P47  Impacts of Revised Surface-Layer Physics in WRF V3.4 on   Heavy Rainfall Simulations over Korea

Lee, Junhong, Hyeyum Hailey Shin, and Song-You Hong, Yonsei University, Department of Atmospheric Sciences, Seoul, Korea

The objective of this study is to investigate the impacts of surface-layer physics processes that were introduced in WRF V3.4 on heavy rainfall simulations over Korea. One of the revisions was suggested for improving the representation of resolved and unresolved topographic effects on surface wind, by solving a high surface wind speed bias problem over lands. The other is a revised surface layer scheme. This revision includes modified similarity functions that are more suitable under strong stable/unstable conditions and reduces or suppresses the non-physical artificial limits that are imposed on certain variable. WRF version 3.4 is used to verify the impacts of these two schemes in reproducing a heavy rainfall event with local maximum of 339.0 mm and maximum intensity of 77.5 mm h-1 that occurred over Korea, on 11-13 July 2006.