Asian dust: Spatial and optical properties as seen by satellite ocean color sensors

Mineral dust-rich aerosol, such as of Saharan dust or Asian dust, is important in terms of its effect on radiation budget as well as a source of micro-nutrient in the oceanic phytoplankton ecosystem. The authors introduce an empirical scheme for detecting dust aerosol over the ocean using satellite ocean color data such as of Sea Wide Field-of-View Scanner (SeaWiFS) or Ocean Color and Temperature Scanner (OCTS). The dust detection scheme uses estimated aerosol reflectance at 4 bands to detect spectral curvature in the aerosol reflectance. A series of dust index images over the north Pacific is derived from the SeaWiFS data obtained in April, 1998 when major Asian dust events were reported. The satellite-derived dust imagery is compared with the TOMS Aerosol Index imagery as well as the results of a dust transport simulation. The comparison reveals several small-scale differences although their dust distribution patterns show good agreement generally