In future climate prediction, outputs from Global Climate Models (GCMs) have to be downscaled for local prediction due to the coarse resolution of GCMs. In this paper, a dynamical downscaling method to estimate 850hPa geopotential height at 5 specific locations in Thailand is proposed. The dynamic equation is based on temperature lapse rate. The locations are Bangkok, UbonRatchathani, Chiangmai, Phuket and Songkla. Two steps for the dynamical dowscaling consist of using the output from Education Global Climate Model (EdGCM) as the input to the dynamic equation. Then Inverse Distance Weight (IDW) is used for interpolation the outputs from dynamical equation at EdGCM grid points to the 5 locations. The performance of the dynamical downscaling method is determined from the mean absolute error between the estimated geopotential height and observations from meteorological stations at the 5 locations. The results show that dynamical downscaling provides higher accuracy of geopotential height than the direct interpolation from EdGCM.

downscaling, adiabatic lapse rate, inverse distance weight interpolation.