Application of Doppler Radar Data Assimilation in a Local Rainstorm Case in Gansu Province

Based on the diagnosis analysis of a local rainstorm event in Gansu Province on 27 July 2006,using a series of comparative experiments by direct assimilation Doppler radar wind data method,the Grapes numerical model and its data assimilation system,the role of Doppler radar data assimilation in simulating the local rainstorm case is studied.The results show that the application of Doppler radar data assimilation in numerical model can obviously improve the ability of model to simulate the mesoscale and microscale weather systems,especially,it can make the fine characteristics of meso-and micro-scale weather systems more distinct and reasonable.And after joining Doppler radar wind data assimilation,wind field convergence characteristics in rainfall area is more apparent,wind speed also has certain enhancement,rainfall intensity and center closer to real values.