Estimating the greatest dust storm in eastern Australia with MODIS satellite images

On the 23rd of September 2009, Sydney encountered its most severe dust storm in 70 years. The dusts were originated from the Lake Eyre Basin and elevated and swept across the Australian Capital Territory, New South Wales, and Queensland by gusty winds. Ground air quality observation indicated that the dust particle density was 70 times higher than the normal when the dusts struck Sydney. The authors have researched MODIS satellite optical imagery in order to monitor this severe dust storm, and have extracted the information from the satellite images through computing the brightness temperature difference of two thermal infrared channels of MODIS imagery. This method is effective in separating dust and clouds. The mass of the dust plume, therefore, has been estimated using a retrieval model. However, the result of the mass is believed to be under-estimated because the extent of dusts was too great to be covered by a single MODIS image.