ATOVS data assimilation in two different heavy rainfalls

Based on T213-SSI assimilation system, using ATOVS data from NOAA16, 17, an assimilation experiment was done. Three schemes was used to simulate two cases - the Sichuan and Chongqing heavy rainfall and the Huaihe Basin heavy rainfall. Comparing the different assimilation results draw a conclusion below: Assimilated ATOVS data by T213-SSI system is very useful in heavy rainfall forecasting. By continued assimilation, satellite data can improve Large-scale synoptic situation and the precipitation forecast, especially precipitation intensity. T213-SSI assimilation and forecast system showed more accurate in Huaihe basin than in Sichuan and Chongqing area on heavy rainfall forecast. After assimilation, all weather elements showed a greater improvement in Sichuan and Chongqing area than another. Different area, different rainfall systems need different data assimilation schemes to get a better result. In Huaihe basin, close to the sea, the heavy rainfall caused by frontogenesis with the high-level trough should be removed surface and low level channels data of the AMSU-A in assimilation. Sichuan and Chongqing has a complex terrain, and Qinghai-Tibet Plateau is lack of conventional observation data. So AMSU-A data which include surface and low level channels should be assimilated.