Does the Atmospheric Global Model MRI-AGCM3.2 Perform Better than CMIP6 Atmospheric Models in Simulating Precipitation?
Abstract The performance of the Meteorological Research Institute-Atmospheric General Circulation model version 3.2 (MRI-AGCM3.2) in simulating precipitation is compared with that of global atmospheric models registerred to the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The MRI-AGCM3.2 with the grid size of 20-km and 60-km and 36 CMIP6 models are forced with observed sea surface temperature for 20-year period from 1995 to 2014. The horizontal resolution of the MRI-AGCM3.2 is relatively finer than CMIP6 models. As for global domain, the reproducibility of MRI-AGCM3.2 models are better than or equal to CMIP6 models in simulating geographical distribution of annual precipitation and intense precipitation events. Models with higher horizontal resolution tend to be better than those with lower resolution in simulating global precipitation. As for East Asia, the performance of MRI-AGCM3.2 models are better than or equal to CMIP6 models in simulating summertime monthly precipitation and the seasonal march in the Japanese rainy season, and extreme precipitation events. Higher horizontal resolution models also tend to perform better than lower resolution models in simulating precipitation over East Asia. The advantage of models with higher horizontal resolution over those with lower resolution in reproducing precipitation is more evident over East Asia than over the globe.