scholarly journals Particle formation at a continental background site: comparison of model results with observations

2003 ◽  
Vol 3 (2) ◽  
pp. 347-359 ◽  
Author(s):  
U. Uhrner ◽  
W. Birmili ◽  
F. Stratmann ◽  
M. Wilck ◽  
I. J. Ackermann ◽  
...  
Keyword(s):  
Particle Size ◽  
Sulphuric Acid ◽  
Particle Number ◽  
Particle Formation ◽  
Box Model ◽  
Rural Site ◽  
Data Sets ◽  
Size Distributions ◽  
Correction Factors ◽  
Particle Size Distributions

Abstract. At Hohenpeissenberg (47° 48' N, 11° 07' E, 988 m asl), a rural site 200--300~m higher than the surrounding terrain, sulphuric acid concentrations, particle size distributions, and other trace gas concentrations were measured over a two and a half year period. Measured particle number concentrations and inferred particle surface area concentrations were compared with box-model simulations for 12 carefully selected data sets collected during the HAFEX experiment (Birmili et al., 2003). The 12 cases were selected after meteorological and aerosol dynamical criteria in order to justify the use of a box-model. The aerosol model included a binary sulphuric acid water nucleation scheme. Calculated nucleation rates were corrected with a factor to match measured and calculated particle number concentrations. For the investigated 12 data sets, the correction factors were smallest for measurements made under stable thermal stratification and low wind conditions, i.e. conditions that are frequently encountered during winter. Correction factors were largest for measurements made under strong convective conditions. Our comparison of measured and simulated particle size distributions suggests that the particle formation process maybe strongly influenced by mixing processes driven by thermal convection and/or wind sheer.

scholarly journals Particle formation at a continental background site: comparison of modelresults with observations

2002 ◽  
Vol 2 (6) ◽  
pp. 2413-2448
Author(s):  
U. Uhrner ◽  
W. Birmili ◽  
F. Stratmann ◽  
M. Wilck ◽  
I. J. Ackermann ◽  
...  
Keyword(s):  
Particle Size ◽  
Sulphuric Acid ◽  
Particle Number ◽  
Particle Formation ◽  
Rural Site ◽  
Size Distributions ◽  
Correction Factors ◽  
Convective Conditions ◽  
Particle Size Distributions ◽  
Measured Particle

Abstract. At Hohenpeissenberg (47°48'N, 11°07'E, 988 m asl), a rural site 200-300 m higher than the surrounding terrain, sulphuric acid concentrations, particle size distributions, and other trace gas concentrations were measured over a two and a half year period. Measured particle number concentrations and inferred particle surface area-concentrations were compared with box-model simulations based on a multimodal lognormal aerosol module that included a binary sulphuric acid water nucleation scheme. The calculated nucleation rates were corrected with a factor to match measured particle number concentrations. These corrections varied over a range of 10-3 - 1017. The correction factors were close to 1 for the measurements made in the winter, which represented stable thermal stratification and low wind conditions. In contrast, the correction factors were the largest for measurements made under strong convective conditions. Our comparison of measured and simulated particle size distributions suggest a distant particle-formation process under convective conditions near the interface of the mixed layer and the entrainment zone, followed by downward transport and particle growth. For stable stratification and low winds, our comparisons suggest that particles formed close to the measurement site.

scholarly journals Particle size distributions in the Eastern Mediterranean troposphere

2008 ◽  
Vol 8 (22) ◽  
pp. 6729-6738 ◽  
Author(s):  
N. Kalivitis ◽  
W. Birmili ◽  
M. Stock ◽  
B. Wehner ◽  
A. Massling ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Particle Size ◽  
Eastern Mediterranean ◽  
Particle Formation ◽  
Particle Nucleation ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Air Masses ◽  
Crete Island ◽  
Particle Sizer

Abstract. Atmospheric particle size distributions were measured on Crete island, Greece in the Eastern Mediterranean during an intensive field campaign between 28 August and 20 October, 2005. Our instrumentation combined a differential mobility particle sizer (DMPS) and an aerodynamic particle sizer (APS) and measured number size distributions in the size range 0.018 μm–10 μm. Four time periods with distinct aerosol characteristics were discriminated, two corresponding to marine and polluted air masses, respectively. In marine air, the sub-μm size distributions showed two particle modes centered at 67 nm and 195 nm having total number concentrations between 900 and 2000 cm−3. In polluted air masses, the size distributions were mainly unimodal with a mode typically centered at 140 nm, with number concentrations varying between 1800 and 2900 cm−3. Super-μm particles showed number concentrations in the range from 0.01 to 2.5 cm−3 without any clear relation to air mass origin. A small number of short-lived particle nucleation events were recorded, where the calculated particle formation rates ranged between 1.1–1.7 cm−3 s−1. However, no particle nucleation and growth events comparable to those typical for the continental boundary layer were observed. Particles concentrations (Diameter <50 nm) were low compared to continental boundary layer conditions with an average concentration of 300 cm−3. The production of sulfuric acid and its subsequently condensation on preexisting particles was examined with the use of a simplistic box model. These calculations suggested that the day-time evolution of the Aitken particle population was governed mainly by coagulation and that particle formation was absent during most days.

scholarly journals Particle size distributions in the Eastern Mediterranean troposphere

2008 ◽  
Vol 8 (2) ◽  
pp. 6571-6601
Author(s):  
N. Kalivitis ◽  
W. Birmili ◽  
M. Stock ◽  
B. Wehner ◽  
A. Massling ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Particle Size ◽  
Eastern Mediterranean ◽  
Particle Formation ◽  
Particle Nucleation ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Air Masses ◽  
Crete Island ◽  
Particle Sizer

Abstract. Atmospheric particle size distributions were measured on Crete island, Greece in the Eastern Mediterranean during an intensive field campaign between 28 August and 20 October 2005. Our instrumentation combined a differential mobility particle sizer (DMPS) and an aerodynamic particle sizer (APS) and measured number size distributions in the size range 0.018 μm–10 μm. Four time periods with distinct aerosol characteristics were discriminated, two corresponding to marine and polluted air masses, respectively. In marine air, the sub-μm size distributions showed two particle modes centered at 67 nm and 195 nm having total number concentrations between 900 and 2000 cm−3. In polluted air masses, the size distributions were mainly unimodal with a mode typically centered at 140 nm, with number concentrations varying between 1800 and 2900 cm−3. Super-μm particles showed number concentrations in the range from 0.01 to 2.5 cm−3 without any clear relation to air mass origin. A small number of short-lived particle nucleation events were recorded, where the calculated particle formation rates ranged between 1.1–1.7 cm−3 s−1. However, no particle nucleation and growth events comparable to those typical for the continental boundary layer were observed. Particles concentrations (Diameter <50 nm) were low compared to continental boundary layer conditions with an average concentration of 300 cm−3. The production of sulfuric acid and its subsequently condensation on preexisting particles was examined with the use of a simplistic box model. These calculations suggested that the day-time evolution of the Aitken particle population was governed mainly by coagulation and that particle formation was absent during most days.

scholarly journals Size-resolved particle number emissions in Beijing determined from measured particle size distributions

2020 ◽  
Vol 20 (19) ◽  
pp. 11329-11348 ◽  
Author(s):  
Jenni Kontkanen ◽  
Chenjuan Deng ◽  
Yueyun Fu ◽  
Lubna Dada ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Particle Size ◽  
Air Quality ◽  
Particle Number ◽  
Aerosol Particles ◽  
Urban Environments ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Measured Particle

Abstract. The climate and air quality effects of aerosol particles depend on the number and size of the particles. In urban environments, a large fraction of aerosol particles originates from anthropogenic emissions. To evaluate the effects of different pollution sources on air quality, knowledge of size distributions of particle number emissions is needed. Here we introduce a novel method for determining size-resolved particle number emissions, based on measured particle size distributions. We apply our method to data measured in Beijing, China, to determine the number size distribution of emitted particles in a diameter range from 2 to 1000 nm. The observed particle number emissions are dominated by emissions of particles smaller than 30 nm. Our results suggest that traffic is the major source of particle number emissions with the highest emissions observed for particles around 10 nm during rush hours. At sizes below 6 nm, clustering of atmospheric vapors contributes to calculated emissions. The comparison between our calculated emissions and those estimated with an integrated assessment model GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies) shows that our method yields clearly higher particle emissions at sizes below 60 nm, but at sizes above that the two methods agree well. Overall, our method is proven to be a useful tool for gaining new knowledge of the size distributions of particle number emissions in urban environments and for validating emission inventories and models. In the future, the method will be developed by modeling the transport of particles from different sources to obtain more accurate estimates of particle number emissions.

scholarly journals The contribution of sulphuric acid to atmospheric particle formation and growth: a comparison between boundary layers in Northern and Central Europe

2005 ◽  
Vol 5 (7) ◽  
pp. 1773-1785 ◽  
Author(s):  
V. Fiedler ◽  
M. Dal Maso ◽  
M. Boy ◽  
H. Aufmhoff ◽  
J. Hoffmann ◽  
...  
Keyword(s):  
Sulphuric Acid ◽  
Central Europe ◽  
Growth Rates ◽  
Particle Number ◽  
Particle Growth ◽  
Particle Formation ◽  
Initial Growth ◽  
Size Distributions ◽  
Vapor Source ◽  
Particle Formation And Growth

Abstract. Atmospheric gaseous sulphuric acid was measured and its influence on particle formation and growth was investigated building on aerosol data. The measurements were part of the EU-project QUEST and took place at two different measurement sites in Northern and Central Europe (Hyytiälä, Finland, March-April 2003 and Heidelberg, Germany, March-April 2004). From a comprehensive data set including sulphuric acid, particle number size distributions and meteorological data, particle growth rates, particle formation rates and source rates of condensable vapors were inferred. Growth rates were determined in two different ways, from particle size distributions as well as from a so-called timeshift analysis. Moreover, correlations between sulphuric acid and particle number concentration between 3 and 6 nm were examined and the influence of air masses of different origin was investigated. Measured maximum concentrations of sulphuric acid were in the range from 1x106 to 16x106cm-3. The gaseous sulphuric acid lifetime with respect to condensation on aerosol particles ranged from 2 to 33min in Hyytiälä and from 0.5 to 8 min in Heidelberg. Most calculated values (growth rates, formation rates, vapor source rates) were considerably higher in Central Europe (Heidelberg), due to the more polluted air and higher preexistent aerosol concentrations. Close correlations between H2SO4 and nucleation mode particles (size range: 3-6 nm) were found on most days at both sites. The percentage contribution of sulphuric acid to particle growth was below 10% at both places and to initial growth below 20%. An air mass analysis indicated that at Heidelberg new particles were formed predominantly in air advected from southwesterly directions.

Modelling particle size distributions and secondary particle formation in emulsion polymerisation

Polymer ◽  
1998 ◽  
Vol 39 (26) ◽  
pp. 7099-7112 ◽  
Author(s):  
Emma M. Coen ◽  
Robert G. Gilbert ◽  
Bradley R. Morrison ◽  
Hartmann Leube ◽  
Sarah Peach
Keyword(s):  
Particle Size ◽  
Secondary Particle ◽  
Particle Formation ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Emulsion Polymerisation

scholarly journals Remarkable dynamics of nanoparticles in the urban atmosphere

2011 ◽  
Vol 11 (13) ◽  
pp. 6623-6637 ◽  
Author(s):  
M. Dall'Osto ◽  
A. Thorpe ◽  
D. C. S. Beddows ◽  
R. M. Harrison ◽  
J. F. Barlow ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Urban Areas ◽  
Particle Number ◽  
Road Traffic ◽  
Urban Atmosphere ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Number Count ◽  
Adverse Health Effects

Abstract. Nanoparticles emitted from road traffic are the largest source of respiratory exposure for the general public living in urban areas. It has been suggested that adverse health effects of airborne particles may scale with airborne particle number, which if correct, focuses attention on the nanoparticle (less than 100 nm) size range which dominates the number count in urban areas. Urban measurements of particle size distributions have tended to show a broadly similar pattern dominated by a mode centred on 20–30 nm diameter emitted by diesel engine exhaust. In this paper we report the results of measurements of particle number concentration and size distribution made in a major London park as well as on the BT Tower, 160 m aloft. These measurements taken during the REPARTEE project (Regents Park and BT Tower experiment) show a remarkable shift in particle size distributions with major losses of the smallest particle class as particles are advected away from the traffic source. In the Park, the traffic related mode at 20–30 nm diameter is much reduced with a new mode at <10 nm. Size distribution measurements also revealed higher number concentrations of sub-50 nm particles at the BT Tower during days affected by higher turbulence as determined by Doppler Lidar measurements and are indicative of loss of nanoparticles from air aged during less turbulent conditions. These results are suggestive of nanoparticle loss by evaporation, rather than coagulation processes. The results have major implications for understanding the impacts of traffic-generated particulate matter on human health.

scholarly journals The MESSy aerosol submodel MADE3 (v2.0b): description and a box model test

2014 ◽  
Vol 7 (3) ◽  
pp. 1137-1157 ◽  
Author(s):  
J. C. Kaiser ◽  
J. Hendricks ◽  
M. Righi ◽  
N. Riemer ◽  
R. A. Zaveri ◽  
...  
Keyword(s):  
Particle Size ◽  
Box Model ◽  
Aerosol Size Distribution ◽  
Sea Spray ◽  
Test Case ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Aerosol Dynamics ◽  
Coarse Mode ◽  
Made In

Abstract. We introduce MADE3 (Modal Aerosol Dynamics model for Europe, adapted for global applications, 3rd generation; version: MADE3v2.0b), an aerosol dynamics submodel for application within the MESSy framework (Modular Earth Submodel System). MADE3 builds on the predecessor aerosol submodels MADE and MADE-in. Its main new features are the explicit representation of coarse mode particle interactions both with other particles and with condensable gases, and the inclusion of hydrochloric acid (HCl) / chloride (Cl) partitioning between the gas and condensed phases. The aerosol size distribution is represented in the new submodel as a superposition of nine lognormal modes: one for fully soluble particles, one for insoluble particles, and one for mixed particles in each of three size ranges (Aitken, accumulation, and coarse mode size ranges). In order to assess the performance of MADE3 we compare it to its predecessor MADE and to the much more detailed particle-resolved aerosol model PartMC-MOSAIC in a box model simulation of an idealised marine boundary layer test case. MADE3 and MADE results are very similar, except in the coarse mode, where the aerosol is dominated by sea spray particles. Cl is reduced in MADE3 with respect to MADE due to the HCl / Cl partitioning that leads to Cl removal from the sea spray aerosol in our test case. Additionally, the aerosol nitrate concentration is higher in MADE3 due to the condensation of nitric acid on coarse mode particles. MADE3 and PartMC-MOSAIC show substantial differences in the fine particle size distributions (sizes &amp;lesssim; 2 μm) that could be relevant when simulating climate effects on a global scale. Nevertheless, the agreement between MADE3 and PartMC-MOSAIC is very good when it comes to coarse particle size distributions (sizes &amp;gtrsim; 2 μm), and also in terms of aerosol composition. Considering these results and the well-established ability of MADE in reproducing observed aerosol loadings and composition, MADE3 seems suitable for application within a global model.

scholarly journals Size-resolved particle number emissions in Beijing determined from measured particle size distributions

2020 ◽  
Author(s):  
Jenni Kontkanen ◽  
Chenjuan Deng ◽  
Yueyun Fu ◽  
Lubna Dada ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Particle Size ◽  
Air Quality ◽  
Particle Number ◽  
Aerosol Particles ◽  
Urban Environments ◽  
Integrated Assessment Model ◽  
Assessment Model ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Measured Particle

Abstract. The climate and air quality effects of aerosol particles depend on the number and size of the particles. In urban environments, a large fraction of aerosol particles originates from anthropogenic emissions. To evaluate the effects of different pollution sources on air quality, knowledge of size distributions of particle number emissions is needed. Here we introduce a novel method for determining size-resolved particle number emissions based on measured particle size distributions. We apply our method to data measured in Beijing, China, to determine the number size distribution of emitted particles in diameter range from 2 to 1000 nm. The observed particle number emissions are dominated by emissions of particles smaller than 30 nm. Our results suggest that traffic is the major source of particle number emissions with the highest emissions observed for particles around 10 nm during rush hours. At sizes below 6 nm, clustering of atmospheric vapors contributes to calculated emissions. The comparison between our calculated emissions and those estimated with an integrated assessment model GAINS shows that our method yields clearly higher particle emissions at sizes below 60 nm, but at sizes above that the two methods agree well. Overall, our method is proven to be a useful tool for gaining new knowledge of size distributions of particle number emissions in urban environments.

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