Number-size distributions of free tropospheric aerosol particles at Mt. Norikura, Japan: Effects of precipitation and air mass transportation pathways

Inhalers are hand-held devices which are used for administration of therapeutic aerosols via inhalation. Nebulizers are larger devices serving for home and hospital care using inhaled medication. This contribution describes the basic principles of dispersion of aerosol particles used in various types of inhalers and nebulizers, and lists the basic physical mechanisms contributing to the deposition of inhaled particles in the human airways. The second part of this article presents experimental setup, methodology and preliminary results of particle size distributions produced by several selected inhalers and nebulizers.

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Confocal Microprobe Raman Imaging of Urban Tropospheric Aerosol Particles

Environmental Science & Technology ◽

10.1021/es051294x ◽

2006 ◽

Vol 40 (4) ◽

pp. 1300-1306 ◽

Cited By ~ 53

Author(s):

Yann Batonneau ◽

Sophie Sobanska ◽

Jacky Laureyns ◽

Claude Bremard

Keyword(s):

Aerosol Particles ◽

Raman Imaging ◽

Tropospheric Aerosol

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Tropospheric aerosol scattering and absorption over Central Europe: a closure study for the dry particle state

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-27811-2013 ◽

2013 ◽

Vol 13 (10) ◽

pp. 27811-27854 ◽

Cited By ~ 1

Author(s):

N. Ma ◽

W. Birmili ◽

T. Müller ◽

T. Tuch ◽

Y. F. Cheng ◽

...

Keyword(s):

Optical Properties ◽

Direct Measurement ◽

Radiative Forcing ◽

Control Measure ◽

Atmospheric Stability ◽

Scattering Coefficient ◽

Particle State ◽

Air Mass ◽

Aerosol Scattering ◽

Tropospheric Aerosol

Abstract. This work analyses optical properties of the dry tropospheric aerosol measured at the regional GAW observation site Melpitz in East Germany. For a continuous observation period between 2007 and 2010, we provide representative values of the dry-state scattering coefficient, the hemispheric backscattering coefficient, the absorption coefficient, single scattering albedo, and the Ångström exponent. Besides the direct measurement, the aerosol scattering coefficient was alternatively computed from experimental particle number size distributions using a Mie code. Within pre-defined limits, a closure could be achieved with the direct measurement. The achievement of closure implies that such calculations can be used as a high-level quality control measure for data sets involving multiple instrumentation. All dry optical properties showed significant annual variations, which were attributed to corresponding variations in the regional emission fluxes, the intensity of secondary particle formation, and the mixed layer height. Air mass classification showed that atmospheric stability is a major factor influencing the dry aerosol properties at the GAW station. In the cold season, temperature inversions limit the volume available for atmospheric mixing, so that the aerosol optical properties near the ground proved quite sensitive to the geographical origin of the air mass. In the warm season, when the atmosphere is usually well-mixed during day-time, considerably less variability was observed for the optical properties between different air masses. This work provides, on the basis of quality-checked in-situ measurements, a first step towards a climatological assessment of direct aerosol radiative forcing in the region under study.

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-11329-2020 ◽

2020 ◽

Vol 20 (19) ◽

pp. 11329-11348 ◽

Cited By ~ 2

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.

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In situ observations of aerosol particles remaining from evaporated cirrus crystals: Comparing clean and polluted air masses

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-2-1599-2002 ◽

2002 ◽

Vol 2 (5) ◽

pp. 1599-1633 ◽

Cited By ~ 5

Author(s):

M. Seifert ◽

J. Ström ◽

R. Krejci ◽

A. Minikin ◽

A. Petzold ◽

...

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Aerosol Particles ◽

Pollution Level ◽

Size Distributions ◽

Number Density ◽

Particle Volume ◽

The North ◽

In Situ Observations

Abstract. In situ observations of aerosol particles contained in cirrus crystals are presented and compared to interstitial aerosol size distributions (non-activated particles in between the cirrus crystals). The observations were conducted in cirrus clouds in the Southern and Northern Hemisphere mid-latitudes during the INCA project. The first campaign in March and April 2000 was performed from Punta Arenas, Chile (54° S) in pristine air. The second campaign in September and October 2000 was performed from Prestwick, Scotland (53° N) in the vicinity of the North Atlantic flight corridor. Size distribution measurements of crystal residuals (particles remaining after evaporation of the crystals) show that small aerosol particles (Dp < 0.1µm) dominate the number density of residuals. The crystal residual size distributions were significantly different in the two campaigns. On average the residual size distributions were shifted towards larger sizes in the Southern Hemisphere. For a given integral residual number density, the calculated particle volume was on average three times larger in the Southern Hemisphere. This may be of significance to the vertical redistribution of aerosol mass by clouds in the tropopause region. In both campaigns the mean residual size increased with increasing crystal number density. The observations of ambient aerosol particles were consistent with the expected higher pollution level in the Northern Hemisphere. The fraction of residual particles only contributes to approximately a percent or less of the total number of particles, which is the sum of the residual and interstitial particles.

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Temporal variation of water-soluble ions of free tropospheric aerosol particles over central Japan

Tellus B ◽

10.1111/j.1600-0889.2007.00296.x ◽

2007 ◽

Vol 59 (4) ◽

pp. 742-754 ◽

Cited By ~ 12

Author(s):

K. Osada ◽

M. Kido ◽

C. Nishita ◽

K. Matsunaga ◽

Y. Iwasaka ◽

...

Keyword(s):

Temporal Variation ◽

Aerosol Particles ◽

Water Soluble ◽

Central Japan ◽

Soluble Ions ◽

Tropospheric Aerosol ◽

Water Soluble Ions

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The rain induced gamma-radiation dose rate enhancement at Järvselja SMEAR station

10.5194/egusphere-egu21-15644 ◽

2021 ◽

Author(s):

Urmas Hõrrak ◽

Xuemeng Chen ◽

Kristo Hõrrak ◽

Uko Rand ◽

Kaupo Komsaare ◽

...

Keyword(s):

Radiation Dose ◽

Gamma Radiation ◽

Dose Rate ◽

Atmospheric Aerosol ◽

Aerosol Particles ◽

Aerosol Formation ◽

Radiation Dose Rate ◽

Air Mass ◽

Rate Enhancement ◽

Gamma Radiation Dose

The SMEAR Estonia station (58.277663 N, 27.308266 E, 36 m a.s.l.) was established in south-east of Estonia at the J&#228;rvselja Experimental Forestry in 2012 to investigate the atmosphere-biosphere interactions and atmospheric aerosol formation and growth.In summer 2019, the gamma-radiation monitor GammaTRACER XL2-3 (Saphymo GmbH) was set up at J&#228;rvselja station and the rain sensor DRD11A (Vaisala Oyj) in autumn 2019. These devices enable to measure the gamma-radiation dose rate and precipitation intensity, which affect the ionization rate of atmospheric air close to ground, with high accuracy and time resolution, and complement our measurement system of atmospheric ions and aerosol particles.The gamma-radiation dose rate measurements at about 1.2 m above the ground reveled on relatively steady background about 70 nSv/h occasional events with increase up to about 110 nSv/h, which correlated well with rainfall intensity. Commonly such events last 3-4 hours, but in specific meteorological situation with continuous long-lasting rain and air mass movement from southerly directions the effect can last 2-3 days, resulting in gradual increase in gamma-radiation dose rate level during about 24 h.Such a phenomenon is known to occur due to wet deposition of radioactive aerosol particles during rain, namely due to the radon (222 Rn) short-lived daughter progeny products (Po-218, Pb-214, Bi-214) attached to atmospheric aerosol particles. The radon (222 Rn) daughter progeny involvement is confirmed by simultaneous gamma-spectrometric measurements with SARA AGS711F (Envinet GmbH) at T&#245;ravere station (58&#176; 15' 52,9" N, 26&#176; 27' 42,1", 72 m), located about 50.3 km west from the J&#228;rvselja SMEAR station. The gamma dose rates showed very similar temporal behavior when both stations were affected by the same air mass with precipitation zone passing over the stations.To our best knowledge, the details of rain-induced enhancement of gamma-radiation dose rate and atmospheric processes behind the phenomenon are not well known and are worth future investigations. The events of rain induced gamma-radiation dose rate enhancement at J&#228;rvselja SMEAR and T&#245;ravere station are analyzed and discussed in more detail in the presentation and the spatial representativity of the phenomenon is estimated based on the gamma-radiation monitoring network data of Estonian Early Warning System.

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Aerosol properties and their influences on low warm clouds during the Two-Column Aerosol Project

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-9515-2019 ◽

2019 ◽

Vol 19 (14) ◽

pp. 9515-9529 ◽

Cited By ~ 4

Author(s):

Jianjun Liu ◽

Zhanqing Li

Keyword(s):

Optical Depth ◽

Aerosol Particles ◽

Large Contribution ◽

Loading Conditions ◽

Liquid Water Path ◽

Air Mass ◽

Aerosol Loading ◽

Cloud Properties ◽

Stable Conditions ◽

Cloud Development

Abstract. Twelve months of measurements collected during the Two-Column Aerosol Project field campaign at Cape Cod, Massachusetts, which started in the summer of 2012, were used to investigate aerosol physical, optical, and chemical properties and their influences on the dependence of cloud development on thermodynamic (i.e., lower tropospheric stability, LTS) conditions. Relationships between aerosol loading and cloud properties under different dominant air-mass conditions and the magnitude of the first indirect effect (FIE), as well as the sensitivity of the FIE to different aerosol compositions, are examined. The seasonal variation in aerosol number concentration (Na) was not consistent with variations in aerosol optical properties (i.e., scattering coefficient, σs, and columnar aerosol optical depth). Organics were found to have a large contribution to small particle sizes. This contribution decreased during the particle growth period. Under low-aerosol-loading conditions, the liquid water path (LWP) and droplet effective radius (DER) significantly increased with increasing LTS, but, under high-aerosol-loading conditions, LWP and DER changed little, indicating that aerosols significantly weakened the dependence of cloud development on LTS. The reduction in LWP and DER from low- to high-aerosol-loading conditions was greater in stable environments, suggesting that clouds under stable conditions are more susceptible to aerosol perturbations than those under more unstable conditions. High aerosol loading weakened the increase in DER as LWP increased and strengthened the increase in cloud optical depth (COD) with increasing LWP, resulting in changes in the interdependence of cloud properties. Under both continental and marine air-mass conditions, high aerosol loading can significantly increase COD and decrease LWP and DER, narrowing their distributions. Magnitudes of the FIE estimated under continental air-mass conditions ranged from 0.07±0.03 to 0.26±0.09 with a mean value of 0.16±0.03 and showed an increasing trend as LWP increased. The calculated FIE values for aerosols with a low fraction of organics are greater than those for aerosols with a high fraction of organics. This implies that clouds over regions dominated by aerosol particles containing mostly inorganics are more susceptible to aerosol perturbations, resulting in larger climate forcing, than clouds over regions dominated by organic aerosol particles.

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