Sources of Aerosol Acidity at a Suburban Site of Nanjing and Their Associations with Chlorophyll Depletion

2021 ◽  
Author(s):  
Jiaxing Gong ◽  
Miaomiao Tao ◽  
Qingyang Liu ◽  
Chun Ding ◽  
Pingping Li ◽  
...  
Keyword(s):  
Aerosol Acidity ◽  
Suburban Site

ROx Budgets and O3 Formation during Summertime at Xianghe Suburban Site in the North China Plain

2021 ◽  
Author(s):  
Min Xue ◽  
Jianzhong Ma ◽  
Guiqian Tang ◽  
Shengrui Tong ◽  
Bo Hu ◽  
...  
Keyword(s):  
North China Plain ◽  
North China ◽  
The North ◽  
The North China Plain ◽  
Suburban Site

scholarly journals Determining the Role of Acidity, Fate and Formation of IEPOX-Derived SOA in CMAQ

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 707
Author(s):  
Petros Vasilakos ◽  
Yongtao Hu ◽  
Armistead Russell ◽  
Athanasios Nenes
Keyword(s):  
Significant Influence ◽  
Organic Aerosol ◽  
Liquid Water Content ◽  
Anthropogenic Emissions ◽  
So2 Emissions ◽  
Aerosol Acidity ◽  
A Value ◽  
Future Emission ◽  
The Impact

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability of species such as sulfate and nitrate, and through them, aerosol acidity (pH). To elucidate the role that acidity and emissions play in regulating Secondary Organic Aerosol (SOA), we utilize the 2013 Southern Oxidant and Aerosol Study (SOAS) dataset to enhance the extensive mechanism of isoprene epoxydiol (IEPOX)-mediated SOA formation implemented in the Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used to investigate the impact of potential future emission controls on IEPOX OA. We found that the Henry’s law coefficient for IEPOX was the most impactful parameter that controls aqueous isoprene OA products, and a value of 1.9 × 107 M atm−1 provides the best agreement with measurements. Non-volatile cations (NVCs) were found in higher-than-expected quantities in CMAQ and exerted a significant influence on IEPOX OA by reducing its production by as much as 30% when present. Consistent with previous literature, a strong correlation of isoprene OA with sulfate, and little correlation with acidity or liquid water content, was found. Future reductions in SO2 emissions are found to not affect this correlation and generally act to increase the sensitivity of IEPOX OA to sulfate, even in extreme cases.

NO3 and N2O5 chemistry at a suburban site during the EXPLORE-YRD campaign in 2018

2020 ◽  
Vol 224 ◽  
pp. 117180
Author(s):  
Haichao Wang ◽  
Xiaorui Chen ◽  
Keding Lu ◽  
Renzhi Hu ◽  
Zhiyan Li ◽  
...  
Keyword(s):  
Suburban Site

scholarly journals One-Year Characterization and Reactivity of Isoprene and Its Impact on Surface Ozone Formation at A Suburban Site in Guangzhou, China

Atmosphere ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 201 ◽  
Author(s):  
Yu Zou ◽  
Xue Jiao Deng ◽  
Tao Deng ◽  
Chang Qin Yin ◽  
Fei Li
Keyword(s):  
Surface Ozone ◽  
Atmospheric Composition ◽  
Anthropogenic Factors ◽  
Mixing Ratio ◽  
Night Time ◽  
Subtropical Zone ◽  
Guangzhou City ◽  
Mixing Ratios ◽  
One Year ◽  
Suburban Site

Isoprene has a potentially large effect on ozone (O3) formation in the subtropical, highly polluted city of Guangzhou. Online measurements of isoprene in Guangzhou city are scarce; thus, isoprene levels were monitored for one year at the Guangzhou Panyu Atmospheric Composition Station (GPACS), a suburban site in Guangzhou, using an online gas chromatography-flame ionization detector (GC–FID) system to investigate the characterization and reactivity of isoprene and its effect on the O3 peak profile in different seasons. The results showed that the daily average mixing ratios of isoprene at GPACS were 0.40, 2.20, 1.40, and 0.13 mixing ratio by volume (ppbv) in spring, summer, autumn, and winter, respectively. These values were considerably higher than the mixing ratios of isoprene in the numerous other subtropical and temperate cities around the world. Furthermore, isoprene ranked first with regard to O3 formation potential (OFP) and propylene-equivalent mixing ratio among 56 measured non–methane hydrocarbons (NMHCs). The ratios of isoprene to cis-2-butene, an exhaust tracer, were determined to estimate the fractions of biogenic and anthropogenic emissions. The results revealed a much greater contribution from biogenic than anthropogenic factors during the daytime in all four seasons. In addition, night-time isoprene emissions were mostly associated with vehicles in winter, and the residual isoprene that remained after photochemical loss during the daytime also persisted into the night. The high levels of isoprene in summer and autumn may cause the strong and broad peaks of the O3 profile because of its association with the most favorable meteorological conditions (e.g., high temperature and intense solar radiation) and the highest OH mixing ratio, which could affect human health by exposing people to a high O3 mixing ratio for prolonged periods. The lower mixing ratios of isoprene resulted in a weak and sharp peak in the O3 profile in both spring and winter. The high level of isoprene in the subtropical zone could accentuate its large impact on atmospheric oxidant capacity and air quality in Guangzhou city.

scholarly journals Spatial and seasonal variability of PM<sub>2.5</sub> acidity at two Chinese megacities: insights into the formation of secondary inorganic aerosols

2012 ◽  
Vol 12 (3) ◽  
pp. 1377-1395 ◽  
Author(s):  
K. He ◽  
Q. Zhao ◽  
Y. Ma ◽  
F. Duan ◽  
F. Yang ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Temporal Variations ◽  
Early Summer ◽  
Heterogeneous Reactions ◽  
Rural Site ◽  
Urban Site ◽  
Simultaneous Increase ◽  
Northwestern Pacific ◽  
Inorganic Aerosols ◽  
Aerosol Acidity

Abstract. Aerosol acidity is one of the most important parameters influencing atmospheric chemistry and physics. Based on continuous field observations from January 2005 to May 2006 and thermodynamic modeling, we investigated the spatial and seasonal variations in PM2.5 acidity in two megacities in China, Beijing and Chongqing. Spatially, PM2.5 was generally more acidic in Chongqing than in Beijing, but a reverse spatial pattern was found within the two cities, with more acidic PM2.5 at the urban site in Beijing whereas the rural site in Chongqing. Ionic compositions of PM2.5 revealed that it was the higher concentrations of NO3− at the urban site in Beijing and the lower concentrations of Ca2+ within the rural site in Chongqing that made their PM2.5 more acidic. Temporally, PM2.5 was more acidic in summer and fall than in winter, while in the spring of 2006, the acidity of PM2.5 was higher in Beijing but lower in Chongqing than that in 2005. These were attributed to the more efficient formation of nitrate relative to sulfate as a result of the influence of Asian desert dust in 2006 in Beijing and the greater wet deposition of ammonium compared to sulfate and nitrate in 2005 in Chongqing. Furthermore, simultaneous increase of PM2.5 acidity was observed from spring to early summer of 2005 in both cities. This synoptic-scale evolution of PM2.5 acidity was accompanied by the changes in air masses origins, which were influenced by the movements of a subtropical high over the northwestern Pacific in early summer. Finally, the correlations between [NO3−]/[SO42−] and [NH4+]/[SO42−] suggests that under conditions of high aerosol acidity, heterogeneous reactions became one of the major pathways for the formation of nitrate at both cities. These findings provided new insights in our understanding of the spatial and temporal variations in aerosol acidity in Beijing and Chongqing, as well as those reported in other cities in China.

The Influence of Oceanic Air Masses on Concentration of Major Ions and Trace Metals in PM2.5 Fraction at a Coastal European Suburban Site

2014 ◽  
Vol 226 (1) ◽  
Author(s):  
Jorge Moreda-Piñeiro ◽  
Isabel Turnes-Carou ◽  
Elia Alonso-Rodríguez ◽  
Carmen Moscoso-Pérez ◽  
Gustavo Blanco-Heras ◽  
...  
Keyword(s):  
Trace Metals ◽  
Major Ions ◽  
Air Masses ◽  
Suburban Site

High aerosol acidity despite declining atmospheric sulfate concentrations over the past 15 years

2016 ◽  
Vol 9 (4) ◽  
pp. 282-285 ◽  
Author(s):  
Rodney J. Weber ◽  
Hongyu Guo ◽  
Armistead G. Russell ◽  
Athanasios Nenes
Keyword(s):  
The Past ◽  
Aerosol Acidity

scholarly journals Understanding the anthropogenic influence on formation of biogenic secondary organic aerosols in Denmark via analysis of organosulfates and related oxidation products

2014 ◽  
Vol 14 (17) ◽  
pp. 8961-8981 ◽  
Author(s):  
Q. T. Nguyen ◽  
M. K. Christensen ◽  
F. Cozzi ◽  
A. Zare ◽  
A. M. K. Hansen ◽  
...  
Keyword(s):  
Organic Acids ◽  
Long Range ◽  
Secondary Organic Aerosols ◽  
Global Radiation ◽  
Organic Aerosols ◽  
Photochemical Reactions ◽  
Common Mechanism ◽  
Aerosol Acidity ◽  
Local Impacts ◽  
Concentration Levels

Abstract. Anthropogenic emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) may affect concentration levels and composition of biogenic secondary organic aerosols (BSOA) through photochemical reactions with biogenic organic precursors to form organosulfates and nitrooxy organosulfates. We investigated this influence in a field study from 19 May to 22 June, 2011 at two sampling sites in Denmark. Within the study, we identified a substantial number of organic acids, organosulfates and nitrooxy organosulfates in the ambient urban curbside and semi-rural background air. A high degree of correlation in concentrations was found among a group of specific organic acids, organosulfates and nitrooxy organosulfates, which may originate from various precursors, suggesting a common mechanism or factor affecting their concentration levels at the sites. It was proposed that the formation of those species most likely occurred on a larger spatial scale, with the compounds being long-range transported to the sites on the days with the highest concentrations. The origin of the long-range transported aerosols was investigated using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model in addition to modeled emissions of related precursors, including isoprene and monoterpenes using the global Model of Emissions of Gases and Aerosols from Nature (MEGAN) and SO2 emissions using the European Monitoring and Evaluation Program (EMEP) database. The local impacts were also studied by examining the correlation between selected species, which showed significantly enhanced concentrations at the urban curbside site and the local concentrations of various gases, including SO2, ozone (O3), NOx, aerosol acidity and other meteorological conditions. This investigation showed that an inter-play of the local parameters such as the aerosol acidity, NOx, SO2, relative humidity (RH), temperature and global radiation seemed to affect the concentration level of those species, suggesting the influence of aqueous aerosol chemistry. The local impacts, however, seemed minor compared to the regional impacts. The total concentrations of organosulfates and nitrooxy organosulfates, on average, contributed to approximately 0.5–0.8% of PM1 mass at the two sampling sites.

Organic and elemental carbon aerosols at a suburban site

2012 ◽  
Vol 113 ◽  
pp. 13-21 ◽  
Author(s):  
Aparna Satsangi ◽  
Tripti Pachauri ◽  
Vyoma Singla ◽  
Anita Lakhani ◽  
K. Maharaj Kumari
Keyword(s):  
Elemental Carbon ◽  
Carbon Aerosols ◽  
Suburban Site
Sign in / Sign up

Export Citation Format

Share Document