REGIONAL DATA ASSIMILATION SYSTEM OF HUAIHE BASIN EXPERIMENT (HUBEX)

The Regional Data Assimilation System (RDAS) of Huaihe Basin Experiment (HUBEX) is presented. The RDAS is an intermittent assimilation system in which an assimilation cycle includes four analyses in a daily period. Both the first guess fields for the cold starting of the system and the boundary conditions for the assimilation model are supplied by products of the global model system. The RDAS consists of quality control, σ-surface optimum interpolation objective analysis, nudging initialization, mesoscale assimilation model forecast and post-processing. The observational data from the Global Telecommunication System (GTS), HUBEX intensive observation period (IOP) and National Satellite Meteorological Center are assimilated. Finally, a heavy rain process in June 24—28, 1998 is tested using the RDAS.