Geophysical applicability of aerosol size distribution measurements using cascade impactors and proton induced X-ray emission

1976 ◽  
Vol 10 (8) ◽  
pp. 571-576 ◽  
Author(s):  
R.E. Van Grieken ◽  
T.B. Johansson ◽  
K.R. Akselsson ◽  
J.W. Winchester ◽  
J.W. Nelson ◽  
...  
Keyword(s):  
Size Distribution ◽  
Aerosol Size Distribution ◽  
X Ray ◽  
Cascade Impactors

scholarly journals Evaluating model parameterizations of submicron aerosol scattering and absorption with in situ data from ARCTAS 2008

2016 ◽  
Vol 16 (14) ◽  
pp. 9435-9455 ◽  
Author(s):  
Matthew J. Alvarado ◽  
Chantelle R. Lonsdale ◽  
Helen L. Macintyre ◽  
Huisheng Bian ◽  
Mian Chin ◽  
...  
Keyword(s):  
Optical Properties ◽  
Size Distribution ◽  
Aerosol Size Distribution ◽  
Visible Radiation ◽  
Submicron Aerosol ◽  
In Situ Data ◽  
Aerosol Absorption ◽  
Aerosol Scattering ◽  
The Impact

Abstract. Accurate modeling of the scattering and absorption of ultraviolet and visible radiation by aerosols is essential for accurate simulations of atmospheric chemistry and climate. Closure studies using in situ measurements of aerosol scattering and absorption can be used to evaluate and improve models of aerosol optical properties without interference from model errors in aerosol emissions, transport, chemistry, or deposition rates. Here we evaluate the ability of four externally mixed, fixed size distribution parameterizations used in global models to simulate submicron aerosol scattering and absorption at three wavelengths using in situ data gathered during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) campaign. The four models are the NASA Global Modeling Initiative (GMI) Combo model, GEOS-Chem v9-02, the baseline configuration of a version of GEOS-Chem with online radiative transfer calculations (called GC-RT), and the Optical Properties of Aerosol and Clouds (OPAC v3.1) package. We also use the ARCTAS data to perform the first evaluation of the ability of the Aerosol Simulation Program (ASP v2.1) to simulate submicron aerosol scattering and absorption when in situ data on the aerosol size distribution are used, and examine the impact of different mixing rules for black carbon (BC) on the results. We find that the GMI model tends to overestimate submicron scattering and absorption at shorter wavelengths by 10–23 %, and that GMI has smaller absolute mean biases for submicron absorption than OPAC v3.1, GEOS-Chem v9-02, or GC-RT. However, the changes to the density and refractive index of BC in GC-RT improve the simulation of submicron aerosol absorption at all wavelengths relative to GEOS-Chem v9-02. Adding a variable size distribution, as in ASP v2.1, improves model performance for scattering but not for absorption, likely due to the assumption in ASP v2.1 that BC is present at a constant mass fraction throughout the aerosol size distribution. Using a core-shell mixing rule in ASP overestimates aerosol absorption, especially for the fresh biomass burning aerosol measured in ARCTAS-B, suggesting the need for modeling the time-varying mixing states of aerosols in future versions of ASP.

scholarly journals X-ray diffraction study of crystallite size-distribution and strain in carbon blacks

2000 ◽  
Vol 661 ◽  
Author(s):  
T. Ungár ◽  
J. Gubicza ◽  
G. Ribárik ◽  
T. W. Zerda
Keyword(s):  
Crystallite Size ◽  
Size Distribution ◽  
Fourier Coefficients ◽  
Shape Anisotropy ◽  
X Ray Diffraction ◽  
Strain Anisotropy ◽  
X Ray ◽  
Carbon Blacks ◽  
Size Profile ◽  
Crystallite Shape

ABSTRACTThe crystallite size and size-distribution in carbon blacks in the presence of strain are determined by recently developed procedure of X-ray diffraction peak profile analysis. The Fourier coefficients of the measured physical profiles are fitted by Fourier coefficients of well established ab initio functions of size and strain peak profiles. Strain anisotropy is accounted for by expressing the mean square strain in terms of average dislocation contrast factors. Crystallite shape anisotropy is modelled by ellipsoids incorporated into the size profile function. To make the fitting procedure faster, the Fourier transform of the size profile is given as an analitical function. The method is applied to carbon blacks treated at different preassures and temperatures. The microstructure is characterised in terms of crystallite size distribution, dislocation density, and crystallite shape anisotropy.

Evolution of the Pore Size Distribution in Final-Stage Sintering of Alumina Measured by Small-Angle X-ray Scattering

1991 ◽  
Vol 74 (10) ◽  
pp. 2538-2546 ◽  
Author(s):  
Susan Krueger ◽  
Gabrielle G. Long ◽  
David R. Black ◽  
Dennis Minor ◽  
Pete R. Jemian ◽  
...  
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Small Angle ◽  
Final Stage ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Faucet aerator design influences aerosol size distribution and microbial contamination level

2021 ◽  
Vol 775 ◽  
pp. 145690
Author(s):  
Marie-Ève Benoit ◽  
Michèle Prévost ◽  
Antonella Succar ◽  
Dominique Charron ◽  
Eric Déziel ◽  
...  
Keyword(s):  
Size Distribution ◽  
Microbial Contamination ◽  
Aerosol Size Distribution ◽  
Contamination Level

X-ray fluorescence spectrometry for rapid screening of particle size in soils

2021 ◽  
Author(s):  
Maame Croffie ◽  
Paul N. Williams ◽  
Owen Fenton ◽  
Anna Fenelon ◽  
Karen Daly
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Texture ◽  
Particle Size Analysis ◽  
Parent Material ◽  
Fluorescence Spectrometry ◽  
Rapid Screening ◽  
Size Analysis ◽  
X Ray

<p>Soil texture is an essential factor for effective land management in agricultural production. Knowledge of soil texture and particle size at field scale can aid with on-going soil management decisions. Standard soil physical and gravimetric methods for particle size analysis are time-consuming and X-ray fluorescence spectrometry (XRF) provides a rapid and cost-effective alternative. The objective of this study was to explore the use of XRF as a predictor for particle size. An extensive archive of Irish soils with particle size and soil texture data was used to select samples for XRF analysis. Regression and correlation analyses on XRF determined results showed that the relationship between Rb and % clay varied with soil type and was dependent on the parent material. There was a strong relationship (R > 0.62, R<sup>2</sup>>0.30, p<0.05) between Rb and clay for soils originating from bedrock such as limestones and slate. Contrastingly, no significant relationship (R<0.03, R<sup>2</sup>=0.00, p>0.05) exists between Rb and % clay for soils originating from granite and gneiss. Furthermore, there was a significant negative correlation (p<0.05) between Rb and % sand. The XRF is a useful technique for rough screening of particle size distribution in soils originating from certain parent materials. Thus, this may contribute to the rapid prediction of soil texture based on knowledge of the particle size distribution.</p><p> </p>

scholarly journals Combining airborne in situ and ground-based lidar measurements for attribution of aerosol layers

2018 ◽  
Author(s):  
Anna Nikandrova ◽  
Ksenia Tabakova ◽  
Antti Manninen ◽  
Riikka Väänänen ◽  
Tuukka Petäjä ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Size Distribution ◽  
Aerosol Size Distribution ◽  
Long Range Transport ◽  
Back Trajectories ◽  
Clear Sky ◽  
Temporal And Spatial Variability ◽  
Range Transport ◽  
Temporal And Spatial

Abstract. Understanding the distribution of aerosol layers is important for determining long range transport and aerosol radiative forcing. In this study we combine airborne in situ measurements of aerosol with data obtained by a ground-based High Spectral Resolution Lidar (HSRL) and radiosonde profiles to investigate the temporal and vertical variability of aerosol properties in the lower troposphere. The HSRL was deployed in Hyytiälä, Southern Finland, from January to September 2014 as a part of the US DoE ARM (Atmospheric Radiation Measurement) mobile facility during the BAECC (Biogenic Aerosols – Effects on Cloud and Climate) Campaign. Two flight campaigns took place in April and August 2014 with instruments measuring the aerosol size distribution from 10 nm to 10 µm at altitudes up to 3800 m. Two case studies from the flight campaigns, when several aerosol layers were identified, were selected for further investigation: one clear sky case, and one partly cloudy case. During the clear sky case, turbulent mixing ensured low temporal and spatial variability in the measured aerosol size distribution in the boundary layer whereas mixing was not as homogeneous in the boundary layer during the partly cloudy case. The elevated layers exhibited greater temporal and spatial variability in aerosol size distribution, indicating a lack of mixing. New particle formation was observed in the boundary layer during the clear sky case, and nucleation mode particles were also seen in the elevated layers that were not mixing with the boundary layer. Interpreting local measurements of elevated layers in terms of long-range transport can be achieved using back trajectories from Lagrangian models, but care should be taken in selecting appropriate arrival heights, since the modelled and observed layer heights did not always coincide. We conclude that higher confidence in attributing elevated aerosol layers with their air mass origin is attained when back trajectories are combined with lidar and radiosonde profiles.

scholarly journals A global off-line model of size-resolved aerosol microphysics: I. Model development and prediction of aerosol properties

2005 ◽  
Vol 5 (8) ◽  
pp. 2227-2252 ◽  
Author(s):  
D. V. Spracklen ◽  
K. J. Pringle ◽  
K. S. Carslaw ◽  
M. P. Chipperfield ◽  
G. W. Mann
Keyword(s):  
Boundary Layer ◽  
Sulfuric Acid ◽  
Size Distribution ◽  
Marine Boundary Layer ◽  
Transport Model ◽  
Model Development ◽  
Aerosol Size Distribution ◽  
Chemical Transport Model ◽  
Cloud Processing ◽  
Nucleation Mechanisms

Abstract. A GLObal Model of Aerosol Processes (GLOMAP) has been developed as an extension to the TOMCAT 3-D Eulerian off-line chemical transport model. GLOMAP simulates the evolution of the global aerosol size distribution using a sectional two-moment scheme and includes the processes of aerosol nucleation, condensation, growth, coagulation, wet and dry deposition and cloud processing. We describe the results of a global simulation of sulfuric acid and sea spray aerosol. The model captures features of the aerosol size distribution that are well established from observations in the marine boundary layer and free troposphere. Modelled condensation nuclei (CN>3nm) vary between about 250–500 cm-3 in remote marine boundary layer regions and are generally in good agreement with observations. Modelled continental CN concentrations are lower than observed, which may be due to lack of some primary aerosol sources or the neglect of nucleation mechanisms other than binary homogeneous nucleation of sulfuric acid-water particles. Remote marine CN concentrations increase to around 2000–10 000 cm

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