Blue reflectances contrast of MODIS imagery: Implication for dust and biomass burned smoke detection

Using MODIS data over China for the 2000-2008 period, we performed a statistical analysis of the apparent reflectance difference of two blue bands (BRD) between the 469nm and 415nm over ocean and land. The results showed that the BRD gives a discrimination of heavy biomass burned smoke and dust from others phenomena such as cloud, snow/ice, haze and clear-sky surface. It indicates that the MODIS blue bands contrast provides a potentially simple approach for identification of heavy smoke and dust. This method was applied to detect dust storms over several major dust sources region, including the Gobi Desert, the Red Sea and Afghanistan, and fire smoke over Southeastern Siberia and Alaska. The results showed that comparisons of “blue contrast” are consistent with the aerosol thickness retrieval.