets, AMS measurements of different primary sources is required for comparison. Such work, however, has been very scarce in the literature, especially for high resolution MS (HR-MS) measurements, which performs improved characterization by separating the ions of different elemental composition at each m/z in comparison with unit mass resolution MS (UMR-MS) measurements. In this study, primary emissions from four types of Chinese cooking (CC) and six types of biomass burning (BB) were simulated systematically and measured using an Aerodyne High-Resolution Time-of-Flight AMS (HR-ToF-AMS). The MS of the CC emissions show high similarity, with m/z 41 and m/z 55 being the highest signals; the MS of the BB emissions also show high similarity, with m/z 29 and m/z 43 being the highest signals. The MS difference between the CC and BB emissions is much bigger than that between different CC (or BB) types, especially for the HR-MS. The O/C ratio of OA ranges from 0.08 to 0.13 for the CC emissions and from 0.18 to 0.26 for the BB emissions. The UMR ions of m/z 43, m/z 44, m/z 57, and m/z 60, usually used as tracers in AMS measurements, were examined for their HR-MS characteristics in the CC and BB emissions. In addition, the MS of the CC and BB emissions are also compared with component MS from factor analysis of ambient OA datasets observed in China, as well as with other AMS measurements of primary sources in the literature. The MS signatures of cooking and biomass burning emissions revealed in this study can be used as important reference for factor analysis of ambient OA datasets, especially for the relevant studies in East Asia.

scholarly journals Aerosol chemical and optical properties over the Paris area within ESQUIF project

2006 ◽  
Vol 6 (11) ◽  
pp. 3257-3280 ◽  
Author(s):  
A. Hodzic ◽  
R. Vautard ◽  
P. Chazette ◽  
L. Menut ◽  
B. Bessagnet
Keyword(s):  
Optical Properties ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols ◽  
Dust Particles ◽  
Aerosol Size Distribution ◽  
Aerosol Composition ◽  
Aerosol Mass ◽  
Coarse Mode ◽  
Paris Area ◽  
Flight Trajectories

Abstract. Aerosol chemical and optical properties are extensively investigated for the first time over the Paris Basin in July 2000 within the ESQUIF project. The measurement campaign offers an exceptional framework to evaluate the performances of the chemistry-transport model CHIMERE in simulating concentrations of gaseous and aerosol pollutants, as well as the aerosol-size distribution and composition in polluted urban environments against ground-based and airborne measurements. A detailed comparison of measured and simulated variables during the second half of July with particular focus on 19 and 31 pollution episodes reveals an overall good agreement for gas-species and aerosol components both at the ground level and along flight trajectories, and the absence of systematic biases in simulated meteorological variables such as wind speed, relative humidity and boundary layer height as computed by the MM5 model. A good consistency in ozone and NO concentrations demonstrates the ability of the model to reproduce the plume structure and location fairly well both on 19 and 31 July, despite an underestimation of the amplitude of ozone concentrations on 31 July. The spatial and vertical aerosol distributions are also examined by comparing simulated and observed lidar vertical profiles along flight trajectories on 31 July and confirm the model capacity to simulate the plume characteristics. The comparison of observed and modeled aerosol components in the southwest suburb of Paris during the second half of July indicates that the aerosol composition is rather correctly reproduced, although the total aerosol mass is underestimated by about 20%. The simulated Parisian aerosol is dominated by primary particulate matter that accounts for anthropogenic and biogenic primary particles (40%), and inorganic aerosol fraction (40%) including nitrate (8%), sulfate (22%) and ammonium (10%). The secondary organic aerosols (SOA) represent 12% of the total aerosol mass, while the mineral dust accounts for 8%. The comparison demonstrates the absence of systematic errors in the simulated sulfate, ammonium and nitrates total concentrations. However, for nitrates the observed partition between fine and coarse mode is not reproduced. In CHIMERE there is a clear lack of coarse-mode nitrates. This calls for additional parameterizations in order to account for the heterogeneous formation of nitrate onto dust particles. Larger discrepancies are obtained for the secondary organic aerosols due to both inconsistencies in the SOA formation processes in the model leading to an underestimation of their mass and large uncertainties in the determination of the measured aerosol organic fraction. The observed mass distribution of aerosols is not well reproduced, although no clear explanation can be given.

scholarly journals Seasonal characteristics of fine particulate matter (PM) based on high-resolution time-of-flight aerosol mass spectrometric (HR-ToF-AMS) measurements at the HKUST Supersite in Hong Kong

2015 ◽  
Vol 15 (1) ◽  
pp. 37-53 ◽  
Author(s):  
Y. J. Li ◽  
B. P. Lee ◽  
L. Su ◽  
J. C. H. Fung ◽  
C.K. Chan
Keyword(s):  
Hong Kong ◽  
Organic Aerosols ◽  
Organic Aerosol ◽  
Resolution Time ◽  
Time Resolved ◽  
Air Mass ◽  
Aerosol Mass ◽  
Seasonal Characteristics ◽  
Autumn And Winter ◽  
Air Mass Origin

Abstract. Atmospheric particulate matter (PM) remains poorly understood due to the lack of comprehensive measurements at high time resolution for tracking its dynamic features and the lack of long-term observation for tracking its seasonal variability. Here, we present highly time-resolved and seasonal compositions and characteristics of non-refractory components in PM with a diameter less than 1 μm (NR-PM1) at a suburban site in Hong Kong. The measurements were made with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) at the Hong Kong University of Science and Technology (HKUST) Air Quality Research Supersite for 4 months, with one in each season of the year. The average NR-PM1 concentration of ~ 15 μg m−3 is higher than those AMS measurements made in South Korea and Japan, but lower than those in North China, the Yangtze River Delta and the nearby Pearl River Delta. The seasonal dependence of the total NR-PM1 monthly averaged concentrations was small, but that of the fractions of the species in NR-PM1 was significant. Site characteristic plays an important role in the relative fractions of species in NR-PM1 and our results are generally consistent with measurements at other non-urban sites in this regard. Detailed analyses were conducted on the AMS data in the aspects of (1) species concentrations, (2) size distributions, (3) degree of oxygenation of organics, and (4) positive matrix factorization (PMF)-resolved organic factors in a seasonal context, as well as with air mass origin from back-trajectory analysis. Sulfate had the highest fraction in NR-PM1 (> 40%), and the surrogates of secondary organic species – semi-volatile oxygenated organic aerosol (SVOOA) and low-volatility oxygenated organic aerosol (LVOOA) – prevailed (~ 80%) in the organic portion of NR-PM1. Local contributions to the organic portion of NR-PM1 at this suburban site was strongly dependent on season. The hydrocarbon-like organic aerosol (HOA) factor related to local traffic emissions contributed > 10% to organic aerosols in spring and summer but only 6–7% in autumn and winter. The cooking organic aerosol (COA) factor contributed > 10% to organic aerosols in winter. With the aid of highly time-resolved data, diurnal patterns of the degree of oxygenation of organic aerosols were used to determine the sources and formation processes of the least understood organic portion of PM. The oxygen-to-carbon atomic ratio (O : C) and average carbon oxidation state OS C) showed little variation in autumn and winter, when the long-range transport of oxidized organics dominated, whereas they peaked in the afternoon in spring and summer, when locally produced secondary organic aerosol prevailed. Air mass origin, in contrast, had a strong influence on both NR-PM1 concentrations and the fractions of species in NR-PM1. The findings of the current study provide a better understanding of the role of air mass origin in the seasonal characteristics of the PM composition and the relative importance of local vs. transported organic aerosols in this region.

scholarly journals Towards a better understanding of the origins, chemical composition and aging of oxygenated organic aerosols: case study of a Mediterranean industrialized environment, Marseille

2013 ◽  
Vol 13 (15) ◽  
pp. 7875-7894 ◽  
Author(s):  
I. El Haddad ◽  
B. D'Anna ◽  
B. Temime-Roussel ◽  
M. Nicolas ◽  
A. Boreave ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Aerosols ◽  
Industrial Emissions ◽  
Aerosol Mass Spectrometer ◽  
Statistical Confidence ◽  
Aerosol Mass ◽  
Novel Approach ◽  
Organic Markers ◽  
The Impact ◽  
First Time

Abstract. As part of the FORMES summer 2008 experiment, an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS) was deployed at an urban background site in Marseille to investigate the sources and aging of organic aerosols (OA). France's second largest city and the largest port in the Mediterranean, Marseille, provides a locale that is influenced by significant urban industrialized emissions and an active photochemistry with very high ozone concentrations. Particle mass spectra were analyzed by positive matrix factorization (PMF2) and the results were in very good agreement with previous apportionments obtained using a chemical mass balance (CMB) approach coupled to organic markers and metals (El Haddad et al., 2011a). AMS/PMF2 was able to identify for the first time, to the best of our knowledge, the organic aerosol emitted by industrial processes. Even with significant industries in the region, industrial OA was estimated to contribute only ~ 5% of the total OA mass. Both source apportionment techniques suggest that oxygenated OA (OOA) constitutes the major fraction, contributing ~ 80% of OA mass. A novel approach combining AMS/PMF2 data with 14C measurements was applied to identify and quantify the fossil and non-fossil precursors of this fraction and to explicitly assess the related uncertainties. Results show with high statistical confidence that, despite extensive urban and industrial emissions, OOA is overwhelmingly non-fossil, formed via the oxidation of biogenic precursors, including monoterpenes. AMS/PMF2 results strongly suggest that the variability observed in the OOA chemical composition is mainly driven in our case by the aerosol photochemical age. This paper presents the impact of photochemistry on the increase of OOA oxygenation levels, formation of humic-like substances (HULIS) and the evolution of α-pinene SOA (secondary OA) components.

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