Seasonal variations of anthropogenic contribution into diurnal behavior of the aerosol and soot mass concentrations and the aerosol hygroscopicity in the suburb of Tomsk

Abstract. There is considerable interest in using low-cost optical particle counters (OPC) to supplement existing routine air quality networks that monitor particle mass concentrations. In order to do this, low-cost OPC data needs to be cross-comparable with particle mass reference instrumentation, and as yet, there is no widely agreed methodology. Aerosol hygroscopicity is known to be a key parameter to consider when correcting particle mass concentrations derived from a low-cost OPC, particularly at high ambient Relative Humidity (RH). Correction factors have been developed that apply κ-Köhler theory to correct for the influence of water uptake by hygroscopic aerosols. We have used datasets of co-located reference particle measurements and a low-cost OPC (OPC-N2, Alphasense), collected in four cities in three continents, to explore the performance of this correction factor. We report evidence that the elevated particle mass concentrations, reported by the low-cost OPC relative to reference instrumentation, is due to bulk aerosol hygroscopicity under different RH conditions, which is determined by aerosol composition and in particular the levels of hygroscopic aerosols (sulphate and nitrate). We exploit measurements made in volcanic plumes in Nicaragua, that are predominantly composed of sulphate aerosol, as a natural experiment to demonstrate this behaviour in the ambient atmosphere, with the observed humidogram closely resembling the calculated pure sulphuric acid humidogram. The results indicate that the particle mass concentrations derived from low-cost OPCs during periods of high RH (> 60 %) need to be corrected for aerosol hygroscopic growth. We employed a correction factor based on κ-Köhler theory and observed corrected OPC-N2 PM2.5 mass concentrations to be within 33 % of reference measurements at all sites. The results indicated that an in situ derived κ (using suitable reference instrumentation) would lead to the most accurate correction relative to co-located reference instruments. Applying literature κ in the correction factor also resulted in improved performance of OPC-N2, to be within 50 % of reference. Therefore, for areas where suitable reference instrumentation for developing a local correction factor is lacking, using a literature κ value can result in a reasonable correction. For locations with low levels of hygroscopic aerosols and RH, a simple calibration against gravimetric measurements (using suitable reference instrumentation) would likely be sufficient. Whilst this study generated correction factors specific for the Alphasense OPC-N2 sensor, the calibration methodology developed is likely amenable to other low cost PM sensors.

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Spatial and Seasonal Variations of PM Concentration and Size Distribution in Manure-Belt Poultry Layer Houses

Transactions of the ASABE ◽

10.13031/trans.12950 ◽

2019 ◽

Vol 62 (2) ◽

pp. 415-427 ◽

Cited By ~ 1

Author(s):

Reyna M. Knight ◽

Xinjie Tong ◽

Zhenyu Liu ◽

Sewoon Hong ◽

Lingying Zhao

Keyword(s):

Particle Size ◽

Particulate Matter ◽

Size Distribution ◽

Seasonal Variations ◽

Size Distributions ◽

Particle Size Distributions ◽

Potential Health ◽

Significant Difference ◽

Autumn And Winter ◽

Mass Concentrations

Abstract. Poultry layer houses are a significant source of particulate matter (PM) emissions, which potentially affect worker and animal health. Particulate matter characteristics, such as concentration and size distribution inside layer houses, are critical information for assessment of the potential health risks and development of effective PM mitigation technologies. However, this information and its spatial and seasonal variations are lacking for typical layer facilities. In this study, two TSI DustTrak monitors (DRX 8533) and an Aerodynamic Particle Sizer (APS 3321) were used to measure PM mass concentrations and number-weighted particle size distributions in two typical manure-belt poultry layer houses in Ohio in three seasons: summer, autumn, and winter. Bimodal particle size distributions were consistently observed. The average count median diameters (mean ±SD) were 1.68 ±0.25, 2.16 ±0.31, and 1.87 ±0.07 µm in summer, autumn, and winter, respectively. The average geometric standard deviations of particle size were 2.16 ±0.23, 2.16 ±0.18, and 1.74 ±0.17 in the three seasons, respectively. The average mass concentrations were 67.4 ±54.9, 289.9 ±216.2, and 428.1 ±269.9 µg m-3 for PM2.5; 73.6 ±59.5, 314.6 ±228.9, and 480.8 ±306.5 µg m-3 for PM4; and 118.8 ±99.6, 532.5 ±353.0, and 686.2 ±417.7 µg m-3 for PM10 in the three seasons, respectively. Both statistically significant (p < 0.05) and practically significant (difference of means >20% of smaller value) seasonal variations were observed. Spatial variations were only practically significant for autumn mass concentrations, likely due to external dust infiltration from nearby agricultural activities. The OSHA-mandated permissible exposure limit for respirable PM was not exceeded in any season. Keywords: Air quality, Particulate matter, Poultry housing, Seasonal variation, Spatial variation.

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Seasonal variations of black carbon aerosols and total aerosol mass concentrations over urban environment in India

Atmospheric Environment ◽

10.1016/j.atmosenv.2005.04.004 ◽

2005 ◽

Vol 39 (22) ◽

pp. 4129-4141 ◽

Cited By ~ 44

Author(s):

K. Madhavi Latha ◽

K.V.S. Badarinath

Keyword(s):

Urban Environment ◽

Black Carbon ◽

Seasonal Variations ◽

Aerosol Mass ◽

Carbon Aerosols ◽

Mass Concentrations ◽

Black Carbon Aerosols

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Contrasting source contributions of Arctic black carbon to atmospheric concentrations, deposition flux, and atmospheric and snow radiative effects

10.5194/acp-2021-1091 ◽

2022 ◽

Author(s):

Hitoshi Matsui ◽

Tatsuhiro Mori ◽

Sho Ohata ◽

Nobuhiro Moteki ◽

Naga Oshima ◽

...

Keyword(s):

Solar Radiation ◽

Black Carbon ◽

Seasonal Variations ◽

Climate Impacts ◽

The Arctic ◽

Deposition Flux ◽

Radiative Effect ◽

Radiative Effects ◽

Source Contributions ◽

Mass Concentrations

Abstract. Black carbon (BC) particles in the Arctic contribute to rapid warming of the Arctic by heating the atmosphere and snow and ice surfaces. Understanding the source contributions to Arctic BC is therefore important, but they are not well understood, especially those for atmospheric and snow radiative effects. Here we estimate simultaneously the source contributions of Arctic BC to near-surface and vertically integrated atmospheric BC mass concentrations (MBC_SRF and MBC_COL), BC deposition flux (MBC_DEP), and BC radiative effects at the top of the atmosphere and snow surface (REBC_TOA and REBC_SNOW), and show that the source contributions to these five variables are highly different. In our estimates, Siberia makes the largest contribution to MBC_SRF, MBC_DEP, and REBC_SNOW in the Arctic (defined as > 70° N), accounting for 70 %, 53 %, and 43 %, respectively. In contrast, Asia’s contributions to MBC_COL and REBC_TOA are largest, accounting for 38 % and 45 %, respectively. In addition, the contributions of biomass burning sources are larger (24−34 %) to MBC_DEP, REBC_TOA, and REBC_SNOW, which are highest from late spring to summer, and smaller (4.2−14 %) to MBC_SRF and MBC_COL, whose concentrations are highest from winter to spring. These differences in source contributions to these five variables are due to seasonal variations in BC emission, transport, and removal processes and solar radiation, as well as to differences in radiative effect efficiency (radiative effect per unit BC mass) among sources. Radiative effect efficiency varies by a factor of up to 4 among sources (1465−5439 W g–1) depending on lifetimes, mixing states, and heights of BC and seasonal variations of emissions and solar radiation. As a result, source contributions to radiative effects and mass concentrations (i.e., REBC_TOA and MBC_COL, respectively) are substantially different. The results of this study demonstrate the importance of considering differences in the source contributions of Arctic BC among mass concentrations, deposition, and atmospheric and snow radiative effects for accurate understanding of Arctic BC and its climate impacts.

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Effect of aerosol composition on the performance of low-cost optical particle counter correction factors

Atmospheric Measurement Techniques ◽

10.5194/amt-13-1181-2020 ◽

2020 ◽

Vol 13 (3) ◽

pp. 1181-1193 ◽

Cited By ~ 3

Author(s):

Leigh R. Crilley ◽

Ajit Singh ◽

Louisa J. Kramer ◽

Marvin D. Shaw ◽

Mohammed S. Alam ◽

...

Keyword(s):

Correction Factor ◽

Low Cost ◽

Particle Mass ◽

Ambient Atmosphere ◽

Correction Factors ◽

Aerosol Composition ◽

Kohler Theory ◽

Suitable Reference ◽

Aerosol Hygroscopicity ◽

Mass Concentrations

Abstract. There is considerable interest in using low-cost optical particle counters (OPCs) to supplement existing routine air quality networks that monitor particle mass concentrations. In order to do this, low-cost OPC data need to be comparable with particle mass reference instrumentation; however, there is currently no widely agreed upon methodology to accomplish this. Aerosol hygroscopicity is known to be a key parameter to consider when correcting particle mass concentrations derived from low-cost OPCs, particularly at high ambient relative humidity (RH). Correction factors have been developed that apply κ-Köhler theory to correct for the influence of water uptake by hygroscopic aerosols. We have used datasets of co-located reference particle measurements and low-cost OPC (OPC-N2, Alphasense) measurements, collected in four cities on three continents, to explore the performance of this correction factor. We provide evidence that the elevated particle mass concentrations, reported by the low-cost OPC relative to reference instrumentation, are due to bulk aerosol hygroscopicity under different RH conditions, which is determined by aerosol composition and, in particular, the levels of hygroscopic aerosols (sulfate and nitrate). We exploit measurements made in volcanic plumes in Nicaragua, which are predominantly composed of sulfate aerosol, as a natural experiment to demonstrate this behaviour in the ambient atmosphere; the observed humidogram from these measurements closely resembles the calculated pure sulfuric acid humidogram. The results indicate that the particle mass concentrations derived from low-cost OPCs during periods of high RH (>60 %) need to be corrected for aerosol hygroscopic growth. We employed a correction factor based on κ-Köhler theory and observed that the corrected OPC-N2 PM2.5 mass concentrations were within 33 % of reference measurements at all sites. The results indicated that a κ value derived in situ (using suitable reference instrumentation) would lead to the most accurate correction relative to co-located reference instruments. Applying a κ values from the literature in the correction factor also resulted in improved OPC-N2 performance, with the measurements being within 50 % of the reference values. Therefore, for areas where suitable reference instrumentation for developing a local correction factor is lacking, using a literature κ value can result in a reasonable correction. For locations with low levels of hygroscopic aerosols and low RH values, a simple calibration against gravimetric measurements (using suitable reference instrumentation) would likely be sufficient. Whilst this study generated correction factors specific for the Alphasense OPC-N2 sensor, the calibration methodology developed is likely amenable to other low-cost PM sensors.

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Mass concentrations, seasonal variations, chemical compositions and element sources of PM10 at an urban site in Constantine, northeast Algeria

Journal of Geochemical Exploration ◽

10.1016/j.gexplo.2019.106356 ◽

2019 ◽

Vol 206 ◽

pp. 106356 ◽

Cited By ~ 6

Author(s):

F. Bencharif-Madani ◽

H. Ali-Khodja ◽

A. Kemmouche ◽

A. Terrouche ◽

K. Lokorai ◽

...

Keyword(s):

Seasonal Variations ◽

Urban Site ◽

Chemical Compositions ◽

Mass Concentrations

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Seasonal variations of number size distributions and mass concentrations of atmospheric particles in Beijing

Advances in Atmospheric Sciences ◽

10.1007/bf02918753 ◽

2005 ◽

Vol 22 (3) ◽

pp. 401-407 ◽

Cited By ~ 14

Author(s):

Yu Jianhua ◽

Benjamin Guinot ◽

Yu Tong ◽

Wang Xin ◽

Liu Wenqing

Keyword(s):

Seasonal Variations ◽

Atmospheric Particles ◽

Size Distributions ◽

Mass Concentrations

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Soot Distribution and Thermal Regeneration of Marine Diesel Particulate Filter

10.21203/rs.3.rs-963513/v1 ◽

2021 ◽

Author(s):

Xiangli Wang ◽

Peiyong Ni

Keyword(s):

Diesel Particulate Filter ◽

Particulate Filter ◽

Exhaust Gas ◽

Diesel Particulate ◽

Pressure Drops ◽

Soot Mass ◽

Marine Diesel ◽

Dpf Regeneration ◽

Soot Distribution ◽

Mass Concentrations

Abstract Particles from marine diesel engine exhaust gas have caused serious air pollution and human health. Diesel particulate filter (DPF) can effectively reduce particle emissions from marine diesel engines. The distribution and regeneration of soot in DPF are two important issues. In this paper, a mathematical model of a marine DPF was built up and the particle trap process and the regeneration dynamics were simulated. The results show that the cake soot mass concentrations during trap process increase linearly with the increase of the exhaust gas flows while the depth soot mass concentrations firstly increase linearly and then keep constant. Soot is mainly concentrated in the front and rear portion of the filter and less soot is in the middle. The soot distribution in the cake and depth layer shows the unevenness during the trap and regeneration process. The initial soot loadings have great effects on pressure drops and soot mass concentrations before regeneration, but little effect after regeneration. The exhaust gas temperature heated to 850 K can achieve 94% efficiency for the DPF regeneration. There is no obvious difference in pressure drops and soot mass concentrations between fast heating and slow heating. The heating duration of exhaust gas has an important impact on DPF regeneration.

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