Evaluation of Precipitation Variability in CMIP5/CMIP6 Models and TaiESM: Do CMIP6 outperform CMIP5?

Variability of precipitation in CMIP5/CMIP6 models and the Taiwan Earth system model (TaiESM) is evaluated in terms of simple daily intensity, maximum 1-day precipitation, extreme precipitation intensity, and diurnal cycle of rainfall. It is found that CMIP6 models do not have substantial improvement comparing to CMIP5. The performance of TaiESM is above average among CMIP6 models, and it is probably associated with the new triggering functions implemented in the deep convection parameterization, which can effectively increase the intensity of convective precipitation. We also examine the characteristics of seasonal precipitation in the East Asia/western North Pacific monsoon region. In general, TaiESM has the best performance among CMIP6 models in simulating extreme precipitation, as well as the evolution and intensity of the monsoon rainband, in summer and autumn.