Atmospheric aerosols parameters behavior and its association with meteorological activities variables over western Indian tropical semi-urban site i.e., Udaipur

2016 ◽  
Author(s):  
B. M. Vyas ◽  
Abhishek Saxenna ◽  
Chhagan Panwar
Keyword(s):  
Atmospheric Aerosols ◽  
Urban Site

scholarly journals Properties of aerosols and formation mechanisms over southern China during the monsoon season

2016 ◽  
Author(s):  
Weihua Chen ◽  
Xuemei Wang ◽  
Jason Blake Cohen ◽  
Shengzhen Zhou ◽  
Zhisheng Zhang ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Atmospheric Aerosols ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Southern China ◽  
Monsoon Season ◽  
Sea Salt ◽  
Urban Site ◽  
Chemical Components ◽  
Formation Mechanisms

Abstract. Measurements of size-resolved aerosols from 0.25 to 18 μm were conducted at three sites (urban, suburban and background sites) and used in tandem with an atmospheric transport model to study the size distribution and formation of atmospheric aerosols in southern China during the monsoon season (May–June) in 2010. The mass distribution showed the majority of chemical components were found in the smaller size bins (< 2.5 μm). Sulfate, was found to be strongly correlated with aerosol water, and anti-correlated with atmospheric SO2, hinting at aqueous-phase reactions being the main formation pathway. Nitrate was the only major species that showed a bi-modal distribution at the urban site, and was dominated by the coarse mode in the other two sites, suggesting that an important component of nitrate formation is chloride depletion of sea salt transported from the South China Sea. In addition to these aqueous-phase reactions and interactions with sea salt aerosols, new particle formation, chemical aging, and long-range transport from upwind urban or biomass burning regions were also found to be important in at least some of the sights on some of the days. This work therefore summarizes the different mechanisms that significantly impact the aerosol chemical composition during the Monsoon over southern China.

scholarly journals Characterising mass-resolved mixing state of black carbon in Beijing using a morphology-independent measurement method

2020 ◽  
Vol 20 (6) ◽  
pp. 3645-3661 ◽  
Author(s):  
Chenjie Yu ◽  
Dantong Liu ◽  
Kurtis Broda ◽  
Rutambhara Joshi ◽  
Jason Olfert ◽  
...  
Keyword(s):  
Black Carbon ◽  
Atmospheric Aerosols ◽  
Particle Morphology ◽  
Urban Site ◽  
Inversion Method ◽  
Mixing State ◽  
State Index ◽  
Cloud Scavenging ◽  
Highly Correlated ◽  
State Mixing

Abstract. Refractory black carbon (rBC) in the atmosphere is known for its significant impacts on climate. The relationship between the microphysical and optical properties of rBC remains poorly understood and is influenced by its size and mixing state. Mixing state also influences its cloud scavenging potential and thus atmospheric lifetime. This study presents a coupling of a centrifugal particle mass analyser (CPMA) and a single-particle soot photometer (SP2) for the morphology-independent quantification of the mixing state of rBC-containing particles, used in the urban site of Beijing as part of the Air Pollution and Human Health–Beijing (APHH-Beijing) project during winter (10 November–10 December 2016) and summer (18 May–25 June 2017). This represents a highly dynamic polluted environment with a wide variety of conditions that could be considered representative of megacity area sources in Asia. An inversion method (used for the first time on atmospheric aerosols) is applied to the measurements to present two-variable distributions of both rBC mass and total mass of rBC-containing particles and calculate the mass-resolved mixing state of rBC-containing particles, using previously published metrics. The mass ratio between non-rBC material and rBC material (MR) is calculated to determine the thickness of a hypothetical coating if the rBC and other material followed a concentric sphere model (the equivalent coating thickness). The bulk MR (MRbulk) was found to vary between 2 and 12 in winter and between 2 and 3 in summer. This mass-resolved mixing state is used to derive the mass-weighted mixing state index for the rBC-containing particles (χrBC). χrBC quantifies how uniformly the non-rBC material is distributed across the rBC-containing-particle population, with 100 % representing uniform mixing. The χrBC in Beijing varied between 55 % and 70 % in winter depending on the dominant air masses, and χrBC was highly correlated with increased MRbulk and PM1 mass concentration in winter, whereas χrBC in summer varied significantly (ranging 60 %–75 %) within the narrowly distributed MRbulk and was found to be independent of air mass sources. In some model treatments, it is assumed that more atmospheric ageing causes the BC to tend towards a more homogeneous mixture, but this leads to the conclusion that the MRbulk may only act as a predictor of χrBC in winter. The particle morphology-independent and mass-based information on BC mixing used in this and future studies can be applied to mixing-state-aware models investigating atmospheric rBC ageing.

scholarly journals Atmospheric aerosols in Rome, Italy: sources, dynamics and spatial variations during two seasons

2016 ◽  
Vol 16 (23) ◽  
pp. 15277-15299 ◽  
Author(s):  
Caroline Struckmeier ◽  
Frank Drewnick ◽  
Friederike Fachinger ◽  
Gian Paolo Gobbi ◽  
Stephan Borrmann
Keyword(s):  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
Ground Level ◽  
Organic Aerosol ◽  
Saharan Dust ◽  
Urban Site ◽  
Temporal Behaviour ◽  
Urban Location ◽  
Polycyclic Aromatic ◽  
Primary Emissions

Abstract. Investigations on atmospheric aerosols and their sources were carried out in October/November 2013 and May/June 2014 consecutively in a suburban area of Rome (Tor Vergata) and in central Rome (near St Peter's Basilica). During both years a Saharan dust advection event temporarily increased PM10 concentrations at ground level by about 12–17 µg m−3. Generally, in October/November the ambient aerosol was more strongly influenced by primary emissions, whereas higher relative contributions of secondary particles (sulfate, aged organic aerosol) were found in May/June. Absolute concentrations of anthropogenic emission tracers (e.g. NOx, CO2, particulate polycyclic aromatic hydrocarbons, traffic-related organic aerosol) were generally higher at the urban location. Positive matrix factorization was applied to the PM1 organic aerosol (OA) fraction of aerosol mass spectrometer (HR-ToF-AMS) data to identify different sources of primary OA (POA): traffic, cooking, biomass burning and (local) cigarette smoking. While biomass burning OA was only found at the suburban site, where it accounted for the major fraction of POA (18–24 % of total OA), traffic and cooking were more dominant sources at the urban site. A particle type associated with cigarette smoke emissions, which is associated with a potential characteristic marker peak (m∕z 84, C5H10N+, a nicotine fragment) in the mass spectrum, was only found in central Rome, where it was emitted in close vicinity to the measurement location. Regarding secondary OA, in October/November, only a very aged, regionally advected oxygenated OA was found, which contributed 42–53 % to the total OA. In May/June total oxygenated OA accounted for 56–76 % of the OA. Here a fraction (18–26 % of total OA) of a fresher, less oxygenated OA of more local origin was also observed. New particle formation events were identified from measured particle number concentrations and size distributions in May/June 2014 at both sites. While they were observed every day at the urban location, at the suburban location they were only found under favourable meteorological conditions, but were independent of advection of the Rome emission plume. Particles from sources in the metropolitan area of Rome and particles advected from outside Rome contributed 42–70 and 30–58 % to the total measured PM1, respectively. Apart from the general aerosol characteristics, in this study the properties (e.g. emission strength) and dynamics (e.g. temporal behaviour) of each identified aerosol type is investigated in detail to provide a better understanding of the observed seasonal and spatial differences.

Study of aerosol-type characteristics and sources using MAX-DOAS measurement during haze at an urban site in the Fenwei Plain

2020 ◽  
Author(s):  
Xiaomei Li ◽  
Pinhua Xie ◽  
Ang Li
Keyword(s):  
Atmospheric Aerosols ◽  
Fine Particles ◽  
Global Climate ◽  
Pollution Source ◽  
Source Analysis ◽  
Urban Site ◽  
Industrial Emissions ◽  
Near Surface ◽  
Wide Range ◽  
Aerosol Type

&lt;p&gt;Atmospheric aerosols range in diameter from a few nanometers to tens of micrometers, and they have direct or indirect effects on atmospheric radiation assessments, global climate change, local air quality and visibility, and human health. In particular, during the high season of haze in autumn and winter, atmospheric aerosols are more conducive to transform and accumulate. In this paper, we used the aerosol optical thickness (AOD) and aerosol profile obtained by MAX-DOAS instrument to study the characteristics of aerosol-type, vertical distribution characteristics of near-surface aerosol, and pollution source analysis. From December 30, 2018, to January 27, 2019, we conducted MAX-DOAS observations on Sanmenxia Environmental Protection Bureau. According to the relative humidity data and ion chromatography data, we analyzed the correlation between AOD and PM&lt;sub&gt;2.5&lt;/sub&gt;, the result show that aerosols are mainly fine particles, and most of them are nitrates. The near-surface aerosol extinction coefficient obtained by MAX-DOAS was compared with the PM&lt;sub&gt;2.5&lt;/sub&gt; and PM&lt;sub&gt;10&lt;/sub&gt; concentrations measured by unmanned aerial vehicle (UAV). Aerosol particles showed an increasing trend from the ground to 500 m. Combined with the wind field information and the backward trajectory of the air mass during the haze, we found that the continuous heavy pollution was caused by the transportation of polluted air masses in the northeast, along with local industrial emissions and other sources of emissions, which resulted in a wide range and long-term accumulation of pollutants under continuous and steady conditions.&lt;/p&gt;

A study on trace elemental composition of atmospheric aerosols at a semi-arid urban site using ICP-MS technique

2006 ◽  
Vol 40 (1) ◽  
pp. 136-146 ◽  
Author(s):  
P. Chandra Mouli ◽  
S. Venkata Mohan ◽  
V. Balaram ◽  
M. Praveen Kumar ◽  
S. Jayarama Reddy
Keyword(s):  
Elemental Composition ◽  
Atmospheric Aerosols ◽  
Urban Site ◽  
Icp Ms ◽  
Trace Elemental ◽  
Semi Arid

scholarly journals Atmospheric aerosols in Rome, Italy: Sources, dynamics and spatial variations during two seasons

2016 ◽  
Author(s):  
Caroline Struckmeier ◽  
Frank Drewnick ◽  
Friederike Fachinger ◽  
Gian Paolo Gobbi ◽  
Stephan Borrmann
Keyword(s):  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
Polyaromatic Hydrocarbons ◽  
Ground Level ◽  
Organic Aerosol ◽  
Saharan Dust ◽  
Urban Site ◽  
Temporal Behaviour ◽  
Urban Location ◽  
Primary Emissions

Abstract. Investigations on atmospheric aerosols and their sources were performed during October/November 2013 and May/June 2014 subsequently in a suburban area of Rome (Tor Vergata) and in central Rome (near St. Peter's Basilica). During both years a Saharan dust advection event temporarily increased PM10 concentrations at ground level by approximately 10 µg m−3. Generally, during Oct/Nov the ambient aerosol was more strongly influenced by primary emissions, whereas higher relative contributions of secondary particles (sulphate, aged organic aerosol) were found during May/June. Absolute concentrations of anthropogenic emission tracers (e.g. NOx, CO2, particulate polyaromatic hydrocarbons, traffic-related organic aerosol) were generally higher at the urban location. Positive matrix factorisation was applied to the PM1 organic aerosol (OA) fraction of aerosol mass spectrometer (HR-ToF-AMS) data in order to identify different sources of primary OA (POA): traffic, cooking, biomass burning, and (local) cigarette smoking. While biomass burning OA was only found at the suburban site, where it accounted for the major fraction of POA (18–24 % of total OA), traffic and cooking were more dominant sources at the urban site. A particle type associated with cigarette smoke emissions, which is associated with a potential characteristic marker peak (m/z 84, C5H10N+, a nicotine fragment) in the mass spectrum, was only found in central Rome, where it was emitted in close vicinity to the measurement location. Regarding secondary OA, in Oct/Nov, only a very aged, regionally advected oxygenated OA was found, which contributed 42–53 % to the total OA. In May/June total oxygenated OA accounted for 56–76 % of the OA. Here also a fraction (18–26 % of total OA) of a fresher, less oxygenated OA of more local origin was observed. New particle formation events were identified from measured particle number concentrations and size distributions during May/June 2014 at both sites. While they were observed every day at the urban location, at the suburban location they were only found under favourable meteorological conditions, but independent of advection of the Rome emission plume. Particles from sources in the metropolitan area of Rome and particles advected from outside Rome contributed 42–70 % and 30–58 % to total measured PM1, respectively. Apart from the general aerosol characteristics, in this study the properties (e.g. emission strength) and dynamics (e.g. temporal behaviour) of each identified aerosol type is investigated in detail in order to provide a better understanding of the observed seasonal and spatial differences.

scholarly journals Organosulfates in atmospheric aerosols in Shanghai, China: seasonal and interannual variability, origin, and formation mechanisms

2020 ◽  
Author(s):  
Yao Wang ◽  
Yue Zhao ◽  
Yuchen Wang ◽  
Jian-Zhen Yu ◽  
Jingyuan Shao ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Atmospheric Aerosols ◽  
Dominant Role ◽  
Fine Particulate Matter ◽  
Eastern China ◽  
Anthropogenic Pollution ◽  
Liquid Water Content ◽  
Urban Site ◽  
Formation Mechanisms ◽  
Ambient Aerosols

Abstract. Organosulfates (OS) are ubiquitous in the atmosphere and serve as important tracers for secondary organic aerosols (SOA). Despite intense research over years, the abundance, origin, and formation mechanisms of OS in ambient aerosols, in particular in regions with severe anthropogenic pollution, are still not well understood. In this study, we collected filter samples of ambient fine particulate matter (PM2.5) over four seasons in both 2015/2016 and 2018/2019 at an urban site in Shanghai, China, and comprehensively characterized the OS species in these PM2.5 samples using a liquid chromatography coupled to a high resolution mass spectrometer (UPLC-ESI-QToF-MS). We find that while the concentration of organic aerosol (OA) decreased by 29 % in 2018/2019, compared to that in 2015/2016, the annually averaged concentrations of 35 quantified OS were similar in two years (65.5 ± 77.5 ng m−3 in 2015/2016 versus 59.4 ± 79.7 ng m−3 in 2018/2019), suggesting an increased contribution of SOA to OA in 2018/2019 than in 2015/2016. Isoprene- and monoterpene-derived OS are the two most abundant OS families, on average accounting for 36.3 % and 31.0 % of the quantified OS concentrations, respectively, suggesting an important contribution of biogenic emissions to the production of OS and SOA in Shanghai. The abundance of biogenic OS, particularly those arising from isoprene, exhibited strong seasonality (peaked in summer) but no significant interannual variability. In contrast, anthropogenic OS such as diesel-derived ones had little seasonal variability and declined obviously in 2018/2019 compared with that in 2015/2016. This reflects a significant change in precursor emissions in eastern China in recent years. The C2/C3 OS species that have both biogenic and anthropogenic origins averagely contributed to 19.0 % of the quantified OS, with C2H3O6S−, C3H5O5S−, and C3H5O6S− being the most abundant ones, together accounting for 76 % of C2/C3 OS concentrations. 2-Methyltetrol sulfate (2-MT-OS, C5H11O7S−) and monoterpene-derived C10H16NO7S− were the most abundant OS and nitrooxy-OS in summer, contributing to 31 % and 5 % of the quantified OS, respectively. The substantially larger concentration ratio of 2-MT-OS to 2-methylglyceric acid sulfate (2-MA-OS, C4H7O7S−) in summer (6.8–7.8) than in other seasons (0.31–0.78) implies that low-NOx oxidation pathways played a dominant role in isoprene-derived SOA formation in summer, while high-NOx reaction pathways were more important in other seasons. We further find that the production of OS was largely controlled by the level of Ox (Ox = O3 + NO2), namely, the photochemistry of OS precursors, in particular in summer, though sulfate concentration, aerosol acidity, as well as aerosol liquid water content (ALWC) that could affect the heterogeneous chemistry of reactive intermediates leading to OS formation also played a role. Our study provides valuable insights into the characteristics and mechanisms of OS formation in a typical Chinese megacity and implies that mitigation of Ox pollution can effectively reduce the production of OS and SOA in eastern China.

scholarly journals New particle formation at urban and high-altitude remote sites in the south-eastern Iberian Peninsula

2020 ◽  
Author(s):  
Juan Andrés Casquero-Vera ◽  
Hassan Lyamani ◽  
Lubna Dada ◽  
Simo Hakala ◽  
Pauli Paasonen ◽  
...  
Keyword(s):  
High Altitude ◽  
Atmospheric Aerosols ◽  
Global Climate ◽  
Cloud Condensation Nuclei ◽  
Particle Formation ◽  
Aerosol Size Distribution ◽  
Urban Site ◽  
Special Importance ◽  
New Particle Formation ◽  
Remote Sites

Abstract. A substantial fraction of the atmospheric aerosols originates from secondary new particle formation (NPF), where atmospheric vapours are transformed into particles that subsequently grow to larger sizes, affecting human health and the climate. In this study, we investigate aerosol size distributions at two stations located close to each other (~ 20 km), but at different altitudes: urban (UGR; 680 m a.s.l.) and high-altitude remote (SNS; 2500 m a.s.l.) site, both in the area of Granada, Spain, and part of AGORA observatory (Andalusian Global ObseRvatory of the Atmosphere). The analysis shows a significant contribution of nucleation mode aerosol particles to the total aerosol number concentration at both sites, with a contribution of 47 % and 48 % at SNS and UGR, respectively. Due to the important contribution of NPF events to the total aerosol number concentrations and their high occurrence frequency (> 70 %) during the study period, a detailed analysis of NPF events is done in order to get insight into the possible mechanisms and processes involved in NPF events at these contrastive sites. At SNS, NPF is found to be associated with the transport of gaseous precursors from lower altitudes by orographic buoyant upward flows. However, NPF events at SNS site are always observed from the smallest measured sizes of the aerosol size distribution (4 nm), implying that NPF takes place in or in the vicinity of the high-altitude SNS station rather than transported from lower altitudes. Although NPF events at the mountain site seem to be connected with those occurring at the urban site, growth rates (GR) at SNS are higher than those at UGR site (GR7–25 of 6.9 and 4.5 nm h−1 and GR4–7 of 4.1 and 3.6 nm h−1 at SNS and UGR, respectively). This fact could have a special importance on the production of cloud condensation nuclei (CCN) and therefore on cloud formations which may affect regional/global climate, since larger GR at mountain sites could be translated to larger survival probability of NPF particles to reach CCN sizes, due to shorter time needed for the growth. The analysis of sulfuric acid (H2SO4) shows that the contribution of H2SO4 is able to explain a minimal fraction contribution to the observed GRs at both sites (

Quantification of nitroaromatic compounds in atmospheric fine particulate matter in Hong Kong over 3 years: field measurement evidence for secondary formation derived from biomass burning emissions

2016 ◽  
Vol 13 (4) ◽  
pp. 665 ◽  
Author(s):  
Ka Shing Chow ◽  
X. H. Hilda Huang ◽  
Jian Zhen Yu
Keyword(s):  
Hong Kong ◽  
Particulate Matter ◽  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
Matrix Effects ◽  
Nitroaromatic Compounds ◽  
Urban Site ◽  
Brown Carbon ◽  
North East ◽  
Secondary Formation

Environmental context Nitroaromatic compounds constitute an important portion of brown carbon and thereby contribute to the light-absorbing properties of atmospheric aerosols. We report their abundance in Hong Kong over 3 years and show that they were mainly associated with aged biomass burning particles. Knowledge of the abundance and sources of nitroaromatic compounds could assist in evaluating their contribution to brown carbon and in apportioning secondary organic aerosols from biomass burning sources. Abstract Biomass burning is a major source of atmospheric aerosols on both global and regional scales. Among the large number of unidentified organic compounds related to biomass burning, nitroaromatic compounds (NACs) have drawn attention because of their UV light-absorbing ability. In this study, an analytical method based on liquid chromatography–mass spectrometry was used to quantify a group of NACs (nitrophenol, methylnitrophenols, dimethylnitrophenol, nitrocatechol and methylnitrocatechols) in aerosol samples. The nitrocatechol–metal complex interference, sample matrix effects, sample stability, precision and reproducibility were investigated. The method detection limits ranged from 0.10 to 0.23ngmL–1 and the recoveries for the target NACs were in the range of 96–102%. The method was applied to a total of 184 ambient PM2.5 samples (particulate matter of 2.5µm or less in aerodynamic diameter) collected at an urban site in Hong Kong over 3 years (2010–2012). The NACs quantified showed a distinct seasonal variation with higher concentrations in autumn and winter (3.6–21.0ngm–3), coinciding with more biomass burning activities coming from the regions west and north-east to Hong Kong, and lower levels during spring and summer (0.3–3.8ngm–3). The good correlations between NACs and levoglucosan (R=0.82), a known biomass burning tracer compound, support the common origin from biomass burning. Moderate to good correlations between NACs and nitrate suggest that they might be products of secondary formation processes involving the same precursor gases (e.g. NOx). Additional lines of circumstantial evidence were also found and presented in the paper to support secondary formation derived from biomass burning as the main contributing source of NACs.

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