| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4439818 | Atmospheric Environment | 2011 | 6 Pages |
Particle number concentrations and size distributions, visibility and particulate mass concentrations and weather parameters were monitored in Brisbane, Australia, on 23 September 2009, during the passage of a dust storm that originated 1400 km away in the dry continental interior. The dust concentration peaked at about mid-day when the hourly average PM2.5 and PM10 values reached 814 and 6460 μg m−3, respectively, with a sharp drop in atmospheric visibility. A linear regression analysis showed a good correlation between the coefficient of light scattering by particles (Bsp) and both PM10 and PM2.5. The particle number in the size range 0.5–20 μm exhibited a lognormal size distribution with modal and geometrical mean diameters of 1.6 and 1.9 μm, respectively. The modal mass was around 10 μm with less than 10% of the mass carried by particles smaller than 2.5 μm. The PM10 fraction accounted for about 68% of the total mass. By mid-day, as the dust began to increase sharply, the ultrafine particle number concentration fell from about 6 × 103 cm−3 to 3 × 103 cm−3 and then continued to decrease to less than 1 × 103 cm−3 by 14 h, showing a power-law decrease with Bsp with an R2 value of 0.77 (p < 0.01). Ultrafine particle size distributions also showed a significant decrease in number during the dust storm. This is the first scientific study of particle size distributions in an Australian dust storm.
► We present the physical characteristics of particles in an Australian dust storm. ► First scientific study of particle size distributions in an Australian dust storm. ► Ultrafine particles in the environment are removed by dust particles. ► A good correlation between light scattering coefficient and both PM10 and PM2.5. ► The PM10 fraction accounted for about 68% of the total mass of dust particles.
