6.5 Impact of resolution and boundary conditions on the cloud simulation over Middle East area

Pan, Linlin, Yubao Liu, Yongxin Zhang, Rong-Shyang Sheu, Roux Gregory, National Center for Atmospheric Research, Dorita Rostkier-Edelstein, Svivan Twito, and Pi Adam, Israel Institute for Biological Research, Israel

This study focuses on the impact of resolution and boundary conditions on the cloud simulation over Eastern Mediterranean region with complex terrain and high-contrast climatological-zone distributions. Model for the advanced generation of 4-dimensional weather operational forecasting system was developed recently in NCAR based on NCAR WRF-RTFDDA (real-time four dimensional data assimilation). Three nested domains, with 9, 3 and 1 km grid intervals, respectfully, are applied in modeling system, and it is centered over Israel. This research investigates the high-resolution performance of the new system on the low cloud simulation through comparisons with that of low-resolution (3km). The impacts of different boundary conditions are also investigated. It is demonstrated that the 1km high-resolution model appears to be able to show better structure in RH fields relative to low clouds than the 3km resolution model does. GFS boundary condition is drier than that of ECMWF during the study period and may leads to dryer PBL and less low cloud condition.