ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-8-1823-2008 Extinction efficiencies of coated absorbing aerosols measured by cavity ring down aerosol spectrometry Abo Riziq A. 1 Trainic M. 1 Erlick C. 2 Segre E. 3 Rudich Y. 1 Department of Environmental Sciences, Weizmann Institute, Rehovot, 76100, Israel Department of Atmospheric Sciences, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel Physics Services, Weizmann Institute, Rehovot, 76100, Israel 26 03 2008 8 6 1823 1833 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/8/1823/2008/acp-8-1823-2008.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/8/1823/2008/acp-8-1823-2008.pdf

In this study, we measure the extinction efficiency at 532 nm of absorbing aerosol particles coated with a non-absorbing solid and liquid organic shell with coating thickness varying between 5 and 100 nm using cavity ring down aerosol spectrometry. For this purpose, we use nigrosin, an organic black dye, as a model absorbing core and two non-absorbing organic substances as shells, glutaric acid (GA) and Di-Ethyl-Hexyl-Sebacate (DEHS). The measured behavior of the coated particles is consistent with Mie calculations of core-shell particles. Errors between measured and calculated values for nigrosin coated with GA and DEHS are between 0.5% and 10.5% and between 0.5% and 9%, respectively. However, it is evident that the calculations are in better agreement with the measured results for thinner coatings. Possible reasons for these discrepancies are discussed.

 References Alexanderkatz, R.: Scattering pattern of a quasitransparent core-shell particle, Phys. Rev. A., 42, 6816–6822, 1990. Bohren, C. F. and Huffman, D. R.: Absorption and scattering of light by small particles, 530 pp., Wiley, 1983. Bond, T. C. and Bergstrom, R. W.: Light absorption by carbonaceous particles: An investigative review, Aerosol Sci. Tech., 40, 27–67, 2006. Borghese, F., Denti, P., Saija, R., Iati, M. A., and Sindoni, O. I.: Optical resonances of spheres containing an eccentric spherical inclusion, J. Opt., 29, 28–34, 1998. Chung, S. H. and Seinfeld, J. H.: Global distribution and climate forcing of carbonaceous aerosols, J. Geophys. Res.-Atmos., 107, 4407, doi:4410.1029/2001JD001397, 2002. Ch\'ylek, P. and Hallett, J.: Enhanced absorption of solar-radiation by cloud droplets containing soot particles in their surface, Q. J. Roy. Meteor. Soc., 118, 167–172, 1992. Ch\'ylek, P., Lesins, G. B., Videen, G., Wong, J. G. D., Pinnick, R. G., Ngo, D., and Klett, J. D.: Black carbon and absorption of solar radiation by clouds, J. Geophys. Res.-Atmos., 101, 23 365–23 371, 1996. Dinar, E., Riziq, A. A., Spindler, C., Erlick, C., Kiss, G., and Rudich, Y.: The complex refractive index of atmospheric and model humic-like substances (HULIS) retrieved by a cavity ring down aerosol spectrometer (CRD-AS), Faraday Discuss., 137, 279–295, 2008. Falkovich, A. H., Schkolnik, G., Ganor, E., and Rudich, Y.: Adsorption of organic compounds pertinent to urban environments onto mineral dust particles, J. Geophys. Res.-Atmos., 109, D01201, doi:01210.01029/02003JD003919, 2004. Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D. W., Haywood, J., Lean, J., Lowe, D. C., Myhre, G., Nganga, J., Prinn, R., Raga, G., Schulz, M., and Van Dorland, R.: Changes in Atmospheric Constituents and in Radiative Forcing, in: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, 160–170, 2007. Friedman, S. P.: A saturation degree-dependent composite spheres model for describing the effective dielectric constant of unsaturated porous media, Water Resour. Res., 34, 2949–2961, 1998. Fuller, K. A.: Scattering and absorption cross-sections of compounded spheres, 3, Spheres containing arbitrarily aocated spherical inhomogeneities, J. Opt. Sci. Am. A., 12, 893–904, 1995. Fuller, K. A., Malm, W. C., and Kreidenweis, S. M.: Effects of mixing on extinction by carbonaceous particles, J. Geophys. Res.-Atmos., 104, 15 941–15 954, 1999. Garvey, D. M. and Pinnick, R. G.: Response Characteristics Of The Particle Measuring Systems Active Scattering Aerosol Spectrometer Probe (Asasp-X), Aerosol Sci. Tech., 2, 477–488, 1983. Gelencser, A.: Carbonaceous Aerosol, Springer, 352 pp., 2004. Goodman, A. L., Underwood, G. M., and Grassian, V. H.: A laboratory study of the heterogeneous reaction of nitric acid on calcium carbonate particles, J. Geophys. Res.-Atmos., 105, 29 053–29 064, 2000. Griaznov, V., Veselovskii, I., Di Girolamo, P., Demoz, B., and Whiteman, D. N.: Numerical simulation of light backscattering by spheres with off-center inclusion. Application to the lidar case, Appl. Optics, 43, 5512–5522, 2004. Guazzotti, S. A., Whiteaker, J. R., Suess, D., Coffee, K. R., and Prather, K. A.: Real-time measurements of the chemical composition of size-resolved particles during a Santa Ana wind episode, California USA, Atmos. Environ., 35, 3229–3240, 2001. Ioannidou, M. P., Bakatsoula, I. I., and Chrissoulidis, D. P.: Light scattering and absorption by soot in the presence of sulfate aerosols, Appl. Optics, 39, 4205–4213, 2000. Jacobson, M. Z.: A physically-based treatment of elemental carbon optics: Implications for global direct forcing of aerosols, Geophys. Res. Lett., 27, 217–220, 2000. Kaufman, Y. J. and Fraser, R. S.: The effect of smoke particles on clouds and climate forcing, Science, 277, 1636–1639, 1997. Kaufman, Y. J., Tanre, D., and Boucher, O.: A satellite view of aerosols in the climate system, Nature, 419, 215–223, 2002. Kirchstetter, T. W., Novakov, T., and Hobbs, P. V.: Evidence that the spectral dependence of light absorption by aerosols is affected by organic carbon, J. Geophys. Res.-Atmos., 109, D21208, doi:21210.21029/22004JD004999, 2004. Koren, I., Kaufman, Y. J., Rosenfeld, D., Remer, L. A., and Rudich, Y.: Aerosol invigoration and restructuring of Atlantic convective clouds, Geophys. Res. Lett., 32, L14828, doi:14810.11029/12005GL023187, 2005. Kousaka, Y., Endo, Y., Alonso, M., Ichitsubo, H., and Fukui, A.: Nanometer Coating On Aerosol-Particles, Adv. Powder Tech., 6, 11–24, 1995. Krueger, B. J., Grassian, V. H., Cowin, J. P., and Laskin, A.: Heterogeneous chemistry of individual mineral dust particles from different dust source regions: the importance of particle mineralogy, Atmos. Environ., 38, 6253–6261, 2004. Krueger, B. J., Grassian, V. H., Laskin, A., and Cowin, J. P.: The transformation of solid atmospheric particles into liquid droplets through heterogeneous chemistry: Laboratory insights into the processing of calcium containing mineral dust aerosol in the troposphere, Geophys. Res. Lett., 30, 1148, doi:1110.1029/2002GL016563, 2003. Lack, D. A., Lovejoy, E. R., Baynard, T., Pettersson, A., and Ravishankara, A. R.: Aerosol absorption measurement using photoacoustic spectroscopy: Sensitivity, calibration, and uncertainty developments, Aerosol Sci. Tech., 40, 697–708, 2006. LaFortune, K. N. and Hall, D. G.: Dipole-waveguide coupling in nonlinear systems, J. Opt. Soc. Am. B, 19, 860–869, 2002. Laskin, A., Iedema, M. J., Ichkovich, A., Graber, E. R., Taraniuk, I., and Rudich, Y.: Direct observation of completely processed calcium carbonate dust particles, Faraday Discuss., 130, 453–468, 2005. Lazarev, S., Mirjanic, D., Mitranic, L., and Pantic, M.: Dielectric properties of ultrathin films of molecular crystals, J. Phys. Chem. Solids, 64, 715–722, 2003. Lesins, G., Ch\'ylek, P., and Lohmann, U.: A study of internal and external mixing scenarios and its effect on aerosol optical properties and direct radiative forcing, J. Geophys. Res.-Atmos., 107, 4094, doi:4010.1029/2001JD000973, 2002. Maria, S. F., Russell, L. M., Gilles, M. K., and Myneni, S. C. B.: Organic aerosol growth mechanisms and their climate-forcing implications, Science, 306, 1921–1924, 2004. Mishchenko, M. I.: Light-scattering by randomly oriented axially symmetrical particles, J. Opt. Sci. Am. A., 8, 871–882, 1991. Ngo, D. and Pinnick, R. G.: Suppression of scattering resonances in inhomogeneous microdroplets, J. Opt. Sci. Am. A., 11, 1352–1359, 1994. Ngo, D., Videen, G., and Ch\'ylek, P.: A FORTRAN code for the scattering of EM waves by a sphere with a nonconcentric spherical inclusion, Comp. Phys. Comm., 99, 94–112, 1996. Oates, T. W. H., McKenzie, D. R., and Bilek, M. M. M.: Percolation threshold in ultrathin titanium films determined by in situ spectroscopic ellipsometry, Phys. Rev. B, 70, 1–6, 2004. Peterson, M. S. M., Bouwman, J., Chen, A. Q., and Deutsch, M.: Inorganic metallodielectric materials fabricated using two single-step methods based on the Tollen's process, J. Colloid Interf. Sci., 306, 41–49, 2007. Pettersson, A., Lovejoy, E. R., Brock, C. A., Brown, S. S., and Ravishankara, A. R.: Measurement of aerosol optical extinction at 532 nm with pulsed cavity ring down spectroscopy, J. Aerosol Sci., 35, 995–1011, 2004. Prabhu, D. R., Davies, M., and Videen, G.: Light scattering calculations from oleic-acid droplets with water inclusions, Optics Express, $8$, 308-313, 2001. Quirantes, A.: A T-matrix method and computer code for randomly oriented, axially symmetric coated scatterers, J. Quant. Spectros. Ra., 92, 373–381, 2005. Quirantes, A. and Delgado, A. V.: Scattering cross sections of randomly oriented coated spheroids, J. Quant. Spectros. Ra., 70, 261–272, 2001. Ramanathan, V., Chung, C., Kim, D., Bettge, T., Buja, L., Kiehl, J. T., Washington, W. M., Fu, Q., Sikka, D. R., and Wild, M.: Atmospheric brown clouds: Impacts on South Asian climate and hydrological cycle, Proc. Natl. Acad. Sci. USA, 102, 5326–5333, 2005. Ramanathan, V., Ramana, M. V., Roberts, G., Kim, D., Corrigan, C., Chung, C., and Winker, D.: Warming trends in Asia amplified by brown cloud solar absorption, Nature, 448, 575–U575, 2007. Res, J. G., Schwarz, J. P., Gao, R. S., Fahey, D. W., Thomson, D. S., Watts, L. A., Wilson, J. C., Reeves, J. M., Darbeheshti, M., Baumgardner, D. G., Kok, G. L., Chung, S. H., Schulz, M., Hendricks, J., Lauer, A., Karcher, B., Slowik, J. G., Rosenlof, K. H., Thompson, T. L., Langford, A. O., Loewenstein, M., and Aikin, K. C.: Single-particle measurements of midlatitude black carbon and light-scattering aerosols from the boundary layer to the lower stratosphere, J. Geophys. Res.-Atmos., 111, D16207, doi:10.1029/2006JD007076, 2006. Riziq, A. A., Erlick, C., Dinar, E., and Rudich, Y.: Optical properties of absorbing and non-absorbing aerosols retrieved by cavity ring down (CRD) spectroscopy, Atmos. Chem. Phys., 7, 1523–1536, 2007. Rohde, C. A., Hasegawa, K., and Deutsch, M.: Coherent light scattering from semicontinuous silver nanoshells near the percolation threshold, Phys. Rev. Lett., 96, 045503, 045503-045501 to 045504, 2006. Roselli, D.: Development and test of a system for simultaneous measurement of hygroscopic properties and chemical composition of multi-component aerosols, Univerista degli Studi "Carlo Bo" of Urbino, Urbino, Italy, 2006. Russell, L. M., Maria, S. F., and Myneni, S. C. B.: Mapping organic coatings on atmospheric particles, Geophys. Res. Lett., 29, 1779, doi:10.1029/2002GL014874, 2002. Shi, W. L., Sahoo, Y., Swihart, M. T., and Prasad, P. N.: Gold nanoshells on polystyrene cores for control of surface plasmon resonance, Langmuir, 21, 1610–1617, 2005. Shi, W. L., Zeng, H., Sahoo, Y., Ohulchanskyy, T. Y., Ding, Y., Wang, Z. L., Swihart, M., and Prasad, P. N.: A general approach to binary and ternary hybrid nanocrystals, Nano Lett., 6, 875–881, 2006. Spindler, C., Abo Riziq, A., and Rudich, Y.: Retrieval of aerosol complex refractive index by combining cavity ring down aerosol spectrometer measurement with full size distribution information, Aerosol Sci. Tech., 41, 1011–1017, 2007. Sun, H. L., Biedermann, L., and Bond, T. C.: Color of brown carbon: A model for ultraviolet and visible light absorption by organic carbon aerosol, Geophys. Res. Lett., 34, L17813, doi:17810.11029/12007GL029797, 2007. Toon, O. B. and Ackerman, T. P.: Algorithms for the calculation of scattering sy stratified spheres, Appl. Optics, 20, 3657–3660, 1981. Tu, H. H. and Ray, A. K.: Investigation of concentrically and eccentrically layered droplets by light scattering, Appl. Optics, 45, 7652–7656, 2006. Videen, G., Ngo, D., and Ch\'ylek P.: Effective-medium predictions of absorption gy graphitic carbon in water droplets, Optics Lett., 19, 1675–1677, 1994. Wesselinowa, J. M.: Dielectric function of antiferroelectric thin films, Phys. Status Solidi B, 242, 1528–1536, 2005. Wesselinowa, J. M. and Trimper, S.: Thickness dependence of the dielectric function of ferroelectric thin films, Phys. Status Solidi B, 241, 1141–1148, 2004. Zhang, Q., Canagaratna, M. R., Jayne, J. T., Worsnop, D. R., and Jimenez, J. L.: Time- and size-resolved chemical composition of submicron particles in Pittsburgh: Implications for aerosol sources and processes, J. Geophys. Res.-Atmos., 110, D07S09, doi:10.1029/2004JD004649, 2005.