Characterization of Asian Dust Storms by MTSAT Satellite Retrievals

To characterize the Asian dust storms, an integrated algorithm has been developed to detect dust based on spectral thresholds and uniformity texture tests with Multifunctional Transport Satellite (MTSAT) observations. The thermal radiation transfer and Look-up Tables (LUT) with the assumption of single dust layer was estimated and modeled using SBDART radiative transfer model. The LUTs consisted of six parameters, including aerosol optical thickness (AOT), dust particle effective radius (R _eff ), land surface temperature (LST), dust layer height (Hgt), water vapor (WV) and satellite zenith angle (Uzen). When the other four parameters were controlled, AOT and R _eff were able to be retrieved simultaneously by comparing the brightness temperature (BT) and brightness temperature difference (BTD) in the LUTs with satellite observed BT and BTD. Dust events occurred in 2009 observed by the MTSAT were selected to test the retrieval algorithm. The GEOS-Chem dust model was also used and assisted in identifying the dust transport pathways. Finally, the results were validated with AERONET (AOT and R _eff ) and MODIS AOT data. The retrieved results showed promising agreements with the validation products. This newly developed algorithm provided continuous (both daytime and nighttime) and detailed observations of the dust storms, as well as AOT and particle size information of the dust plumes.