Mengistu, Gizaw (PhD)Moloro, Girma2018-06-262023-11-092018-06-262023-11-092010-07http://10.90.10.223:4000/handle/123456789/3706The RegCM3 rainfall simulations based on the three boundary forcing elds ERA40, ERAIN and NNRP1 have been compared with observational rainfall over Ethiopia for the period from 1989􀀀1999. The RegCM3 simulations are carried out for all three boundary elds with the same horizontal resolution (60 km), domain size and model physics. The performance of RegCM3 in capturing major large scale features, interannual, interseasonal and intraseasonal variability over the simulation period is found to be good. However, the RegCM3 simulation based on ERA􀀀INTERIM has captured the features better than the other two throughout the simulation period. The precipitation from RegCM3 agree well with the observed precipitation in general. Comparison of the simulations carried out using the three forcing elds reveals that simulation of rainfall based on ERA􀀀INTERIM boundary forcing reproduces observed precipitation from CRU dataset better than the other two simulations. ERA40 and NNRP1 simulation have shown a negative rainfall bias compared to the CRU rainfall for some homogeneous regions of EthiopiaenEthiopia to Boundary ForcingThesis