Data assimilation of FY-4A dust aerosol observations for the CUACE/dust forecasting system
<p>A data assimilation system (DAS) was developed&#160;for the Chinese Unified Atmospheric Chemistry Environment&#8211; Dust (CUACE/Dust) forecast system and applied&#160;in the operational forecasts of sand and dust storm (SDS) in&#160;spring in Asia. The system is based on a three dimensional&#160;variational method (3D-Var) and uses extensively the measurements&#160;of surface visibility (phenomena) and dust loading&#160;retrieval from the Chinese geostationary satellite FY-2C.&#160;By a number of case studies, the DAS was found to provide&#160;corrections to both under- and over-estimates of SDS, presenting&#160;a major improvement to the forecasting capability of&#160;CUACE/Dust in the short-term variability in the spatial distribution&#160;and intensity of dust concentrations in both source&#160;regions and downwind areas. &#160;By now The DAS was upgrade to assimilate FY-4A dust&#160;aerosol observations.&#160;The seasonal mean Threat&#160;Score (TS) over the East Asia in spring increased when DAS was used. The forecast results with DAS usually agree with&#160;the dust loading retrieved from FY&#160;and visibility distribution&#160;from surface meteorological stations, which indicates&#160;that the 3D-Var method is very powerful by the unification&#160;of observation and numerical model to improve the performance&#160;of forecast model.</p>