[A-AS05] Large-scale moisture and organized cloud systems

[AAS05-05] Topographic and resolution impact on the convection over the Philippine islands

*Yoshiyuki Kajikawa^1,2, Tsuyoshi Yamaura² (1.Research Center for Urban Safety and Security, Kobe University, 2.RIKEN Center for Computational Science)

Keywords:Convection, Islands, Topography, Resolution

Philippine islands are located in the convection center driving the general circulation during boreal summer. Of great importance is to represent the convection over the Philippines accurately in the global circulation model. Since the Philippines are characterized by many small islands and precipitous mountains, it is worthwhile to figure out the necessary resolution and process for better simulating the convection in the model. In this study, we conducted the sensitivity experiments of the convections over the Philippines during boreal summer to examine the impact of (1) horizontal resolution and (2) topography by using SCALE-RM (http://r-ccs-climate.riken.jp/scale/index.html); we adopted 45km and 25km resolution and set up the 25km atmosphere resolution with 45km resolution topography. Each experiment is integrated 10 years as a preliminary experiment. The results indicate that the total precipitation amount increase with higher horizontal resolution. The impact of topography is larger in the precipitation produced by Microphysics anchored in steep mountains. On the other hand, higher horizontal resolution affects less precipitation over the South China sea produced by cumulus parameterization (Kain-Fitch scheme). Intensified tropical cyclones and newly generated tropical disturbance in the simulation with higher atmospheric resolution contribute to the increase of precipitation over the Philippines. The effects of the calculation domain size will be also discussed.