Data assimilation of dust aerosol observations for theCUACE/dust forecasting system

[摘要] A data assimilation system (DAS) was developed for the Chinese UnifiedAtmospheric Chemistry Environment – Dust (CUACE/Dust) forecast system andapplied in the operational forecasts of sand and dust storm (SDS) in spring2006. The system is based on a three dimensional variational method (3D-Var)and uses extensively the measurements of surface visibility (phenomena) and dust loadingretrieval from the Chinese geostationary satellite FY-2C. By a number ofcase studies, the DAS was found to provide corrections to both under- andover-estimates of SDS, presenting a major improvement to the forecastingcapability of CUACE/Dust in the short-term variability in the spatialdistribution and intensity of dust concentrations in both source regions anddownwind areas. The seasonal mean Threat Score (TS) over the East Asia inspring 2006 increased from 0.22 to 0.31 by using the data assimilationsystem, a 41% enhancement. The forecast results with DAS usually agreewith the dust loading retrieved from FY-2C and visibility distribution fromsurface meteorological stations, which indicates that the 3D-Var method isvery powerful by the unification of observation and numerical model toimprove the performance of forecast model.

[学科分类] 大气科学