A Sensitivity of SUB-GRID Scale Cumulus Parameterization Effects to Horizontal Resolution
Guo Xiaorong Zheng Guoan Zhu Qi(National Meteorological Center, State Meteorological Administration, Beijing, 100081)
The sensitivity of the parameterization of sub-grid scale convective effects to the horizontal resolution were tested with a 5- level nested limited area model. The results show that the contribution of sub-grid scale convective condensation to precipitation decreases remarkably with the increase of horizontal resolution . The convective precipitation is 60- 70% of the total precipitation in the 381km grid model, and only 10% in the 47.625km grid model . It seems that a numerical model , whose grid length is much smaller than the scale of the forecast system , would satisfactorily simulate the precipitation amounts only by the resolvable scale condensation.