Abstract
To demonstrate the importance of regional climate models over Japan, performance of the Meteorological Research Institute Regional Climate Model (MRI-RCM) was compared to the results of a super-high-resolution atmosphere general circulation model whose grid interval was 20 km (GCM20). The grid intervals (20 km) of the models are almost the same. Although both models reproduced the observed annual fluctuation of temperature adequately, the reproduced temperature of the GCM20 was somewhat lower than the observation, especially in winter. The temperature of the GCM20 has a negative bias of about -0.7°C, while the MRI-RCM has a negative bias of -0.1°C. Both models adequately reproduced the precipitation distribution during the winter monsoon. However, the precipitation of the GCM20 is less than the observation in early summer to autumn, while the MRI-RCM adequately reproduced precipitation during the same season. Therefore, for surface temperature and precipitation, the reproducibility of the MRI-RCM is generally better than that of the GCM20.
