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Impacts of Volatilisation on Light Scattering and Filter-based Absorption Measurements: a Case Study : Volume 3, Issue 5 (06/09/2010)

By Backman, J.

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Book Id: WPLBN0003977631
Format Type: PDF Article :
File Size: Pages 12
Reproduction Date: 2015

Title: Impacts of Volatilisation on Light Scattering and Filter-based Absorption Measurements: a Case Study : Volume 3, Issue 5 (06/09/2010)  
Author: Backman, J.
Volume: Vol. 3, Issue 5
Language: English
Subject: Science, Atmospheric, Measurement
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2010
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Backman, J., Virkkula, A., Frey, A., Aurela, M., Petäjä, T., & Hillamo, R. (2010). Impacts of Volatilisation on Light Scattering and Filter-based Absorption Measurements: a Case Study : Volume 3, Issue 5 (06/09/2010). Retrieved from http://www.worldebookfair.com/


Description
Description: Department of Physics, University of Helsinki, P.O. Box 64, 00014, Finland. Aerosol light absorption measurements most commonly rely on filter-based techniques. These methods are influenced by light scattering constituents in the aerosol phase deposited on the filters. The coating of soot by non-absorbing constituents changes the mixing state of soot as the aerosol ages and increase light absorption by the aerosol. Most light scattering constituents in a sub-micron aerosol are volatile by their nature due to their chemical composition and can be volatilized by heating the sample air. The initial mixing state is lost but the remaining light absorption by the aerosol should be by non-coated soot alone.

This was studied during a short field campaign with two groups of equipment measuring in parallel for six days in April 2009 at the SMEAR III station in Helsinki. When heated, the light scattering constituents were evaporated thus reducing the single-scattering albedo (Ω0) of the aerosol by as much as 0.4. An oven was set to scan different temperatures which revealed the volatility of the urban aerosol at different temperatures as well as the single-scattering albedo's dependence on the non-volatile volume fraction remaining (NVFR). The NVFR was 0.72 ± 0.13, 0.42 ± 0.06 and 0.22 ± 0.05 at 50, 150 and 280 °C respectively. Ω0 behaved analogically, it was 0.71 ± 0.05, 0.62 ± 0.06 and 0.42 ± 0.07 at the respective temperatures. We found that absorption coefficients measured at different temperatures showed a temperature dependency possibly indicating initially different mixing states of the non-volatile constituents.

By heating the aerosol the mode of the size distribution gets shifted to smaller sizes which in turn changes the filter-based instrument's response due increased penetration depth into the filter by the smaller residual particles. This was compensated for by using size distribution data.


Summary
Impacts of volatilisation on light scattering and filter-based absorption measurements: a case study

Excerpt
Aalto, P., H{ä}meri, K., Becker, E., Weber, R., Salm, J., M{ä}kel{ä}, J., Hoell, C., O'Dowd, C., Karlsson, H., Hansson, H.-C., V{ä}kev{ä}, M., Koponen, I., Buzorius, G., and Kulmala, M.: Physical characterization of aerosol particles during nucleation events., Tellus, 53B, 344–358, 2001.; An, W. J., Pathak, R., Lee, B.-H., and Pandis, S.: Aerosol volatility measurement using an improved thermodenuder: Application to secondary organic aerosol, J. Aerosol Sci., 38, 305–314, 2007.; Anderson, T., Covert, D., Marshall, S., Laucks, M., Charlson, R., Waggoner, A., Ogren, J., Caldow, R., Holm, R., Quant, F., Sem, G., Wiedensohler, A., Ahlquist, N., and Bates, T.: Performance characteristics of a high-sensitivity, three-wavelength, total scatter/backscatter nephelometer, J. Atmos. Ocean. Tech., 13, 967–985, 1996.; Arnott, W., Hamasha, K., Moosm{ü}ller, H., Sheridan, P., and Ogren, J.: Towards aerosol light-absorption measurements with a 7-wavelength aethalometer: evaluating with a photoacoustic instrument and 3-wavelength nephelometer, Aerosol Sci. Tech., 39, 17–29, 2005.; Backman, J.: Aerosolpartiklars flyktighet och deras optiska egenskaper, Master's thesis, University of Helsinki, Helsinki, 2009.; Barber, P. and Hill, S.: Light Scattering by Particles: Computational Methods, World Scientific Pub Co Inc, 1990.; Birch, M. and Cary, R.: Elemental Carbon-Based Method for Monitoring Occupational Exposures to Particulate Diesel Exhaust, Aerosol Sci. Tech., 25, 221–241, 1996.; Bond, T. and Bergstrom, R.: Light Absorption by Carbonaceous Particles: An Investigative Review, Aerosol Sci. Tech., 40, 27–67, 2006.; Bond, T., Anderson, T., and Campbell, D.: Calibration and Intercomparison of Filter-Based Measurements of Visible Light Absorption by Aerosols, Aerosol Sci. Tech., 30, 582–600, 1999.; Cabada, J., Khlystov, A., Wittig, A., Pilinis, C., and Pandis, S.: Light Scattering by fine particles during the Pittsburg Air Quality Study: Measurements and modeling, J. Geophys. Res., 109, D16S03, doi:10.1029/2003JD004155, 2004.; Cavalli, F., Viana, M., Yttri, K. E., Genberg, J., and Putaud, J.-P.: Toward a standardised thermal-optical protocol for measuring atmospheric organic and elemental carbon: the EUSAAR protocol, Atmos. Meas. Tech., 3, 79–89, 2010.; Engler, C., Rose, D., Wehner, B., Wiedensohler, A., Brüggemann, E., Gnauk, T., Spindler, G., Tuch, T., and Birmili, W.: Size distributions of non-volatile particle residuals (D$_{p}<$800 nm) at a rural site in Germany and relation to air mass origin, Atmos. Chem. Phys., 7, 5785–5802, doi:10.5194/acp-7-5785-2007, 2007.; Fuller, K., Malm, W., and Kreidenweis, S.: Effects of mixing on extinction by carbonaceous particles, J. Geophys. Res., 104(D13), 941–954, doi:10.1029/1998JD100069, 1999.; Hansen, A., Rosen, H., and Novakov, T.: The Aethalometer-An instrument for the real-time measurement of optical absorption by aerosol particles, Sci. Total Environ., 36, 191–196, 1984.; Heintzenberg, J., Wiedensohler, A., Tuch, T., Covert, D., Sheridan, P., Ogren, J., Gras, J., Nessler, R., Kleefeld, C., Kalivitis, N., Aaltonen, V., Wilhelm, R.-T., and Havlicek, M.: Intercomparisons and Aerosol Calibrations of 12 Commercial Integrating Nephelometers of Three Manufacturers, J. Atmos. Ocean. Tech., 23, 902–914, 2006.; Hoppel, W.: Determination of the aerosol size distribution from the mobility distribution of the charged fraction of aerosols, J. Aerosol Sci., 9, 41–54, doi:10.1016/0021-8502(78)90062-9, 1978.; Jacobson, M.: Strong radiative heating due to the mixing state of black carbon in atmospheric aerosols, Nature, 409, 695–697, 2001.; J{ä}rvi, L., Hannuniemi, H., Hussein, T., Junninen, H., Aalto, P., Hillamo, R., M{ä}kel{ä}, T., Keronen, P., Siivola, E., Vesala, T., and Kulmala, M.: The urban measurement st

 

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