Numerical Simulation on the Sensitivity of Heavy Rainfall over the Sichuan Basin to Initial Value

By using a regional model named AREM (Advanced Regional Eta-coordinate Model), which was developed by LASG/IAP/CAS, we have simulated and analyzed the heavy rainfall events happened over the Sichuan basin during July 2007.Verifying the predictions initialized with NCEP and the station data respectively shows that the NCEP-initialized has higher score than the other for the observed data in this area is scarce.The analyses reveal that the initial value is crucial to the heavy rainfall events over the Sichuan Basin;not only the intensity, the coverage of heavy rainfall but also the time of maximum precipitation are highly sensitive to the initial value.The sensitivity of every physical quantity field is also discussed in this paper.The initial humidity field has the most obvious influence among them.