Simulation of Rainfall over Bangladesh Using Regional Climate Model (RegCM4.7)

Regional climate model is a scientific tool to monitor present change and provide reliable estimation of future projection. In this study, the Climate Model version 4.7 (RegCM4.7) developed by International Centre for Theoretical Physics (ICTP) has been adopted simulate rainfall scenario Bangladesh. The study examines performance simulation through period 1991-2018 with ERA-Interim75 data 75 km horizontal resolution as lateral boundaries, downscaled at 25km using mixed convective precipitation scheme; MIT-Emanuel scheme over land Grell Fritsch-Chappell closure ocean. simulated compared both spatial temporal scales (monthly, seasonal annual) observed collected from Bangladesh Meteorological Department (BMD) Research Unit (CRU). Simulated annual showed that overestimated in most years. Overestimation monsoon underestimation pre-monsoon post-monsoon seasons. Spatial distribution depicts overestimation southeast coastal region northwest northeast border regions Better found central eastern parts country. validated Linear Scaling bias correction method years 2016, 2017, 2018 considering 1991-2015 reference. linear scaling gives fairly satisfactory results it can be considered projection