Evaluating SINGV-RCM for Long-Term High-Resolution Climate Simulations Over Southeast Asia

Abstract

Long-term convection-permitting dynamical downscaling has been carried out over Southeast Asia and the Western Maritime Continent, using the Singapore Regional Climate Model (SINGV-RCM) at 8 and 2 km spatial resolutions, respectively. SINGV-RCM is forced with ERA5 reanalysis data for 36 years (1979–2014) at 8 km resolution over Southeast Asia (79E-160E; 16S-24N) with a regular update of the sea surface temperature at 6-h intervals. Subsequently, the 8 km domain simulation is used for forcing a smaller domain over the Western Maritime Continent at a resolution of 2 km (93E-110E; 7.2S-9.9N) for 20 years (1995–2014). Rainfall characteristics including the diurnal cycle, monthly annual cycle, and daily extremes over land and ocean from the two simulations are evaluated against the high-resolution IMERG precipitation data available from 2001 to 2014. SINGV-RCM captures mean and extreme rainfall well; however, there are noticeable biases in the rainfall magnitude over the Ocean. These biases agree with the earlier publications on convection-permitting simulation over the maritime Continent. Models' skill is further evaluated in terms of mean, bias, pattern correlation and RMSE for 8 and 2 km simulations against the IMERG precipitation data.