A Laboratory Comparison of Real-Time Measurement Methods for 10–100-nm Particle Size Distributions

Hornsby, K. E.; Pryor, S. C.

doi:10.1080/02786826.2014.901488

Cited by 12 publications

(13 citation statements)

References 36 publications

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“…For particles in the 10-100 nm size range, Hornsby and Pryor (2014) report an agreement between several TSI SMPS systems and a TSI FMPS system (fast mobility particle sizer) of within ±30 % for particle number concentration and of within ±7.5 % for geometric mean diameter (D pg ). Those values can be considered a lower limit for the uncertainties in long-term field measurements, especially at locations with difficult maintenance conditions.…”

Section: Particle Number Size Distribution Measurementsmentioning

confidence: 86%

Multi-year statistical and modeling analysis of submicrometer aerosol number size distributions at a rain forest site in Amazonia

et al. 2018

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Abstract. The Amazon Basin is a unique region to study atmospheric aerosols, given their relevance for the regional hydrological cycle and the large uncertainty of their sources. Multi-year datasets are crucial when contrasting periods of natural conditions and periods influenced by anthropogenic emissions. In the wet season, biogenic sources and processes prevail, and the Amazonian atmospheric composition resembles preindustrial conditions. In the dry season, the basin is influenced by widespread biomass burning emissions. This work reports multi-year observations of high time resolution submicrometer (10-600 nm) particle number size distributions at a rain forest site in Amazonia (TT34 tower, 60 km NW from Manaus city), between 2008 and 2010 and 2012 and 2014. The median particle number concentration was 403 cm −3 in the wet season and 1254 cm −3 in the dry season. The Aitken mode (∼ 30-100 nm in diameter) was prominent during the wet season, while the accumulation mode (∼ 100-600 nm in diameter) dominated the particle size spectra during the dry season. Cluster analysis identified groups of aerosol number size distributions influenced by convective downdrafts, nucleation events and fresh biomass burning emissions. New particle formation and subsequent growth was rarely observed during the 749 days of observations, similar to previous observations in the Amazon Basin. A stationary 1-D column model (ADCHEMAerosol Dynamics, gas and particle phase CHEMistry and radiative transfer model) was used to assess the importance of the processes behind the observed diurnal particle size distribution trends. Three major particle source types are required in the model to reproduce the observations: (i) a surface source of particles in the evening, possibly related to primary biological emissions; (ii) entrainment of accumulation mode aerosols in the morning; and (iii) convective downdrafts transporting Aitken mode particles into the boundary layer mostly during the afternoon. The latter process has the largest influence on the modeled particle number size distributions. However, convective downdrafts are often associated with rain and, thus, act as both a source of Aitken mode particles and a sink of accumulation mode particles, causing a net reduction in the median total particle number concentrations in the surface layer. Our study shows that the combination of the three mentioned particle sources is essential to sustain particle number concentrations in Amazonia.

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Section: Particle Number Size Distribution Measurementsmentioning

confidence: 86%

Multi-year statistical and modeling analysis of submicrometer aerosol number size distributions at a rain forest site in Amazonia

et al. 2018

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“…For example, although inter-comparison of the FMPS and SMPS data indicate Pearson correlation of hourly average total particle number concentration > 0.9, N nuc from the SMPS was systematically higher (Pryor et al, 2010), potentially leading to higher estimated J 6 . Lab inter-comparison of these instruments also indicate that, to a degree that is a function of composition, the SMPS exhibits higher modal peak concentrations and lower modal diameter than the FMPS (Hornsby and Pryor, 2014). Thus, the data sets from the two experimental campaigns are treated separately.…”

Section: Event Classification Growth Rates Formation Rates and Surmentioning

confidence: 99%

Dynamic and chemical controls on new particle formation occurrence and characteristics from in situ and satellite-based measurements

Sullivan

Pryor

2016

Atmospheric Environment

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We analyze the association between satellite-based measurements of chemical conditions (sulfur dioxide (SO 2), nitrogen dioxide (NO 2), and formaldehyde (HCHO) concentrations), insolation (UV), and aerosol particle properties (aerosol optical depth (AOD) and Ångström exponent (AE)); and the occurrence of new particle formation (NPF), formation rates (J 6), growth rates (GR), and survival probabilities (SP) using particle size distribution measurements taken during two extended field campaigns at a forested location in southern Indiana. When conditionally sampled by event occurrence and non-occurrence the satellite-derived parameters exhibit significant differences and also show some degree of skill in predicting NPF though logistic regression analysis. During leaf-on measurement periods, NPF occurrence exhibits strong seasonality (NPF is more frequent in spring vs. summer) and is associated with a low condensational sink, while leaf-off NPF occurrence is associated with high near-surface UV receipt. Multiple linear regression equations of J 6 , GR, and SP using the chemical conditions as predictors exhibit some significant r 2 values (p < 0.1), but are relatively unstable and many of the regression coefficients do not differ significantly from zero.

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“…The study concluded that the agreement between FMPS and SMPS is linked to the particle size and morphology. Hornsby and Pryor (2014) compared four SMPS systems and one FMPS for particles with GMDs between 10 nm and 100 nm. They found low deviation for the FMPSs from the GMD ( §7.5%) as measured by the SMPS systems.…”

Section: Introductionmentioning

confidence: 99%

Limitations in the Use of Unipolar Charging for Electrical Mobility Sizing Instruments: A Study of the Fast Mobility Particle Sizer

Levin

Gudmundsson

Pagels

et al. 2015

Aerosol Science and Technology

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A comparison between three different types of particle sizing instruments (fast mobility particle sizer, FMPS; electrical low pressure impactor, ELPI; and scanning mobility particle sizer, SMPS) and one condensation particle counter (CPC) was made to compare instrument response in terms of size distributions and number concentration. Spherical oil droplets in 39 different sizes, with geometric mean diameter (GMD) ranging from 50 nm to 820 nm, were used as test particles. Furthermore, a characterization of the FMPS unipolar charger behavior was made to analyze the measured size distributions and number concentrations. The results show that all three sizing-instruments agree well for particle sizes below 200 nm, both in terms of size and number concentration, but the FMPS deviates clearly when particle sizes exceed 200 nm. Above this, the FMPS underestimates the particle size throughout the remainder of the size range, with an apparent upper limit for GMD of 300 nm. It also estimates a higher particle number concentration as compared to the other instruments. Analysis of the 22 FMPS electrometer currents and calculation of average number of charges per particle show a diameter dependence of response of d 1:21 p for the FMPS unipolar charger. The resulting calculated electrical mobility showed a minimum in mobility for spherical particles at 577 nm, which indicates an interfering range of particles above the measurement range, but below the cut-off of the inlet pre-separator (1 mm). The study concludes that particle distributions with a true GMD above 200 nm cannot be measured reliably with the FMPS.

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A Laboratory Comparison of Real-Time Measurement Methods for 10–100-nm Particle Size Distributions

Cited by 12 publications

References 36 publications

Multi-year statistical and modeling analysis of submicrometer aerosol number size distributions at a rain forest site in Amazonia

Multi-year statistical and modeling analysis of submicrometer aerosol number size distributions at a rain forest site in Amazonia

Dynamic and chemical controls on new particle formation occurrence and characteristics from in situ and satellite-based measurements

Limitations in the Use of Unipolar Charging for Electrical Mobility Sizing Instruments: A Study of the Fast Mobility Particle Sizer

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