Characterization of California aerosols—II. Aerosol size distribution measurements in the Mojave Desert

Sverdrup, G.M.; Whitby, K.T.; Clark, W.A.T.

doi:10.1016/0004-6981(75)90108-0

Cited by 32 publications

(2 citation statements)

References 6 publications

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“…In the Mojave Desert, Sverdrup et al collected dust particles originating from the southern coast of the United States. These particles increased aerosol volume concentrations six times compared to a background day, which highlighted the transport of dust particles between different regions [11]. Through many measurements, Porter and Clarke found that dust particles originating from Asia that settled in Hawaii through long-range transport had different peaks in their size distributions, compared with those of longrange transported Saharan dust particles, highlighting that particles size distributions are influenced by transport time [12].…”

Section: Introductionmentioning

confidence: 94%

Dust Particle Size Distributions during Spring in Yinchuan, China

Shao

Mao

2016

Advances in Meteorology

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Dust particle size distributions in Yinchuan, China, were measured during March and April 2014, using APS-3321 sampler. The distributions were measured under different dust conditions (background, floating dust, blowing dust, and dust storm) and statistical analyses were performed. The results showed that, under different dust conditions, the instantaneous number concentrations of dust particles differed widely. For example, during blowing sand and dust storm conditions, instantaneous dust particles concentrations varied substantially, while, under floating dust conditions, concentration differences were relatively small. The average dust particles size distributions were unimodal under all dust conditions, but the average surface area and mass size distributions were all bimodal. These distributions had peaks in different locations under different dust conditions. Under different dust conditions, wind speed and humidity were very important factors for particles size distributions. With increasing wind speed and decreasing humidity, fine particles were dominant in the atmosphere and the number and mass distributions of the coarse particles were indicative of long-range transport from surrounding deserts. Different dust conditions had different influences on PM1, PM2.5, and PM10concentrations.

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Section: Introductionmentioning

confidence: 94%

Dust Particle Size Distributions during Spring in Yinchuan, China

Shao

Mao

2016

Advances in Meteorology

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“…Observed size distributions for mineral dust are highly variable, depending on the source region of dust particles, the measurement period and location, and the associated meteorological conditions. Some values of D gN for single‐mode fits to observed size distributions are 0.22–1.76 μm for Asian dust [ Arao and Ishizaka , 1986; Gomes and Gillette , 1993; Nishikawa et al , 1991; Peterson , 1968; Sviridenkov et al , 1993], 0.34–1.62 μm for African dust [ Gillies et al , 1996; Gomes and Gillette , 1993; Jaenicke and Junge , 1967; Savoie and Prospero , 1976], and 0.59–0.88 μm for North American dust [ Sverdrup et al , 1975; Patterson and Gillette , 1977]. The range of D gN values for multimode fits is even greater [ d'Almeida , 1987; Lei et al , 1993].…”

Section: Model Descriptionmentioning

confidence: 99%

MIRAGE: Model description and evaluation of aerosols and trace gases

et al. 2004

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[1] The Model for Integrated Research on Atmospheric Global Exchanges (MIRAGE) modeling system, designed to study the impacts of anthropogenic aerosols on the global environment, is described. MIRAGE consists of a chemical transport model coupled online with a global climate model. The chemical transport model simulates trace gases, aerosol number, and aerosol chemical component mass (sulfate, methane sulfonic acid (MSA), organic matter, black carbon (BC), sea salt, and mineral dust) for four aerosol modes (Aitken, accumulation, coarse sea salt, and coarse mineral dust) using the modal aerosol dynamics approach. Cloud-phase and interstitial aerosol are predicted separately. The climate model, based on Community Climate Model, Version 2 (CCM2), has physically based treatments of aerosol direct and indirect forcing. Stratiform cloud water and droplet number are simulated using a bulk microphysics parameterization that includes aerosol activation. Aerosol and trace gas species simulated by MIRAGE are presented and evaluated using surface and aircraft measurements. Surface-level SO 2 in North American and European source regions is higher than observed. SO 2 above the boundary layer is in better agreement with observations, and surface-level SO 2 at marine locations is somewhat lower than observed. Comparison with other models suggests insufficient SO 2 dry deposition; increasing the deposition velocity improves simulated SO 2 . Surface-level sulfate in North American and European source regions is in good agreement with observations, although the seasonal cycle in Europe is stronger than observed. Surface-level sulfate at high-latitude and marine locations, and sulfate above the boundary layer, are higher than observed. This is attributed primarily to insufficient wet removal; increasing the wet removal improves simulated sulfate at remote locations and aloft. Because of the high sulfate bias, radiative forcing estimates for anthropogenic sulfur given in 2001 by S. J. Ghan and colleagues are probably too high. Surface-level dimethyl sulfide (DMS) is $40% higher than observed, and the seasonal cycle shows too much DMS in local winter, partially caused by neglect of oxidation by NO 3 . Surface-level MSA at marine locations is $80% higher than observed, also attributed to insufficient wet removal. Surface-level BC is $50% lower than observed in the United States and $40% lower than observed globally. Treating BC as initially hydrophobic would lessen this bias. Surface-level organic matter is lower than observed in the United States, similar to BC, but shows no bias in the global comparison. Surface-level sea salt concentrations are $30% lower than observed, partly caused by low temporal variance of the model's 10 m wind speeds. Submicrometer sea salt is strongly underestimated by the emissions parameterization. Dust concentrations are within a factor of 3 at most sites but tend to be lower than observed, primarily because of neglect of very large particles and underestimation of emissions and vertical transport under ...

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On the relevance of air pollution measurements of aliphatic and polyaromatic hydrocarbons in ambient particulate matter

Vaeck

Broddin

Cauwenberghe

1980

Biol. Mass Spectrom.

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During the last decade, a considerable amount of information has been gathered on the organic composition of aerosols, mostly sampled by Hi-Vol filtration, and analysed by gas chromatography or gas chromatography mass spectrometry. From our research, it appears that care should be taken in the use of such data for the evaluation of health hazards, resulting from air pollution. The following facts must be considered.(1) The conventional Hi-Vol filtration sampling technique can be subject to several sampling artifacts, such as volatilization from and chemical reaction on the filter. Indeed, a series of compounds of intermediate volatility has been shown to evaporate from particles on the filter, when exposed to large air volumes. Low molecular weight compounds are predominant in the gas phase, and high molecular weight ones in the particulate phase.Furthermore, some pollutants on collected particles can react with molecular or radical species, present in the atmosphere: e.g. the carcinogen benzo(a)pyrene can be degraded very rapidly by traces of ozone to highly polar compounds. (2) Besides pollutants of anthropogenic origin, natural sources may also contribute to the aerosol burden. Thus, the presence of the higher odd carbon numbered n-alkanes reflects the contribution from vegetation (plant waxes). The possible synergistic activity of these compounds in combination with carcinogens, justifies the monitoring of these contaminants in aerosols. (3) Since the retention of particles in the respiratory tract strongly depends on particle size, measurements of total pollutant concentrations have to be supplemented with particle size distribution data. The analysis of several size fractionated samples, taken at suburban as well as at remote rural and sea shore sites, allows the evaluation of the dilution of particulate organics and of the differences in particle size distributions in the background areas. Most pollutants are almost exclusively distributed over the respirable particle size range (below 3 pm) and any observed distribution shifts remain within this range. In conclusion, a realistic estimate is presentedtof the fractions deposited in and extracted by the tissues of the respiratory tract. These are directly responsible for the health hazards, associated with breathing aerosol particles. It follows that a nearly constant fraction of a given pollutant, enters the bloodstream, irrespective of the sampling site, and thus health hazards remain closely related to the total Concentration levels.

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Characterization of California aerosols—II. Aerosol size distribution measurements in the Mojave Desert

Cited by 32 publications

References 6 publications

Dust Particle Size Distributions during Spring in Yinchuan, China

Dust Particle Size Distributions during Spring in Yinchuan, China

MIRAGE: Model description and evaluation of aerosols and trace gases

On the relevance of air pollution measurements of aliphatic and polyaromatic hydrocarbons in ambient particulate matter

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