References

ACPD

Atmospheric Chemistry and Physics Discussions

ACPD

1680-7375

Copernicus GmbH

Göttingen, Germany

10.5194/acpd-9-8341-2009

Study of columnar aerosol size distribution in Hong Kong

Yang

¹ Wenig

Laboratory for Atmospheric Research, Department of Physics and Materials Science, City University of Hong Kong, Hong Kong, China

30 03 2009

9 2 8341 8375

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-discuss.net/9/8341/2009/acpd-9-8341-2009.html

The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/9/8341/2009/acpd-9-8341-2009.pdf

This paper presents studies on columnar aerosol optical properties in Hong Kong with focus on aerosol volume size distribution. Long-term ground measurements in the wet season in the years of 2002, 2003, 2004 and 2008 have been performed using a sun-sky radiometer. A bimodal size distribution is found with the fine mode centering at ~0.2 μm and coarse mode centering at ~6 μm, respectively. The fine and coarse mode have close volume concentrations of nearly 50% fraction in composing local aerosols. Intercomparison of different years shows similar aerosol properties while a small increase of fine mode aerosol could be observed. A systematic shift of size distribution parameters is observed with different atmospheric conditions, where higher aerosol loadings and Angstrom exponent correspond to more fine aerosols. The fine mode is found to be more closely correlated with this shift than the coarse mode. A higher fine mode volume fraction and smaller median fine radius correspond to a larger Angstrom exponent. The fine aerosol hygroscopic growth is one of the main mechanisms for such systematic shifting. A third mode centering at ~1–2 μm could be discovered under high aerosol loading and high fine aerosol conditions. It becomes more pronounced with high aerosol optical depth and larger Angstrom exponent. Investigation of its variation with corresponding optical parameters and correlation with atmospheric conditions indicates that it is mainly due to the fine aerosol hygroscopic growth and coagulation rather than the contribution from the coarse mode. While the very humid environment facilitates the aerosol hygroscopic growth, aerosol coagulation might further produce more large aerosols under high fine aerosol conditions. The continental outflow with transported ageing aerosols and biomass burning might have also contributed to this additional mode.

References 1

Andreae,~M O.: The dark side of aerosols, Nature, 409, 671–672, 2001.

Angstrom,~A.: On the atmospheric transmission of sun radiation and on dust in the air, Geogr. Ann., 11, 156–166, 1929.

Boi,~P., Tonna,~G., Dalu,~G., Nakajima,~T., Olivieri,~B., Pompei,~A., Campanelli,~M., and Rao,~R.: Calibration and data elaboration procedure for sky irradiance measurements, Appl. Opt., 38, 896–907, 1999.

Campanelli,~M., Estelles,~V., Tomasi,~C., Nakajima,~T., Malvestuto,~V., and Martinez-Lozano,~J A.: Application of the SKYRAD Improved Langley plot method for the in situ calibration of CIMEL Sun-sky photometers, Appl. Opt., 46, 2688–2702, 2007.

Carmine,~C D., Campanelli,~M., Nakajima,~T., Tomasi,~C., and Vitale,~V.: Retrievals of antarctic aerosol characteristics using a~Sun-sky radiometer during the 2001–2002 austral summer campaign, J. Geophys. Res., 110, D13202, doi:10.1029/2004JD005280, 2005.

Chan,~C Y., Chan,~L Y., Harris,~J M., Oltmans,~S J., Blake,~D R., Qin,~Y., Zheng,~Y G., and Zheng,~X D.: Characteristics of biomass burning emission sources, transport, and chemical speciation in enhanced springtime tropospheric ozone profile over Hong Kong, J. Geophys. Res., 108, 4015, doi:10.1029/2001JD001555, 2003.

Chan,~L., Chan,~C., Liu,~H., Christopher,~S., Oltmans,~S., and Harris,~J.: A~case study on the biomass burning in Southeast Asia and enhancement of tropospheric ozone over Hong Kong, Geophys. Res. Lett., 27, 1479–1482, 2000.

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., 111, D12310, doi:10.1029/2005JD006663, 2006.

Chu,~D A., Kaufman,~Y J., Zibordi,~G., Chern,~J D., Mao,~J., Li,~C., and Holben,~B N.: Global monitoring of air pollution over land from the Earth Observing System-Terra Moderate Resolution Imaging Spectroradiometer (MODIS), J. Geophys. Res., 108, 4661, doi:10.1029/2002JD003179, 2003.

Cohen,~D D., Garton,~D., Stelcer,~E., Hawas,~O., Wang,~T., Poon,~S., Kim,~J., Choi,~B C., Oh,~S N., Shin,~H.-J., Ko,~M Y., and Uematsu,~M.: Multielemental analysis and characterization of fine aerosols at several key ACE-Asia sites, J. Geophys. Res., 109, D19S12, doi:10.1029/2003JD003569, 2004.

Dubovik,~O. and King,~M D.: A~flexible inversion algorithm for retrieval of aerosol optical properties from Sun and sky radiance measurements, J. Geophys. Res., 105, 20673–20696, 2000.

Dubovik,~O., Holben,~B N., Eck,~T F., Smirnov,~A., Kaufman,~Y J., King,~M D., Tanré,~D., and Slutsker,~I.: Variability of absorption and optical properties of key aerosol types observed in worldwide locations, J. Atmos. Sci., 59, 590–608, 2002.

Eck,~T F., Holben,~B N., Ward,~D E., Dubovik,~O., Reid,~J S., Smirnov,~A., Mukelabai,~M M., Hsu,~N C., O'Neill,~N T., and Slutsker,~I.: Characterization of the optical properties of biomass burning aerosols in zambia during the 1997 ZIBBEE field campaign, J. Geophys. Res., 106, 3425–3448, 2001.

Eck,~T F., Holben,~B N., Reid,~J S., O'Neill,~N T., Schafer,~J S., Dubovik,~O., Smirnov,~A., Yamasoe,~M A., and Artaxo,~P.: High aerosol optical depth biomass burning events: A~comparison of optical properties for different source regions, Geophys. Res. Lett., 30, 2035, doi:10.1029/2003GL017861, 2003a.

Eck,~T F., Holben,~B N., Ward,~D E., Mukelabai,~M M., Dubovik,~O., Smirnov,~A., Schafer,~J S., Hsu,~N C., Piketh,~S J., Queface,~A., Roux,~J L., Swap,~R J., and Slutsker,~I.: Variability of biomass burning aerosol optical characteristics in southern Africa during the SAFARI 2000 dry season campaign and a~comparison of single scattering albedo estimates from radiometric measurements, J. Geophys. Res., 108, 8477, doi:10.1029/2002JD002321, 2003b.

Eck,~T F., Holben,~B N., Dubovik,~O., Smirnov,~A., Goloub,~P., Chen,~H B., Chatenet,~B., Gomes,~L., Zhang,~X.-Y., Tsay,~S.-C., Ji,~Q., Giles,~D., and Slutsker,~I.: Columnar aerosol optical properties at AERONET sites in central eastern Asia and aerosol transport to the tropical mid-Pacific. J. Geophys. Res., 110, D06202, doi:10.1029/2004JD005274, 2005.

Eck,~T F., Holben,~B N., Reid,~J S., Sinyuk,~A., Dubovik,~O., Smirnov,~A., Giles,~D., O'Neill,~N T., Tsay,~S.-C., Ji,~Q., Al Mandoos,~A., Ramzan Khan,~M., Reid,~E A., Schafer,~J S., Sorokine,~M., Newcomb,~W., and Slutsker,~I.: Spatial and temporal variability of column-integrated aerosol optical properties in the southern Arabian Gulf and United Arab Emirates in summer, J. Geophys. Res., 113, D01204, doi:10.1029/2007JD008944, 2008.

Heald,~C L., Jacob,~D J., Palmer,~P I., Evans,~M J., Sachse,~G W., Singh,~H B., and Blake,~D R.: Biomass burning emission inventory with daily resolution: Application to aircraft observations of Asian outflow, J. Geophys. Res., 108, 8811, doi:10.1029/2002JD003082, 2003.

Hess,~M., Koepke,~P., and Schult,~I.: Optical properties of aerosols and clouds: The software package OPAC, B. Am. Meteorol. Soc., 79, 831–844, 1998.

Highwood,~E J., Haywood,~J M., Silverstone,~M D., Newman,~S M., and Taylor,~J P.: Radiative properties and direct effect of Saharan dust measured by the C-130 aircraft during Saharan Dust Experiment (SHADE): 2. Terrestrial spectrum, J. Geophys. Res., 108, 8578, doi:10.1029/2002JD002552, 2003.

Holben,~B N., Eck,~T F., Slutsker,~I., Tanré,~D., Buis,~J P., Setzer,~A., Vermote,~E., Reagan,~J A., Kaufman,~Y J., Nakajima,~T., Lavenu,~F., Jankowiak,~I., and Smirnov,~A.: AERONET – a~federated instrument network and data archive for aerosol characterization, Remote Sens. Environ., 66, 1–16, 1998.

Holben,~B N., Tanré,~D., Smirnov,~A., Eck,~T F., Slutsker,~I., Abuhassan,~N., Newcomb,~W W., Schafer,~J S., Chatenet,~B., Lavenu,~F., Kaufman,~Y J., Castle,~J V., Setzer,~A., Markham,~B., Clark,~D., Frouin,~R., Halthore,~R., Karneli,~A., O'Neill,~N T., Pietras,~C., Pinker,~R T., Voss,~K., and Zibordi,~G.: An emerging ground-based aerosol climatology: Aerosol optical depth from AERONET, J. Geophys. Res., 106, 12067–12097, 2001.

Huebert,~B J., Bates,~T., Russell,~P B., Shi,~G., Kim,~Y J., Kawamura,~K., Carmichael,~G., and Nakajima,~T.: An overview of ACE-Asia: Strategies for quantifying the relationships between Asian aerosols and their climatic impacts, J. Geophys. Res., 108, 8633, doi:10.1029/2003JD003550, 2003.

Ichoku,~C., Chu,~D A., Mattoo,~S., Kaufman,~Y J., Remer,~L A., Tanré,~D., Slutsker,~I., and Holben,~B N.: A~spatio-temporal approach for global validation and analysis of MODIS aerosol products, Geophys. Res. Lett., 29(12), 8006, doi:10.1029/2001GL013206, 2002.

Intergovernmental Panel on Climate Change. Climate Change 2007:~The Physical Science Basis, Cambridge Univ. Press, Cambridge, UK, 2007.

Kaufman,~Y J.: Aerosol optical thickness and atmospheric path radiance, J. Geophys. Res., 98, 2677–2692, 1993.

Kaufman,~Y J., Gitelson,~A., Karnieli,~A., Ganor,~E., Fraser,~R S., Nakajima,~T., Mattoo,~S., and Holben,~B N.: Size distribution and scattering phase function of aerosol particles retrieved from sky brightness measurements, J. Geophys. Res., 99, 10341–10356, 1994.

Kaufman,~Y J., Tanré,~D., Remer,~L A., Vermote,~E F., Chu,~A., and Holben,~B N.: Operational remote sensing of tropospheric aerosol over land from EOS moderate resolution imaging spectroradiometer, J. Geophys. Res., 102, 17051–17067, 1997.

Kaufman,~Y J., Smirnov,~A., Holben,~B N., and Dubovik,~O.:~Baseline maritime aerosol: Methodology to derive the optical thickness and scattering properties, Geophys. Res. Lett., 28, 3251–3254, 2001.

Kaufman,~Y J., Tanré,~D., and Boucher,~O.: A~satellite view of aerosols in the climate system, Nature, 419, 215–223, 2002.

Kaufman,~Y J., Boucher,~O., Tanré,~D., Chin,~M., Remer,~L A., and Takemura,~T.: Aerosol anthropogenic component estimated from satellite data. Geophys. Res. Lett., 32, L17804, doi:10.1029/2005GL023125, 2005.

Kim,~D.-H., Sohn,~B.-J., Nakajima,~T., Takamura,~T., Takemura,~T., Choi,~B.-C., and Yoon,~S.-C.: Aerosol optical properties over east Asia determined from ground-based sky radiation measurements, J. Geophys. Res., 109, D02209, doi:10.1029/2003JD003387, 2004.

Kleidman,~R G., O'Neill,~N T., Remer,~L A., Kaufman,~Y J., Eck,~T F., Tanré,~D., Dubovik,~O., and Holben,~B N.: Comparison of Moderate Resolution Imaging Spectroradiometer (MODIS) and Aerosol Robotic Network (AERONET) remote-sensing retrievals of aerosol fine mode fraction over ocean, J. Geophys. Res., 110, D22205, doi:10.1029/2005JD005760, 2005.

Levy,~R C., Remer,~L A., Mattoo,~S., Vermote,~E F., and Kaufman,~Y J.: Second-generation operational algorithm: Retrieval of aerosol properties over land from inversion of Moderate Resolution Imaging Spectroradiometer spectral reflectance, J. Geophys. Res., 112, D13211, doi:10.1029/2006JD007811, 2007.

Nakajima,~T., Tonna,~G., Rao,~R Z., Boi,~P., Kaufman,~Y J., and Holben,~B N.: Use of sky brightness measurements from ground for remote sensing of particulate polydispersions, Appl. Optics, 35, 2672–2686, 1996.

Nakajima,~T., Sekiguchi,~M., Takemura,~T., Uno,~I., Higurashi,~A., Kim,~D., Sohn,~B J., Oh,~S.-N., Nakajima,~T Y., Ohta,~S., Okada,~I., Takamura,~T., and Kawamoto,~K.: Significance of direct and indirect radiative forcings of aerosols in the East China Sea region, J. Geophys. Res., 108, 8658, doi:10.1029/2002JD003261, 2003.

O'Neill,~N T., Ignatov,~A., Holben,~B N., and Eck,~T F.: The lognormal distribution as a~reference for reporting aerosol optical depth statistics; empirical tests using multi-year, multi-site AERONET sunphotometer data, Geophys. Res. Lett., 27, 3333–3336, 2000.

O'Neill,~N T., Eck,~T F., Holben,~B N., Smirnov,~A., Dubovik,~O., and Royer,~A.: Bimodal size distribution influences on the variation of Angstrom derivatives in spectral and optical depth space, J. Geophys. Res., 106, 9787–9806, 2001.

O'Neill,~N T., Eck,~T F., Smirnov,~A., Holben,~B N., and Thulasiraman,~S.:~Spectral discrimination of coarse and fine mode optical depth, J. Geophys. Res., 108, 4559, doi:10.1029/2002JD002975, 2003.

Reid,~J S., Hobbs,~P V., Ferek,~R J., Blake,~D R., Martins,~J V., Dunlap,~M R., and Liousse,~C.: Physical, chemical, and optical properties of regional hazes dominated by smoke in Brazil, J. Geophys. Res., 103, 32059–32080, 1998.

Reid,~J S., Eck,~T F., Christopher,~S A., Hobbs,~P V., and Holben,~B N.: Use of the Angstrom exponent to estimate the variability of optical and physical properties of aging smoke particles in Brazil, J. Geophys. Res., 104, 27473–27489, 1999.

Remer,~L A., Kaufman,~Y J., Tanré,~D., Mattoo,~S., Chu,~D A., Martins,~J V., Li,~R R., Ichoku,~C., Levy,~R C., Kleidman,~R G., Eck,~T F., Vermote,~E., and Holben,~B N.: The MODIS aerosol algorithm, products, and validation, J. Atmos. Sci., 62, 947–973, 2005.

Schafer,~J S., Eck,~T F., Holben,~B N., Artaxo,~P., and Duarte,~A F.: Characterization of the optical properties of atmospheric aerosols in Amaznia from long-term AERONET monitoring (1993–1995 and 1999–2006). J. Geophys. Res., 113, D04204, doi:10.1029/2007JD009319, 2008.

Schuster,~G L., Dubovik,~O., and Holben,~B N.: Angstrom exponent and bimodal aerosol size distributions. J. Geophys. Res., 111, D07207, doi:10.1029/2005JD006328, 2006.

Singh,~R P., Dey,~S., Tripathi,~S N., Tare,~V., and Holben,~B.: Variability of aerosol parameters over Kanpur, northern India, J. Geophys. Res., 109, D23206, doi:10.1029/2004JD004966, 2004.

Smirnov,~A., Holben,~B N., Eck,~T F., Dubovik,~O., and Slutsker,~I.: Cloud-screening and quality control algorithms for the AERONET database, Remote Sens. Environ., 73, 337–349, 2000.

Smirnov,~A., Holben,~B N., Kaufman,~Y J., Dubovik,~O., Eck,~T F., Slutsker,~I., Pietras,~C., and Halthore,~R N.: Optical properties of atmospheric aerosol in maritime environments, J. Atmos. Sci., 59, 501–523, 2002.

Smirnov,~A., Holben,~B N., Dubovik,~O., Frouin,~R., Eck,~T F., and Slutsker,~I.: Maritime component in aerosol optical models derived from Aerosol Robotic Network data, J. Geophys. Res., 108, 4033, doi:10.1029/2002JD002701, 2003.

Tang,~I N.: Chemical and size effects of hygroscopic aerosols on light scattering coefficients, J. Geophys. Res., 101, 19245–19250, 1996.

Tonna,~G., Nakajima,~T., and Rao,~R.: Aerosol features retrieved from solar aureole data – a~simulation study concerning a~turbid atmosphere, Appl. Optics, 34, 4486–4499, 1995.

Wang,~T., Ding,~A J., Blake,~D R., Zahorowski,~W., Poon,~C N., and Li,~Y S.: Chemical characterization of the boundary layer outflow of air pollution to Hong Kong during February–April 2001, J. Geophys. Res., 108, 8787, doi:10.1029/2002JD003272, 2003.

Zheng,~M., Kester,~D R., Wang,~F., Shi,~X., and Guo,~Z.: Size distribution of organic and inorganic species in Hong Kong aerosols during the wet and dry seasons, J. Geophys. Res., 113, D16303, doi:10.1029/2007JD009494, 2008.