中文摘要：

以2003年7月3--4日淮河流域平流型暴雨和2003年8月2～3日江西蒸发型暴雨个例为例，采用模式试验方法，研究了陆面参数化方案对两种不同类型暴雨的模式可预报性的影响。关闭陆气通量的试验表明，陆气通量对淮河流域暴雨的贡献很小，模式预报结果之间的差异较小，平流型暴雨具有较高的模式可预报性；而陆气通量对热对流暴雨的贡献很大，其误差对暴雨的分布和强度影响也较大，蒸发型暴雨的模式可预报性相对较低。不同陆面过程参数化方案的比较试验表明，陆气通量误差引起的能量误差仅在特定区域发展。当陆气通量误差超过一定的临界值，能量误差将在降水区和风速大值区（急流区）迅速发展，能量误差和不稳定能量同源且同时增长。从陆气通量影响天气过程的角度来讲，模式预报启动时间选择在夜间，能量误差发展相对缓慢，可以延长预报时效。

英文摘要：

Through numerical model sensitivity experiments,the impacts of land-surface process parameterization on the model predictability of two heavy rainfall events are studied.The experiments of closing land-air fluxes in the model show that for advective precipitation,such as the severe flood near the Huaihe River basin during 3-4 July 2003,the land-air fluxes contribute little and the model forecast represents small dispersion or relatively high predictability.For evaporative rainfall,such as the shower during 2-3 August 2003,the land-air fluxes contribute much and the model forecast represents large dispersion or relatively low predictability.The experiments of replacing different land processes in the model show that the error growth exhibits selectivity,which only grows rapidly and quickly in the precipitation area and large wind speed（or jet）areas.The errors and instability energy should come from the same origin,and they increase simultaneously.That means model predictability and uncertainty are interlaced.In addition,if the model starts to run at night other than in the daytime,the errors should develop slowly and the predictability time could be prolonged.