Spectral optical properties of long-range transport Asian dust and pollution aerosols over Northeast Asia in 2007 and 2008 J. Jung1,*, Y. J. Kim1, K. Y. Lee1, M. G. -Cayetano1, T. Batmunkh1, J.-H. Koo2,**, and J. Kim2 1Advanced Environmental Monitoring Research Center (ADEMRC), Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Korea 2Department of Atmospheric Science, Yonsei University, Seoul 120-749, Korea *now at: Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan **now at: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, USA
Abstract. As a part of the IGAC (International Global Atmospheric Chemistry)
Mega-cities program, aerosol physical and optical properties were
continuously measured from March 2007 to March 2008 at an urban site
(37.57° N, 126.94° E) in Seoul, Korea. Spectral optical properties
of long-range transported Asian dust and pollution aerosols have been
investigated based on the year long measurement data. Optically measured
black carbon/thermally measured elemental carbon (BC/EC) ratio showed clear
monthly variation with high values in summer and low values in winter mainly
due to the enhancement of light attenuation by the internal mixing of EC.
Novel approach has been suggested to retrieve the spectral light absorption
coefficient (babs) from Aethalometer raw data by using BC/EC ratio.
Mass absorption efficiency, σabs (=babs/EC) at 550 nm was
determined to be 9.0±1.3, 8.9±1.5, 9.5±2.0, and 10.3±1.7
m2 g−1 in spring, summer, fall, and winter, respectively with an
annual mean of 9.4±1.8 m2 g−1. Threshold values to classify
severe haze events were suggested in this study. Increasing trend of aerosol
single scattering albedo (SSA) with wavelength was observed during Asian
dust events while little spectral dependence of SSA was observed during
long-range transport pollution (LTP) events. Satellite aerosol optical
thickness (AOT) and Hysplit air mass backward trajectory analyses as well as
chemical analysis were performed to characterize the dependence of spectral
optical properties on aerosol type. Results from this study can provide
useful information for studies on regional air quality and aerosol's effects
on climate change.
Citation: Jung, J., Kim, Y. J., Lee, K. Y., -Cayetano, M. G., Batmunkh, T., Koo, J.-H., and Kim, J.: Spectral optical properties of long-range transport Asian dust and pollution aerosols over Northeast Asia in 2007 and 2008, Atmos. Chem. Phys., 10, 5391-5408, doi:10.5194/acp-10-5391-2010, 2010.