Evaluation of Southwest Monsoon Change over Thailand by High-resolution Regional Climate Model under High RCP Emission Scenario

Abstract

The 5×5 km resolution of Non-Hydrostatic Regional Climate Model (NHRCM) developed by Meteorological Research Institute, Japan was used to evaluate the southwest monsoon season that affects to Thailand during mid-May until mid-October in each years. Bulk-type cloud microphysics, Kain-Fritsch convective scheme, Mellor-Yamada-Nakanishi-Niino level 3 PBL scheme, clear-sky radiation scheme and Hirai-Ohizumi land surface scheme are used as model configuration to simulate climate data under high emission scenario-RCP 8.5. This research was conducted for 2 time periods, i.e., baseline period (1981-2000) and future period (2080-2099), to estimate the southwest monsoon season onset and offset over Thailand by using average wind vector and cumulative precipitation in consecutive 5 days (pentad). Furthermore, the rain-break phase, less precipitation ranges during the southwest monsoon season, had also been analysed.