Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 8 2 2008 10.5194/acpd-8-6845-2008 http://www.atmos-chem-phys-discuss.net/8/6845/2008/ http://www.atmos-chem-phys-discuss.net/8/6845/2008/acpd-8-6845-2008.html http://www.atmos-chem-phys-discuss.net/8/6845/2008/acpd-8-6845-2008.pdf 6845 6901 2008-04-09 Aerosol optical properties in a rural environment near the mega-city Guangzhou, China: implications for regional air pollution and radiative forcing R. M. Garland garland@mpch-Mainz.mpg.de H. Yang O. Schmid D. Rose A. Nowak P. Achtert A. Wiedensohler N. Takegawa K. Kita Y. Miyazaki Y. Kondo M. Hu M. Shao L. Zeng Y. Zhang M. O. Andreae U. Pöschl Biogeochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany Helmholtz Center Munich, German Research Center for Environmental Health, Institute for Inhalation Biology, Neuherberg/Munich, Germany College of Environmental Sciences, Peking University, Beijing, China Leibniz Institute for Tropospheric Research, Leipzig, Germany RCAST, University of Tokyo, Tokyo, Japan The scattering and absorption of solar radiation by atmospheric aerosols is a key element of the Earth's radiative energy balance and climate. The optical properties of aerosol particles are, however, highly variable and not well characterized, especially near newly emerging mega-cities. In this study, aerosol optical properties were measured at a regional background site approximately 60 km northwest of the mega-city Guangzhou in southeast China. The measurements were part of the "Program of Regional Integrated Experiments of Air Quality over the Pearl River Delta" intensive campaign (PRIDE-PRD2006), covering the period of 1–30 July 2006. Scattering and absorption coefficients of dry aerosol particles with diameters up to 10 μm (PM10) were determined with a three-wavelength integrating nephelometer and with a photoacoustic spectrometer, respectively. Averaged over the measurement campaign (arithmetic mean ±standard deviation), the total scattering coefficients were 200±133 Mm−1 (450 nm), 151±103 Mm−1 (550 nm) and 104±72 Mm−1 (700 nm) and the absorption coefficient was 34.3±26.5 Mm−1 (532 nm). The average Ångström exponent was 1.46±0.21 (450 nm/700 nm) and the average single scattering albedo was 0.82±0.07 (532 nm) with minimum values as low as 0.5. The low single scattering albedo values indicate a high abundance of, as well as strong sources of light absorbing carbon (LAC). The ratio of LAC to CO concentration was highly variable throughout the campaign, indicating a complex mix of different combustion sources. The scattering and absorption coefficients, as well as the Ångström exponent and single scattering albedo, exhibited pronounced diurnal cycles, which can be attributed to boundary layer mixing effects and enhanced nighttime emissions of LAC (diesel soot from regulated truck traffic). The daytime average single scattering albedo of 0.87 appears to be more suitable for climate modeling purposes than the 24-h average of 0.82, as the latter value is strongly influenced by fresh emissions into a shallow nocturnal boundary layer. In spite of high photochemical activity during daytime, we found no evidence for strong local production of secondary aerosol mass. The relatively low average mass scattering efficiency with respect to PM10 (2.84±0.037 m2 g−1, λ=550 nm) indicates a high proportion of mass in the coarse particle fraction (diameter >1 μm). During high pollution episodes, however, the Ångström exponent exhibited a dependence on wavelength, which indicates an enhancement of the fine particle fraction during these periods. A negative correlation between single scattering albedo and backscatter fraction was observed and found to affect the impact that these parameters have on aerosol radiative forcing efficiency. Adam, M., Pahlow, M., Kovalev, V. A., Ondov, J. M., Parlange, M. B., and Nair, N.: Aerosol optical characterization by nephelometer and lidar: The Baltimore Supersite experiment during the Canadian forest fire smoke intrusion, J. Geophys. Res.-Atmos. 109, D16S02, doi:10.1029/2003JD004047, 2004. Anderson, T. L., Covert, D. S., Marshall, S. F., Laucks, M. L., Charlson, R. J., Waggoner, A. P., Ogren, J. A., Caldow, R., Holm, R. L., Quant, F. R., Sem, G. J., Wiedensohler, A., Ahlquist, N. A., and Bates, T. S.: Performance characteristics of a high-sensitivity, three-wavelength, total scatter/backscatter nephelometer, J. Atmos. Ocean. Technol., 13(5), 967–986, 1996. Anderson, T. L., Covert, D. S., Wheeler, J., Harris, J., Perry, K., Trost, B., Jaffe, D., and Ogren, J.: Aerosol backscatter fraction and single scattering albedo: Measured values and uncertainties at a coastal station in the Pacific Northwest, J. Geophys. Res.-Atmos., 104(D21), 26 793–26 807, 1999. Anderson, T. L., S. J. Masonis, Covert, D. S., Ahlquist, N. C., Howell, S. G., Clarke, A. D., and McNaughton, C. S.: Variability of aerosol optical properties derived from in situ aircraft measurements during ACE-Asia, J. Geophys. Res.-Atmos., 108(D23), 8647, doi:10.1029/2002JD003247, 2003. Anderson, T. L. and J. A. Ogren: Determining aerosol radiative properties using the TSI 3563 integrating nephelometer, Aerosol Sci. Tech., 29(1), 57–69, 1998. Andreae, M. O. and A. Gelencser: Black carbon or brown carbon? The nature of light-absorbing carbonaceous aerosols, Atmos. Chem. Phys., 6, 3131–3148, 2006. Andreae, M. O., Schmid, O., Yang, H., Yu, J.-Z., and Zhang, Y.-H.: Optical properties and chemical composition of the atmospheric aerosol in urban Guangzhou, China, Atmos. Environ., doi:10.1016/j.atmosenv.2008.01.030, 2008. Andreae, T. W., Andreae, M. O., Ichoku, C., Maenhaut, W., Cafmeyer, J., Karnieli, A., and Orlovsky, L.: Light scattering by dust and anthropogenic aerosol at a remote site in the Negev desert, Israel, J. Geophys. Res.-Atmos., 107(D2), 4008, doi:10.1029/2001JD900252, 2002. Ångström, A.: On the atmospheric transmission of sun radiation and on dust in the air, Geografiska Annaler, 11, 156–166, 1929. Arnott, W. P., Moosmuller, H., Rogers, C. F., Jin, T. F., and Bruch, R.: Photoacoustic spectrometer for measuring light absorption by aerosol: instrument description, Atmos. Environ., 33(17), 2845–2852, 1999. Arnott, W. P., Moosmuller, H., and Walker, J. W.: Nitrogen dioxide and kerosene-flame soot calibration of photoacoustic instruments for measurement of light absorption by aerosols, Rev. Sci. Instrum., 71(12), 4545–4552, 2000. Ayers, G. P.: Comment on regression analysis of air quality data, Atmos. Environ., 35(13), 2423–2425, 2001. Baumgardner D., Raga, G., Peralta, O., Rosas, I., Castro, T., Kuhlbusch, T., John, A., and Petzold, A.: Diagnosing black carbon trends in large urban areas using carbon monoxide measurements, J. Geophys. Res., 107(D21), 8342, doi:10.1029/2001JD000626, 2002. Baumgardner, D.: On the diurnal variability of particle properties related to light absorbing carbon in Mexico City, Atmos. Chem. Phys., 7, 2517–2526, 2007. Bergin, M. H., Cass, G. R., Xu, J., Fang, C., Zeng, L. M., Yu, T., Salmon, L. G., Kiang, C. S., Tang, X. Y., Zhang, Y. H., and Chameides, W. L.: Aerosol radiative, physical, and chemical properties in Beijing during June 1999, J. Geophys. Res.-Atmos., 106(D16), 17 969–17 980, 2001. Bond, T. C.: Light absorption by carbonaceous particles: An investigative review, Aerosol Sci. Tech., 40(1), 27–67, 2006. Bradsher, K.: Trucks power China's economy, at a suffocating cost, The New York Times, NY, 2007. Cao, J. J., Lee, S. C., Ho, K. F., Zhang, X. Y., Zou, S. C., Fung, K., Chow, J. C., and Watson, J. G: Characteristics of carbonaceous aerosol in Pearl River Delta Region, China during 2001 winter period, Atmos. Environ., 37(11), 1451–1460, 2003. Cao, J. J., Lee, S. C., Ho, K. F., Zou, S. C., Fung, K., Li, Y., Watson, J. G., and Chow, J. C.: Spatial and seasonal variations of atmospheric organic carbon and elemental carbon in Pearl River Delta Region, China, Atmos. Environ., 38(27), 4447–4456, 2004. Carrico, C. M., Bergin, M. H. , Xu, J., Baumann, K., and Maring, H.: Urban aerosol radiative properties: Measurements during the 1999 Atlanta Supersite Experiment, J. Geophys. Res.-Atmos., 108(D7), 8422, doi:10.1029/2001JD001222, 2003. Chen, L. W. A., Doddridge, B. G., Dickerson, R., Chow, J., Mueller, P., Quinn, J., and Butler, W.: Seasonal variations in elemental carbon aerosol, carbon monoxide and sulfur dioxide: Implications for sources, Geophys. Research Lett., 28(9), 1711–1714, 2001. Cheng, Y., Lee, S. C., Ho, K. F., Wang, Y. Q., Cao, J. J. , Chow, J. C., and Watson, J. G.: Black carbon measurement in a coastal area of south China, J. Geophys. Res.-Atmos., 111, D12310, doi:10.1029/2005JD006663, 2006. Cheng, Y. F., Eichler, H., Wiedensohler, A., Heintzenberg, J., Zhang, Y. H., Hu, M., Herrmann, H., Zeng, L. M., Liu, S., Gnauk, T., Bruggemann, E., and He, L. Y.: Mixing state of elemental carbon and non-light-absorbing aerosol components derived from in situ particle optical properties at Xinken in Pearl River Delta of China, J. Geophys. Res.-Atmos. 111(D20), D20204, doi:10.1029/2005JD006929, 2006. Draxler, R. R. and Rolph, G. D.: HYSPLIT (HYbrid Single-Partilce Lagrangian Integrated Trajectory), available at: http://www.arl.noaa.gov/ready/hysplit4.html, 2003. Eck, T. F., Holben, B. N., Reid, J., Dubovik, O., Smirnov, A., O'Neill, N., Slutsker, I., and Kinne, S.: Wavelength dependence of the optical depth of biomass burning, urban, and desert dust aerosols, J. Geophys. Res.-Atmos., 104(D24), 31 333–31 349, 1999. Eck, T. F., B. N. Holben, Ward, D., Dubovik, O., Reid, J., Smirnov, A., Mukelabai, M., Hsu, N., O'Neill, N., and Slutsker, I.: Characterization of the optical properties of biomass burning aerosols in Zambia during the 1997 ZIBBEE field campaign, J. Geophys. Res.-Atmos., 106(D4), 3425–3448, 2001. Fialho, P., Hansen, A. D. A., and Honrath, R. E.: Absorption coefficients by aerosols in remote areas: a new approach to decouple dust and black carbon absorption coefficients using seven-wavelength Aethalometer data, J. Aerosol Sci., 36(2), 267–282, 2005. Finlayson-Pitts, B. and Pitts Jr., J.: Chemistry of the Upper and Lower Atmosphere, New York, Academic Press, 1999. Fujitani, Y., Murao, N., Ohta, S. , Endoh, T., and Yamagata, S.: Optical and chemical properties of marine aerosols over the central equatorial Pacific Ocean during the 2003 R/V Mirai cruise, J. Geophys. Res., 112, (D11213), doi:10.1029/2006JD008354, 2007. % %Gnauk, T., Mueller, K., van Pinxteren, D., He, L. Y., Niu, Y., Hu, M., and Herrmann, H.: Size-segregated particulate chemical %composition in Xinken, Pearl River Delta, China: OC/EC and organic %compounds, Atmos. Environ., submitted, 2008. Gobbi, G. P., Kaufman, Y. J., Koren, I., and Eck, T. F.: Classification of aerosol properties derived from AERONET direct sun data, Atmos. Chem. Phys., 7, 453–458, 2007. Hammer, Ø., Harper, D. A. T., and Ryan, P. D.: PAST: Paleontological Statistics Software Package for Education and Data Analysis, Palaeontol. Electron., 4(1), 1–9, 2001. Haywood, J. M. and Shine, K. P.: The Effect of Anthropogenic Sulfate and Soot Aerosol on the Clear-Sky Planetary Radiation Budget, Geophys. Research Lett., 22(5), 603–606, 1995. IPCC: Climate Change 2001: The Scientific Basis, 2001. Jennings, S. G., Spain, T. G., Doddridge, B., Maring, H., Kelly, B., and Hansen, A.: Concurrent measurements of black carbon aerosol and carbon monoxide at Mace Head, J. Geophys. Res.-Atmos., 101(D14), 19 447–19 454, 1996. Jiang, M., Marr, L. C., Dunlea, E. J., Herndon, S. C., Jayne, J. T., Kolb, C. E., Knighton, W. B., Rogers, T. M., Zavala, M., Molina, L. T., and Molina, M. J.: Vehicle fleet emissions of black carbon, polycyclic aromatic hydrocarbons, and other pollutants measured by a mobile laboratory in Mexico City, Atmos. Chem. Phys., 5, 3377–3387, 2005. Kaiser, D. P. and Qian, Y.: Decreasing trends in sunshine duration over China for 1954-1998: Indication of increased haze pollution?, Geophys. Research Lett., 29(21), 2042, doi:10.1029/2002GL016057, 2002. Keeling, R. F., Piper, S. C., and Heimann, M.: Global and hemispheric CO2 sinks deduced from changes in atmospheric O2 concentration, Nature, 381(6579), 218–221, 1996. Kim, K. W., He, Z. S., and Kim, Y. J.: Physicochemical characteristics and radiative properties of Asian dust particles observed at Kwangju, Korea, during the 2001 ACE-Asia intensive observation period, J. Geophys. Res.-Atmos., 109, D19S02, doi:10.1029/2003JD003693, 2004. King, M. D. and Byrne, D. M.: Method for Inferring Total Ozone Content from Spectral Variation of Total Optical Depth Obtained with a Solar Radiometer, J. Atmos. Sci., 33(11), 2242–2251, 1976. Kondo, Y., Komazaki, Y., Miyazaki, Y., Moteki, N., Takegawa, N., Kodama, D., Deguchi, S., Nogami, M., Fukuda, M., Miyakawa, T., Morino, Y., Koike, M., Sakurai, H., and Ehara, K.: Temporal variations of elemental carbon in Tokyo, J. Geophys. Res.-Atmos., 111, D12205, doi:10.1029/2005JD006257, 2006. Lawrence, M. G., Butler, T. M., Steinkamp, J., Gurjar, B. R., and Lelieveld, J.: Regional pollution potentials of megacities and other major population centers, Atmos. Chem. Phys., 7, 3969–3987, 2007. Li, C., Marufu, L. T., Dickerson, R. R., Li, Z., Wen, T., Wang, Y., Wang, P., Chen, H., and Stehr, J. W.: In situ measurements of trace gases and aerosol optical properties at a rural site in northern China during East Asian Study of Tropospheric Aerosols: An International Regional Experiment 2005, J. Geophys. Res.-Atmos., 112(D22), D22S04, doi:10.1029/2006JD007592, 2007. Li, Y., Demetriadesshah, T. H., Kanemasu, E. T., Shultis, J. K., and Kirkham, M. B.: Use of 2nd Derivatives of Canopy Reflectance for Monitoring Prairie Vegetation over Different Soil Backgrounds, Remote Sens. Environ., 44(1), 81–87, 1993. Lim, H. J.: Origins of primary and secondary organic aerosol in Atlanta: Results' of time-resolved measurements during the Atlanta supersite experiment, Environ. Sci. Technol., 36(21), 4489–4496, 2002. Liu, S. C., Hu, M., Slanina, S., He, L. Y., Niu, Y., Bruegemann, E., Gnauk, T., and Herrmann, H.: Size distribution of ionic compositions of aerosols in polluted periods at Xinken in Pearl River Delta (PRD) of China, Atmos. Environ., doi:10.1016/j.atmosenv.2007.12.035, 2008. Malm, W. C., Day, D. E., Carrico, C., Kreidenweis, S. M., Collett Jr., J. L., McMeeking, G., Lee, T., Carrillo, J., and Schichtel, B.: Intercomparison and closure calculations using measurements of aerosol species and optical properties during the Yosemite Aerosol Characterization Study, J. Geophys. Res.-Atmos., 110, D14302, doi:10.1029/2004JD005494, 2005. Nakajima, T. and A. Higurashi: A use of two-channel radiances for an aerosol characterization from space, Geophys. Res. Lett., 25(20), 3815–3818, 1998. NBS: National Bureau of Statistics of the People's Republic of China, available at: www.stats.gov.cn, 2007. Ouyang, T. P., Zhu, Z. Y., and Kuang, Y. Q.: Assessing impact of urbanization on river water quality in the Pearl River Delta Economic Zone, China, Environ. Monit. Assess., 120(1-3), 313–325, 2006. Park, S. S.: Highly time-resolved organic and elemental carbon measurements at the Baltimore Supersite in 2002, J. Geophys. Res.-Atmos. 110(D7), D07S06, doi:10.1029/2004JD004610, 2005. Poeschl, U.: Atmospheric aerosols: Composition, transformation, climate and health effects, Angew. Chem. Int. Edit., 44(46), 7520–7540, 2005. Quinn, P. K. and Bates, T. S.: Regional aerosol properties: Comparisons of boundary layer measurements from ACE 1, ACE 2, aerosols99, INDOEX, ACE asia, TARFOX, and NEAQS, J. Geophys. Res.-Atmos., 110(D14), D14202, doi:10.1029/2004JD004755, 2005. Quinn, P. K., Coffman, D. J., Kapustin, V. N., Bates, T. S., and Covert, D. S.: Aerosol optical properties in the marine boundary layer during the First Aerosol Characterization Experiment (ACE 1) and the underlying chemical and physical aerosol properties, J. Geophys. Res.-Atmos., 103(D13), 16 547–16 563, 1998. Quinn, P. K., Coffman, D. J., Bates, T. S., Welton, E. J., Covert, D. S., Miller, T. L., Johnson, J. E., Maria, S., Russell, L., Arimoto, R., Carrico, C. M., Rood, M. J., and Anderson, J.: Aerosol optical properties measured on board the Ronald H. Brown during ACE-Asia as a function of aerosol chemical composition and source region, J. Geophys. Res.-Atmos. 109(D19), D19S01, doi:10.1029/2003JD004010, 2004. Reid, J. S.: Physical and optical properties of young smoke from individual biomass fires in Brazil, J. Geophys. Res.-Atmos., 103(D24), 32 013–32 030, 1998. Saathoff, H., Naumann, K. H., Schnaiter, M., Schock, W., Mohler, O., Schurath, U., Weingartner, E., Gysel, M., and Baltensperger, U.: Coating of soot and (NH4)(2)SO4 particles by ozonolysis products of alpha-pinene, J. Aerosol Sci., 34(10), 1297–1321, 2003. Schmid, O., Artaxo, P., Arnott, W. P., Chand, D., Gatti, L. V., Frank, G. P., Hoffer, A., Schnaiter, M., and Andreae, M. O.: Spectral light absorption by ambient aerosols influenced by biomass burning in the Amazon Basin. I: Comparison and field calibration of absorption measurement techniques, Atmos. Chem. Phys., 6, 3443–3462, 2006. Schnaiter, M.: Measurement of wavelength-resolved light absorption by aerosols utilizing a UV-VIS extinction cell, Aerosol Sci. Technol., 39, 249–260, 2005. Schuster, G. L., Dubovik, O., Holben, B. N.: Angstrom exponent and bimodal aerosol size distributions, J. Geophys. Res.-Atmos., 111, D07207, doi:10.1029/2005JD006328, 2006. Seinfeld, J. and Pandis, S.: Atmospheric Chemistry and Physics: From Air Pollution to Climate Change, New York, John Wiley & Sons, Inc., 1998. Sheridan, P. J. and Ogren, J. A.: Observations of the vertical and regional variability of aerosol optical properties over central and eastern North America, J. Geophys. Res.-Atmos., 104(D14), 16 793–16 805, 1999. Streets, D. G., Bond, T. C., Carmichael, G. R., Fernandes, S. D., Fu, Q., He, D., Klimont, Z., Nelson, S. M., Tsai, N. Y., Wang, M. Q., Woo, J. H., and Yarber, K. F.: An inventory of gaseous and primary aerosol emissions in Asia in the year 2000, J. Geophys. Res.-Atmos. 108(D21), 8809, doi:10.1029/2002JD003093, 2003. Stunder, B.: available at: http://www.arl.noaa.gov/ready-bin/fnl.pl, 1997. Takegawa, N., Miyakawa, T., Kondo, Y., Jimenez, J. L., Zhang, Q., Worsnop, D. R., and Fukuda, M.: Seasonal and diurnal variations of submicron organic aerosol in Tokyo observed using the Aerodyne aerosol mass spectrometer, J. Geophys. Res.-Atmos., 111(D11), D11206, doi:10.1029/2005JD006515, 2006. U.N.: World Urbanization Prospects: The 2005 Revision, available at: http://www.un.org/esa/population/publications/WUP2005/2005WUPHighlights_Final_Report.pdf, 2005. Waggoner, A. P., Weiss, R. E., Ahlquist, N. C., Covert, D. S., Will, S., and Charlson, R. J.: Optical Characteristics of Atmospheric Aerosols, Atmos. Environ., 15(10-1), 1891–1909, 1981. Wang, W., M. Rood, Carrico, C. M., Covert, D. S., Quinn, P. K., and Bates, T. S.: Aerosol optical properties along the northeast coast of North America during the New England Air Quality Study-Intercontinental Transport and Chemical Transformation 2004 campaign and the influence of aerosol composition, J. Geophys. Res., 112, D10S23, doi:10.1029/2006JD007579, 2007. Wei, F., Teng, E., Wu, G., Hu, W., Wilson, W. E., Chapman, R. S., Pau, J. C., and Zhang, J.: Ambient concentrations and elemental compositions of PM$_10$ and PM$_2.5$ in four Chinese cities, Environ. Sci. Technol., 33(23), 4188–4193, 1999. Wiscombe, W. J. and Grams, G. W.: Backscattered Fraction in 2-Stream Approximations, J. Atmos. Sci., 33(12), 2440–2451, 1976. Wu, D., Tie, X. X., Li, C. C., Ying, Z. M., Lau, A. K. H., Huang, J., Deng, X. J., and Bi, X. Y.: An extremely low visibility event over the Guangzhou region: A case study, Atmos. Environ., 39(35), 6568–6577, 2005. Xu, J., Bergin, M. H., Yu, X., Liu, G., Zhao, J., Carrico, C. M., and Baumann, K.: Measurement of aerosol chemical, physical and radiative properties in the Yangtze delta region of China, Atmos. Environ., 36(2), 161–173, 2002.