scholarly journals Wintertime secondary organic aerosol formation in Beijing-Tianjin-Hebei (BTH): Contributions of HONO sources and heterogeneous reactions

2018 ◽  
Author(s):  
Li Xing ◽  
Jiarui Wu ◽  
Miriam Elser ◽  
Shengrui Tong ◽  
Suixin Liu ◽  
...  
Keyword(s):  
Organic Aerosols ◽  
Organic Aerosol ◽  
Heterogeneous Reactions ◽  
Weather Research And Forecasting ◽  
Aerosol Formation ◽  
Near Surface ◽  
Formation Pathway ◽  
Residential Living ◽  
The Impact ◽  
Haze Days

Abstract. Organic aerosol (OA) concentrations are simulated over the Beijing-Tianjin-Hebei (BTH) region from 9 to 26 January, 2014 using the Weather Research and Forecasting model coupled with chemistry (WRF-CHEM), with the goal of examining the impact of heterogeneous HONO sources on SOA formation and the SOA formation from different pathways during wintertime haze days. The model generally performs well in simulating air pollutants and organic aerosols against measurements in BTH. Model results show that heterogeneous HONO sources substantially enhance the near-surface SOA formation, increasing regional average near-surface SOA concentration by about 46.3 % during the episode. Oxidation and partitioning of primary organic aerosols treated as semi-volatile dominate the SOA formation, contributing 58.9 % of the near-surface SOA mass in BTH. Irreversible uptake of glyoxal and methylglyoxal on aerosol surfaces constitutes the second most important SOA formation pathway during the episode, with SOA contribution increasing from 8.5 % in non-haze conditions to 30.2 % in haze conditions. Additionally, direct emissions of glyoxal and methylglyoxal from residential living sources contribute about 25.5 % to the total SOA mass on average in BTH. Our study highlights the importance of heterogeneous HONO sources and primary residential emissions of glyoxal and methylglyoxal to SOA formation in winter over BTH.

scholarly journals Wintertime secondary organic aerosol formation in Beijing–Tianjin–Hebei (BTH): contributions of HONO sources and heterogeneous reactions

2019 ◽  
Vol 19 (4) ◽  
pp. 2343-2359 ◽  
Author(s):  
Li Xing ◽  
Jiarui Wu ◽  
Miriam Elser ◽  
Shengrui Tong ◽  
Suixin Liu ◽  
...  
Keyword(s):  
Organic Aerosols ◽  
Organic Aerosol ◽  
Heterogeneous Reactions ◽  
Weather Research And Forecasting ◽  
Aerosol Formation ◽  
Near Surface ◽  
Formation Pathway ◽  
The Impact ◽  
Haze Days ◽  
Bth Region

Abstract. Organic aerosol (OA) concentrations are simulated over the Beijing–Tianjin–Hebei (BTH) region from 9 to 26 January 2014 using the Weather Research and Forecasting model coupled with chemistry (WRF-CHEM), with the goal of examining the impact of heterogeneous HONO sources on SOA formation and SOA formation from different pathways during wintertime haze days. The model generally shows good performance with respect to simulating air pollutants and organic aerosols against measurements in BTH. Model results show that heterogeneous HONO sources substantially enhance near-surface SOA formation, increasing the regional average near-surface SOA concentration by about 46.3 % during the episode. Oxidation and partitioning of primary organic aerosols treated as semi-volatile dominate SOA formation, contributing 58.9 % of the near-surface SOA mass in BTH. Irreversible uptake of glyoxal and methylglyoxal on aerosol surfaces constitutes the second most important SOA formation pathway during the episode, with the SOA contribution increasing from 8.5 % under non-haze conditions to 30.2 % under haze conditions. Additionally, direct emissions of glyoxal and methylglyoxal from residential sources contribute about 25.5 % of the total SOA mass on average in BTH. Our study highlights the importance of heterogeneous HONO sources and primary residential emissions of glyoxal and methylglyoxal to SOA formation over the BTH region in winter.

scholarly journals Environmentally dependent dust chemistry of a super Asian dust storm in March 2010: observation and simulation

2017 ◽  
Author(s):  
Qiongzhen Wang ◽  
Xinyi Dong ◽  
Joshua S. Fu ◽  
Jian Xu ◽  
Congrui Deng ◽  
...  
Keyword(s):  
Air Quality ◽  
Dust Storm ◽  
Model Simulation ◽  
Eastern China ◽  
Heterogeneous Reactions ◽  
Anthropogenic Emissions ◽  
Aerosol Formation ◽  
Air Quality Model ◽  
Near Surface ◽  
The Impact

Abstract. Near surface and vertical in situ measurements of atmospheric aerosols were conducted in Shanghai during March 19–27, 2010 to explore the transport and chemical evolution of dust aerosols in a super dust storm. An air quality model with optimized physical dust emission scheme and newly implemented dust chemistry was utilized to study the impact of dust chemistry on regional air quality. Two discontinuous dust periods were observed with one travelling over Northern China (DS1) and the other passing over the coastal regions of Eastern China (DS2). Stronger mixing extents between dust and anthropogenic emissions were found in DS2, reflecting by the higher SO2/PM10 and NO2/PM10 ratios as well as typical pollution elemental species such as As, Cd, Pb, and Zn. As a result, the concentrations of SO42− and NO3− and the ratio of Ca2+/Ca were more elevated in DS2 than in DS1 but opposite for the [NH4+]/[SO42−+NO3−] ratio, suggesting the heterogeneous reactions between calcites and acid gases were significantly promoted in DS2 due to the higher level of relative humidity and gaseous pollution precursors. Lidar observation showed a columnar effect on the vertical structure of aerosol optical properties in DS1 that dust dominantly accounted for ~80–90 % of the total aerosol extinction from near the ground to ~700 m. In contrast, the dust plumes in DS2 were refrained within lower altitudes while the extinction from spheric particles exhibited maximum at a high altitude of ~800 m. The model simulation reproduced relatively consistent results with observations that strong impacts of dust heterogeneous reactions on secondary aerosol formation occurred in areas where the anthropogenic emissions were intensive. Compared to the sulfate simulation, the nitrate formation on dust is suggested to be improved in the future modeling efforts.

scholarly journals Environmentally dependent dust chemistry of a super Asian dust storm in March 2010: observation and simulation

2018 ◽  
Vol 18 (5) ◽  
pp. 3505-3521 ◽  
Author(s):  
Qiongzhen Wang ◽  
Xinyi Dong ◽  
Joshua S. Fu ◽  
Jian Xu ◽  
Congrui Deng ◽  
...  
Keyword(s):  
Air Quality ◽  
Dust Storm ◽  
Eastern China ◽  
Heterogeneous Reactions ◽  
Spherical Particles ◽  
Dust Particles ◽  
Anthropogenic Emissions ◽  
Aerosol Formation ◽  
Near Surface ◽  
The Impact

Abstract. Near-surface and vertical in situ measurements of atmospheric particles were conducted in Shanghai during 19–23 March 2010 to explore the transport and chemical evolution of dust particles in a super dust storm. An air quality model with optimized physical dust emission scheme and newly implemented dust chemistry was utilized to study the impact of dust chemistry on regional air quality. Two discontinuous dust periods were observed with one traveling over northern China (DS1) and the other passing over the coastal regions of eastern China (DS2). Stronger mixing extents between dust and anthropogenic emissions were found in DS2, reflected by the higher SO2 ∕ PM10 and NO2 ∕ PM10 ratios as well as typical pollution elemental species such as As, Cd, Pb, and Zn. As a result, the concentrations of SO42- and NO3- and the ratio of Ca2+ ∕ Ca were more elevated in DS2 than in DS1 but opposite for the [NH4+] ∕ [SO42-+NO3-] ratio, suggesting the heterogeneous reactions between calcites and acid gases were significantly promoted in DS2 due to the higher level of relative humidity and gaseous pollution precursors. Lidar observation showed a columnar effect on the vertical structure of particle optical properties in DS1 that dust dominantly accounted for ∼ 80–90 % of the total particle extinction from near the ground to ∼ 700 m. In contrast, the dust plumes in DS2 were restrained within lower altitudes while the extinction from spherical particles exhibited a maximum at a high altitude of ∼ 800 m. The model simulation reproduced relatively consistent results with observations that strong impacts of dust heterogeneous reactions on secondary aerosol formation occurred in areas where the anthropogenic emissions were intensive. Compared to the sulfate simulation, the nitrate formation on dust is suggested to be improved in the future modeling efforts.

scholarly journals Sensitivity of biogenic volatile organic compounds to land surface parameterizations and vegetation distributions in California

2016 ◽  
Vol 9 (5) ◽  
pp. 1959-1976 ◽  
Author(s):  
Chun Zhao ◽  
Maoyi Huang ◽  
Jerome D. Fast ◽  
Larry K. Berg ◽  
Yun Qian ◽  
...  
Keyword(s):  
Air Quality ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Land Surface ◽  
Aerosol Formation ◽  
Biogenic Volatile Organic Compounds ◽  
Vegetation Map ◽  
Near Surface ◽  
Volatile Organic ◽  
The Impact

Abstract. Current climate models still have large uncertainties in estimating biogenic trace gases, which can significantly affect atmospheric chemistry and secondary aerosol formation that ultimately influences air quality and aerosol radiative forcing. These uncertainties result from many factors, including uncertainties in land surface processes and specification of vegetation types, both of which can affect the simulated near-surface fluxes of biogenic volatile organic compounds (BVOCs). In this study, the latest version of Model of Emissions of Gases and Aerosols from Nature (MEGAN v2.1) is coupled within the land surface scheme CLM4 (Community Land Model version 4.0) in the Weather Research and Forecasting model with chemistry (WRF-Chem). In this implementation, MEGAN v2.1 shares a consistent vegetation map with CLM4 for estimating BVOC emissions. This is unlike MEGAN v2.0 in the public version of WRF-Chem that uses a stand-alone vegetation map that differs from what is used by land surface schemes. This improved modeling framework is used to investigate the impact of two land surface schemes, CLM4 and Noah, on BVOCs and examine the sensitivity of BVOCs to vegetation distributions in California. The measurements collected during the Carbonaceous Aerosol and Radiative Effects Study (CARES) and the California Nexus of Air Quality and Climate Experiment (CalNex) conducted in June of 2010 provided an opportunity to evaluate the simulated BVOCs. Sensitivity experiments show that land surface schemes do influence the simulated BVOCs, but the impact is much smaller than that of vegetation distributions. This study indicates that more effort is needed to obtain the most appropriate and accurate land cover data sets for climate and air quality models in terms of simulating BVOCs, oxidant chemistry and, consequently, secondary organic aerosol formation.

scholarly journals 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

2020 ◽  
Vol 20 (10) ◽  
pp. 5995-6014 ◽  
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.

scholarly journals Impact of molecular structure on secondary organic aerosol formation from aromatic hydrocarbon photooxidation under low NO<sub><i>x</i></sub> conditions

2016 ◽  
Author(s):  
L. Li ◽  
P. Tang ◽  
S. Nakao ◽  
D. R. Cocker III
Keyword(s):  
Molecular Structure ◽  
Chemical Composition ◽  
Aromatic Hydrocarbon ◽  
Chain Length ◽  
Aromatic Hydrocarbons ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Ortho Position ◽  
Aerosol Formation ◽  
The Impact

Abstract. The molecular structure of volatile organic compounds (VOC) determines their oxidation pathway, directly impacting secondary organic aerosol (SOA) formation. This study comprehensively investigates the impact of molecular structure on SOA formation from the photooxidation of twelve different eight to nine carbon aromatic hydrocarbons under low NOx conditions. The effects of the alkyl substitute number, location, carbon chain length and branching structure on the photooxidation of aromatic hydrocarbons are demonstrated by analyzing SOA yield, chemical composition and physical properties. Aromatic hydrocarbons, categorized into five groups, show a yield order of ortho (o-xylene and o-ethyltoluene) > one substitute (ethylbenzene, propylbenzene and isopropylbenzene) > meta (m-xylene and m-ethyltoluene) > three substitute (trimethylbenzenes) > para (p-xylene and p-ethyltoluene). SOA yields of aromatic hydrocarbon photooxidation do not monotonically decrease when increasing alkyl substitute number. The ortho position promotes SOA formation while the para position suppresses aromatic oxidation and SOA formation. Observed SOA chemical composition and volatility confirm that higher yield is associated with further oxidation. SOA chemical composition also suggests that aromatic oxidation increases with increasing alkyl substitute chain length and branching structure. Further, carbon dilution theory developed by Li et al. (2015a) is extended in this study to serve as a standard method to determine the extent of oxidation of an alkyl substituted aromatic hydrocarbon.

scholarly journals Modeling organic aerosols in a megacity: comparison of simple and complex representations of the volatility basis set approach

2010 ◽  
Vol 10 (12) ◽  
pp. 30205-30277 ◽  
Author(s):  
M. Shrivastava ◽  
J. Fast ◽  
R. Easter ◽  
W. I. Gustafson ◽  
R. A. Zaveri ◽  
...  
Keyword(s):  
Gas Phase ◽  
Secondary Organic Aerosol ◽  
Computational Cost ◽  
Organic Aerosols ◽  
Field Measurements ◽  
Organic Aerosol ◽  
Basis Set ◽  
Aerosol Formation ◽  
Secondary Organic Aerosol Formation ◽  
The City

Abstract. The Weather Research and Forecasting model coupled with chemistry (WRF-Chem) is modified to include a volatility basis set (VBS) treatment of secondary organic aerosol formation. The VBS approach, coupled with SAPRC-99 gas-phase chemistry mechanism, is used to model gas-particle partitioning and multiple generations of gas-phase oxidation of organic vapors. In addition to the detailed 9-species VBS, a simplified mechanism using 2 volatility species (2-species VBS) is developed and tested for similarity to the 9-species VBS in terms of both mass and oxygen-to-carbon ratios of organic aerosols in the atmosphere. WRF-Chem results are evaluated against field measurements of organic aerosols collected during the MILAGRO 2006 campaign in the vicinity of Mexico City. The simplified 2-species mechanism reduces the computational cost by a factor of 2 as compared to 9-species VBS. Both ground site and aircraft measurements suggest that the 9-species and 2-species VBS predictions of total organic aerosol mass as well as individual organic aerosol components including primary, secondary, and biomass burning are comparable in magnitude. In addition, oxygen-to-carbon ratio predictions from both approaches agree within 25%, providing evidence that the 2-species VBS is well suited to represent the complex evolution of organic aerosols. Model sensitivity to amount of anthropogenic semi-volatile and intermediate volatility (S/IVOC) precursor emissions is also examined by doubling the default emissions. Both the emission cases significantly under-predict primary organic aerosols in the city center and along aircraft flight transects. Secondary organic aerosols are predicted reasonably well along flight tracks surrounding the city, but are consistently over-predicted downwind of the city. Also, oxygen-to-carbon ratio predictions are significantly improved compared to prior studies by adding 15% oxygen mass per generation of oxidation; however, all modeling cases still under-predict these ratios downwind as compared to measurements, suggesting a need to further improve chemistry parameterizations of secondary organic aerosol formation.

scholarly journals Assessing the impact of anthropogenic pollution on isoprene-derived secondary organic aerosol formation in PM<sub>2.5</sub> collected from the Birmingham, Alabama ground site during the 2013 Southern Oxidant and Aerosol Study

2016 ◽  
Author(s):  
W. Rattanavaraha ◽  
K. Chu ◽  
S. H. Budisulistiorini ◽  
M. Riva ◽  
Y.-H. Lin ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Organic Aerosol ◽  
Anthropogenic Pollution ◽  
Organic Aerosol ◽  
Limiting Factor ◽  
Ionization Mass ◽  
Aerosol Formation ◽  
Anthropogenic Pollutants ◽  
Aerosol Acidity ◽  
The Impact

Abstract. In the southeastern U.S., substantial emissions of isoprene from deciduous trees undergo atmospheric oxidation to form secondary organic aerosol (SOA) that contributes to fine particulate matter (PM2.5). Laboratory studies have revealed that anthropogenic pollutants, such as sulfur dioxide (SO2), oxides of nitrogen (NOx), and aerosol acidity, can enhance SOA formation from the hydroxyl radical (OH)-initiated oxidation of isoprene; however, the mechanisms by which specific pollutants enhance isoprene SOA in ambient PM2.5 remain unclear. As one aspect of an investigation to examine how anthropogenic pollutants influence isoprene-derived SOA formation, high-volume PM2.5 filter samples were collected at the Birmingham, Alabama (BHM) ground site during the 2013 Southern Oxidant and Aerosol Study (SOAS). Sample extracts were analyzed by gas chromatography/electron ionization-mass spectrometry (GC/EI-MS) with prior trimethylsilylation and ultra performance liquid chromatography coupled to an electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR QTOFMS) to identify known isoprene SOA tracers. Tracers quantified using both surrogate and authentic standards were compared with collocated gas- and particle-phase data as well as meteorological data provided by the Southeastern Aerosol Research and Characterization (SEARCH) network to assess the impact of anthropogenic pollution on isoprene-derived SOA formation. Results of this study reveal that isoprene-derived SOA tracers contribute a substantial mass fraction of organic matter (OM) (~7 to ~20%). Isoprene-derived SOA tracers correlated with sulfate (SO42-) (r2 = 0.34, n = 117), but not with NOx. Moderate correlation between methacrylic acid epoxide and hydroxymethyl-methyl-α-lactone (MAE/HMML)-derived SOA tracers and nitrate radical production (P[NO3]) (r2 = 0.57, n = 40) were observed during nighttime, suggesting a potential role of NO3 radical in forming this SOA type. However, the nighttime correlation of these tracers with nitrogen dioxide (NO2) (r2 = 0.26, n = 40) was weaker. Ozone (O3) correlated strongly with MAE/HMML-derived tracers (r2 = 0.72, n = 30) and moderately with 2-methyltetrols (r2 = 0.34, n = 15) during daytime only, suggesting that a fraction of SOA formation could occur from isoprene ozonolysis in urban areas. No correlation was observed between aerosol pH and isoprene-derived SOA. Lack of correlation between aerosol acidity and isoprene-derived SOA indicates that acidity is not a limiting factor for isoprene SOA formation at the BHM site as aerosols were acidic enough to promote multiphase chemistry of isoprene-derived epoxides throughout the duration of the study. All in all, these results confirm the reports that anthropogenic pollutants enhance isoprene-derived SOA formation.

Sign in / Sign up

Export Citation Format

Share Document