Abstract for presentation at 14th IUAPPA World Congress

Size-resolved Properties of Atmospheric Aerosols in Sydney and Regional NSW

  • Taleb Hallal, University of New South Wales, Australia
  • Gail Box, University of New South Wales, Australia
  • Majed Radhi, University of New South Wales, Australia
  • A/Prof Michael Box, University of New South Wales, Australia
  • Dr David Cohen, Australian Nuclear Science and Technology Organisation (ANSTO), Australia
  • Eduard Stelcer, Australian Nuclear Science and Technology Organisation (ANSTO), Australia

    • In recent years it has become evident that size-resolved chemical composition of atmospheric aerosols is important in determining optical properties such as refractive index, scattering and absorption coefficients, extinction and hygroscopicity. These properties affect the way radiation is scattered and absorbed as it passes through the atmosphere, and thus are important for the calculation of aerosol radiative forcing and "atmospheric correction" of satellite images, as well as local air quality and visibility.
    We report results from a study of the size-resolved chemistry of atmospheric aerosols in Sydney and regional NSW, and their relationship to optical properties. PM2.5 and PM10 samples were collected at four sites during the summer, autumn, winter and spring of 2003. These were analysed using Ion Beam Analysis (IBA) and selected samples have also been analysed by Scanning Electron Microscopy (SEM). The elemental chemistry, in combination with meteorological parameters and a chemical thermodynamic model, was then used to determine the aerosol refractive index for each of the sites and size fractions. IBA results show seasonal differences within sites and between sites, as well as differences between PM2.5 and PM10 composition at particular sites. Refractive index values also show seasonal and spatial differences.
    Further PM2.5 and PM10 measurements were made during winter 2006 in Sydney, and Wagga Wagga in regional NSW. A second set of measurements, including using a 10-stage MOUDI sampler for better size-resolution of the chemistry, will be taken at these sites in summer 2007 and similarly analysed.

    Conference Organiser - ICMS Pty Ltd