Diffuse reflectance and diffuse transmission measurements of aerosol absorption at the First International Workshop on light absorption by aerosol particles

1982 ◽  
Vol 21 (3) ◽  
pp. 387 ◽  
Author(s):  
E. M. Patterson ◽  
B. T. Marshall
Keyword(s):  
Light Absorption ◽  
Diffuse Reflectance ◽  
International Workshop ◽  
Aerosol Particles ◽  
Diffuse Transmission ◽  
Aerosol Absorption ◽  
Transmission Measurements

Comparison of Two Filter-Based Reflectance Methods to Measure the Light Absorption by Atmospheric Aerosols

2014 ◽  
Vol 31 (4) ◽  
pp. 923-929 ◽  
Author(s):  
Rudra Aryal ◽  
Paul Terman ◽  
Kenneth J. Voss
Keyword(s):  
Absorption Coefficient ◽  
Atmospheric Aerosols ◽  
Light Absorption ◽  
Aerosol Particles ◽  
Sampling Scheme ◽  
Sampling Area ◽  
Aerosol Absorption ◽  
Light Absorption Coefficient ◽  
M Theory ◽  
Full Day

Abstract Two reflectance techniques, based on Kubelka–Munk (K-M) theory and on the Beer–Lambert (B-L) law, were used to measure the absorption coefficient of aerosol particles collected on a filter. The two methods agreed, with the B-L technique being higher than the K-M method by a factor of 1.10, but with a correlation, r2, between the two methods of 0.99. The aerosol absorption Ångström exponents (AAE) between the two methods also agreed within 0.4 and were in the range of measurements reported in the literature with other techniques. The precision of the two methods depends on the volume of air sampled, but a typical sampling scheme (100 L min−1, 10 cm2 sampling area, full day of sampling) results in a precision in the measurement of the aerosol light absorption coefficient of 0.05 Mm−1.

First International Workshop on Light Absorption by Aerosol Particles: Background, Activities, and Preliminary Results, 28 July–8 August 1980 Ft. Collins, Colo.

1981 ◽  
Vol 62 (9) ◽  
pp. 1321-1327 ◽  
Author(s):  
Hermann E. Gerber ◽  
Edward E. Hindman
Keyword(s):  
Light Absorption ◽  
Atmospheric Aerosol ◽  
International Workshop ◽  
Aerosol Particles ◽  
Measurement Techniques ◽  
State University ◽  
Absorption Properties ◽  
Colorado State University ◽  
Preliminary Results ◽  
Atmospheric Aerosol Particles

The amount of light absorbed by aerosol particles has not been determined with certainty because errors in measurement techniques have been difficult to quantify. To improve this situation, a workshop was conducted to establish experimentally the errors for the various techniques. The workshop was held between 28 July and 8 August 1980 at the Cloud Simulation and Aerosol Laboratory at Colorado State University. Preliminary results show that, for the same well-characterized aerosol particles, substantial differences exist between results from the various techniques. These differences can explain a fraction of the variations reported for the light absorption properties of similar types of atmospheric aerosol particles.

Light absorption by aerosol particles: First International Workshop

1982 ◽  
Vol 21 (3) ◽  
pp. 370 ◽  
Author(s):  
Hermann E. Gerber ◽  
Edward E. Hindman
Keyword(s):  
Light Absorption ◽  
International Workshop ◽  
Aerosol Particles

scholarly journals Aerosol Light Absorption at 1064 nm: Pollution Sources, Meteorological Parameters and Gas Pollutants in Qingdao Coastal Area, China

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1553
Author(s):  
Jie Chen ◽  
Wenyue Zhu ◽  
Qiang Liu ◽  
Xianmei Qian ◽  
Xuebin Li ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Light Absorption ◽  
Aerosol Particles ◽  
Anthropogenic Pollution ◽  
Atmospheric Environment ◽  
Air Masses ◽  
Aerosol Absorption ◽  
Coastal Cities ◽  
Sampling Campaign ◽  
Aerosol Sources

A two-month sampling campaign was carried out from 1 November to 30 December 2019, to investigate the light absorption of aerosols at coastal sites in Qingdao. The average values and standard deviations of the absorption coefficient (OAC) at λ = 1064 nm during the measurement period were 18.52 ± 13.31 Mm−1. Combined with the backward trajectory model, the aerosol absorption coefficient and gas pollution concentration of six possible air mass trajectories were obtained and calculated. The maximum absorption coefficient of local air masses was approximately 20.4 Mm−1 and anthropogenic pollution originated from mainly local sources in the Jiaozhou area. In our measurements at this site, the results also showed that there was a positive correlation between relative humidity (RH) and aerosol absorption. Without considering other factors, the size of aerosol particles grew with the increasing of RH, which changed the nonlinear relationship between the size and the absorption cross section of aerosol particles subsequently. In addition, the correlations between gas pollutants and OAC were calculated. The atmospheric environment is complex in sea–land intersection areas, especially in coastal cities. Analysis of various aerosol sources, meteorological conditions, and gas precursors enhances the study of aerosol optical absorption.

scholarly journals Production of particulate brown carbon during atmospheric aging of residential wood-burning emissions

2018 ◽  
Vol 18 (24) ◽  
pp. 17843-17861 ◽  
Author(s):  
Nivedita K. Kumar ◽  
Joel C. Corbin ◽  
Emily A. Bruns ◽  
Dario Massabó ◽  
Jay G. Slowik ◽  
...  
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Wavelength Dependence ◽  
Organic Aerosol ◽  
Geometric Standard Deviation ◽  
Wood Combustion ◽  
Brown Carbon ◽  
Atmospheric Aging ◽  
Aerosol Absorption ◽  
Uv Visible

Abstract. We investigate the optical properties of light-absorbing organic carbon (brown carbon) from domestic wood combustion as a function of simulated atmospheric aging. At shorter wavelengths (370–470 nm), light absorption by brown carbon from primary organic aerosol (POA) and secondary organic aerosol (SOA) formed during aging was around 10 % and 20 %, respectively, of the total aerosol absorption (brown carbon plus black carbon). The mass absorption cross section (MAC) determined for black carbon (BC, 13.7 m2 g−1 at 370 nm, with geometric standard deviation GSD =1.1) was consistent with that recommended by Bond et al. (2006). The corresponding MAC of POA (5.5 m2 g−1; GSD =1.2) was higher than that of SOA (2.4 m2 g−1; GSD =1.3) at 370 nm. However, SOA presents a substantial mass fraction, with a measured average SOA ∕ POA mass ratio after aging of ∼5 and therefore contributes significantly to the overall light absorption, highlighting the importance of wood-combustion SOA as a source of atmospheric brown carbon. The wavelength dependence of POA and SOA light absorption between 370 and 660 nm is well described with absorption Ångström exponents of 4.6 and 5.6, respectively. UV-visible absorbance measurements of water and methanol-extracted OA were also performed, showing that the majority of the light-absorbing OA is water insoluble even after aging.

Diffuse Reflectance and Transmission Measurements on LiF:Mg,Cu,P Powders and Single Crystals

1993 ◽  
Vol 47 (1-4) ◽  
pp. 123-127 ◽  
Author(s):  
J. McKeever ◽  
D. Macintyre ◽  
S.R. Taylor ◽  
S.W.S. McKeever ◽  
A. Horowitz ◽  
...  
Keyword(s):  
Single Crystals ◽  
Diffuse Reflectance ◽  
Transmission Measurements

scholarly journals Characterization and intercomparison of aerosol absorption photometers: result of two intercomparison workshops

2011 ◽  
Vol 4 (2) ◽  
pp. 245-268 ◽  
Author(s):  
T. Müller ◽  
J. S. Henzing ◽  
G. de Leeuw ◽  
A. Wiedensohler ◽  
A. Alastuey ◽  
...  
Keyword(s):  
Aerosol Particles ◽  
Spot Size ◽  
High Variability ◽  
Flow Rates ◽  
Aerosol Absorption ◽  
Large Sets ◽  
Different Types ◽  
Total Particle ◽  
Noise Measurements ◽  
Real Time Application

Abstract. Absorption photometers for real time application have been available since the 1980s, but the use of filter-based instruments to derive information on aerosol properties (absorption coefficient and black carbon, BC) is still a matter of debate. Several workshops have been conducted to investigate the performance of individual instruments over the intervening years. Two workshops with large sets of aerosol absorption photometers were conducted in 2005 and 2007. The data from these instruments were corrected using existing methods before further analysis. The inter-comparison shows a large variation between the responses to absorbing aerosol particles for different types of instruments. The unit to unit variability between instruments can be up to 30% for Particle Soot Absorption Photometers (PSAPs) and Aethalometers. Multi Angle Absorption Photometers (MAAPs) showed a variability of less than 5%. Reasons for the high variability were identified to be variations in sample flow and spot size. It was observed that different flow rates influence system performance with respect to response to absorption and instrumental noise. Measurements with non absorbing particles showed that the current corrections of a cross sensitivity to particle scattering are not sufficient. Remaining cross sensitivities were found to be a function of the total particle load on the filter. The large variation between the response to absorbing aerosol particles for different types of instruments indicates that current correction functions for absorption photometers are not adequate.

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