Remote sensing of Asian dust storms

Global environmental changes have become a key issue facing the international community, where variations in the atmospheric environment have received particular attention. The suspended particles in the air, generally called aerosols, are produced either through natural processes or human activities, which deeply affect the air quality. Atmospheric aerosols not only scatter but also absorb significantly the incoming solar radiation within the entire spectrum (Liou 1980). They are also a provider of cloud condensation nuclei that results in the formation of clouds and may thus affect the Earth’s radiation budget and rainfalls. Due to the fact that these suspended particles affect the radiation transfer, the aerosol optical depth (AOD, a measure of aerosol loading), which is an important parameter in the radiation transfer equation, can be used to describe the optical properties of the aerosols. Previous research has shown that the aerosol parameters must be taken into account to obtain a more accurate environmental assessment for the simulations of atmospheric circulations and climate patterns (Hansen and Lacis 1990; Hsu et al. 2000; Hansell et al. 2003). Atmospheric aerosol parameters thus play a pivotal role in accessing the global environmental changes (Liu and Shiu 2001; Li et al. 2004; Gao et al. 2006; Yoshioka et al. 2007).