scholarly journals Spatial and seasonal variability of the mass concentration and chemical composition of PM2.5 in Poland

2013 ◽  
Vol 7 (1) ◽  
pp. 41-58 ◽  
Author(s):  
Wioletta Rogula-Kozłowska ◽  
Krzysztof Klejnowski ◽  
Patrycja Rogula-Kopiec ◽  
Leszek Ośródka ◽  
Ewa Krajny ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Seasonal Variability ◽  
Mass Concentration

scholarly journals Particle hygroscopicity and its link to chemical composition in the urban atmosphere of Beijing, China during summertime

2015 ◽  
Vol 15 (8) ◽  
pp. 11495-11524 ◽  
Author(s):  
Z. J. Wu ◽  
J. Zheng ◽  
D. J. Shang ◽  
Z. F. Du ◽  
Y. S. Wu ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Concentration ◽  
Cloud Condensation Nuclei ◽  
Empirical Relationship ◽  
Urban Atmosphere ◽  
High Time Resolution ◽  
Hygroscopic Growth ◽  
Hygroscopic Properties ◽  
Beijing China ◽  
Measurement Period

Abstract. Simultaneous measurements of particle number size distribution, particle hygroscopic properties, and size-resolved chemical composition were made during the summer of 2014 in Beijing, China. During the measurement period, the median hygroscopicity parameters (κ) of 50, 100, 150, 200, and 250 nm particles are respectively 0.15, 0.19, 0.22, 0.27, and 0.29, showing an increasing trend with increasing particle size. When PM2.5 mass concentration is greater than 50 μg m−3, the fractions of the hydrophilic mode for 150, 250, 350 nm particles increased towards 1 as PM2.5 mass concentration increased. This indicates that aged particles dominated during severe pollution periods in the atmosphere of Beijing. Particle hygroscopic growth can be well predicted using high time-resolution size-resolved chemical composition derived from AMS measurement on a basis of ZSR mixing rule. An empirical relationship between κ of organic fraction (κorg) and oxygen to carbon ratio (O : C) (κorg= 0.08·O : C+0.02) is obtained. During new particle formation event associating with strongly active photochemistry, the hygroscopic growth factor or κ of newly formed particles is greater than for particle with the same sizes during non-NPF periods. A quick transformation from external mixture to internal mixture for pre-existing particles (for example 250 nm particle) was observed. Such transformations can modify the state of mixture of pre-exiting particles and thus modify properties such as the light absorption coefficient and cloud condensation nuclei activation.

In vitro particulate matter toxicity relates to seasonal variability in chemical composition

2013 ◽  
Vol 221 ◽  
pp. S108
Author(s):  
Alvaro Osornio Vargas ◽  
Natalia Manzano-Leon ◽  
Raul Quintana-Belmares ◽  
Brisa Sanchez ◽  
Alexandra Sitarik ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Chemical Composition ◽  
Seasonal Variability

PM 10 and PM 2.5 mass concentration, chemical composition, and size distribution measurements at three different sites in the Ruhr-area, Germany

1999 ◽  
Vol 30 ◽  
pp. S45-S46 ◽  
Author(s):  
T.A.J. Kuhlbusch ◽  
A.C. John ◽  
H. Fissan ◽  
K.-G. Schmidt ◽  
F. Schmidt ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
Mass Concentration ◽  
Ruhr Area ◽  
Pm 2.5 ◽  
Pm 10

scholarly journals Chemical characteristics of submicron particles at the central Tibetan Plateau: insights from aerosol mass spectrometry

2018 ◽  
Vol 18 (1) ◽  
pp. 427-443 ◽  
Author(s):  
Jianzhong Xu ◽  
Qi Zhang ◽  
Jinsen Shi ◽  
Xinlei Ge ◽  
Conghui Xie ◽  
...  
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Tibetan Plateau ◽  
Mass Transport ◽  
Mass Concentration ◽  
Organic Aerosol ◽  
Early Morning ◽  
Monsoon Period ◽  
Air Mass ◽  
Aerosol Mass

Abstract. Recent studies have revealed a significant influx of anthropogenic aerosol from South Asia to the Himalayas and Tibetan Plateau (TP) during pre-monsoon period. In order to characterize the chemical composition, sources, and transport processes of aerosol in this area, we carried out a field study during June 2015 by deploying a suite of online instruments including an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-AMS) and a multi-angle absorption photometer (MAAP) at Nam Co station (90∘57′ E, 30∘46′ N; 4730 m a.s.l.) at the central of the TP. The measurements were made at a period when the transition from pre-monsoon to monsoon occurred. The average ambient mass concentration of submicron particulate matter (PM1) over the whole campaign was ∼ 2.0 µg m−3, with organics accounting for 68 %, followed by sulfate (15 %), black carbon (8 %), ammonium (7 %), and nitrate (2 %). Relatively higher aerosol mass concentration episodes were observed during the pre-monsoon period, whereas persistently low aerosol concentrations were observed during the monsoon period. However, the chemical composition of aerosol during the higher aerosol concentration episodes in the pre-monsoon season was on a case-by-case basis, depending on the prevailing meteorological conditions and air mass transport routes. Most of the chemical species exhibited significant diurnal variations with higher values occurring during afternoon and lower values during early morning, whereas nitrate peaked during early morning in association with higher relative humidity and lower air temperature. Organic aerosol (OA), with an oxygen-to-carbon ratio (O ∕ C) of 0.94, was more oxidized during the pre-monsoon period than during monsoon (average O ∕ C ratio of 0.72), and an average O ∕ C was 0.88 over the entire campaign period, suggesting overall highly oxygenated aerosol in the central TP. Positive matrix factorization of the high-resolution mass spectra of OA identified two oxygenated organic aerosol (OOA) factors: a less oxidized OOA (LO-OOA) and a more oxidized OOA (MO-OOA). The MO-OOA dominated during the pre-monsoon period, whereas LO-OOA dominated during monsoon. The sensitivity of air mass transport during pre-monsoon with synoptic process was also evaluated with a 3-D chemical transport model.

scholarly journals Measurement report: The effect of aerosol chemical composition on light scattering due to the hygroscopic swelling effect

2021 ◽  
Author(s):  
Rongmin Ren ◽  
Zhanqing Li ◽  
Peng Yan ◽  
Yuying Wang ◽  
Hao Wu ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Mass Fraction ◽  
Mass Concentration ◽  
Negative Impact ◽  
Positive Impact ◽  
Parameterization Scheme ◽  
Ambient Aerosols ◽  
Inorganic Matter ◽  
Aerosol Hygroscopicity

Abstract. Liquid water in aerosol particles has a significant effect on optical properties, especially on light scattering, whose dependence on chemical composition is investigated here using measurements made in southern Beijing in 2019. The effect is measured by the enhancement of aerosol hygroscopic factor, f(RH = 85 %, 525 nm), which is found to be positively and negatively impacted by the proportions of inorganic and organic matters respectively. Black carbon is also negatively correlated. The positive impact is more robust when the inorganic matter mass fraction was smaller than 40 % (correlation coefficient, R = 0.93) which becomes weaker as the inorganic matter mass fraction gets larger (R = 0.48). A similar pattern was also found in the negative impact for organic matter mass fraction. Nitrate played a more significant role in aerosol hygroscopicity than sulfate in Beijing. However, the deliquescence point of ambient aerosols was at about RH = 80 % when the ratio of the sulfate mass concentration to the nitrate mass concentration of the aerosol was high (mostly higher than ~4). Two schemes to parameterize f(RH) were developed in accounting for the deliquescent and non-deliquescent effects. Using only one f(RH) parameterization scheme to fit all f(RH) processes would incur large errors. A piecewise parameterization scheme is proposed, which can better describe deliquescence and reduces uncertainties in simulating aerosol hygroscopicity.

Multiphase buffer theory explains contrasts in atmospheric aerosol acidity

Science ◽  
2020 ◽  
Vol 369 (6509) ◽  
pp. 1374-1377 ◽  
Author(s):  
Guangjie Zheng ◽  
Hang Su ◽  
Siwen Wang ◽  
Meinrat O. Andreae ◽  
Ulrich Pöschl ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Atmospheric Aerosol ◽  
Mass Concentration ◽  
Ammonia Emissions ◽  
Human Influence ◽  
Acid Base ◽  
Ph Values ◽  
Aerosol Acidity ◽  
Conjugate Acid ◽  
Buffering Agent

Aerosol acidity largely regulates the chemistry of atmospheric particles, and resolving the drivers of aerosol pH is key to understanding their environmental effects. We find that an individual buffering agent can adopt different buffer pH values in aerosols and that aerosol pH levels in populated continental regions are widely buffered by the conjugate acid-base pair NH4+/NH3 (ammonium/ammonia). We propose a multiphase buffer theory to explain these large shifts of buffer pH, and we show that aerosol water content and mass concentration play a more important role in determining aerosol pH in ammonia-buffered regions than variations in particle chemical composition. Our results imply that aerosol pH and atmospheric multiphase chemistry are strongly affected by the pervasive human influence on ammonia emissions and the nitrogen cycle in the Anthropocene.

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