Abstract
Based on four reanalyses or gridded data sets (ERA5, 20CR, APHRODITE and
REGEN), we provide an overview of 23 Historical and 7 HighResMIP
experiments’ performance from the Coupled Model Intercomparison Project
Phase 6 (CMIP6) (for short, 6-Hist, HighRes) in simulating seven extreme
precipitation indices over Asia defned by the Expert Team on Climate
Change Detection and Indices (ETCCDI). We compare them with 28
Historical experiments in CMIP5 (5-Hist). CMIP5 and CMIP6 models are
generally able to reproduce extreme precipitation’s spatial distribution
and their trend patterns in comparison to the benchmark data set
(APHRODITE). The overall performance of individual model is summarized
by a “portrait” diagram based on four statistics for each index. We
divide all 58 models into three groups (A, the top 20%; B, the median
60% and C group, the last 20%) according to MR rankings (the
comprehensive ranking measure). Based on the “portrait” diagram and MR
rankings, models that perform relatively well for all seven extreme
precipitation indices include HadCM3, HadGEM2-AO, HadGEM2-CC and
HadGEM2-ES from 5-Hist, EC-Earth3, EC-Earth3-Veg from 6-Hist and
ECMWF-IFSHR, ECMWF-IFS-LR, ECMWF-IFS-MR from HighRes. The simulated
performance of CMIP6 is polarized, for the top four and the last fve
ranking models are both from CMIP6. Compared with the counterpart models
in CMIP6 and CMIP5, the improvement of PCC (pattern correlation
coefcient) is more obvious. Furthermore, the dry biases of CMIP6 (both
6-Hist and HighRes) in Southern China and India and the wet biases of
CMIP6 in Tibet are reduced compared to CMIP5. This may beneft from the
improvement that CMIP6 models can capture the characteristics of
meridional moisture fux convergence, and improve the overestimation or
underestimation of meridional and zonal specifc humidity eddies compared
to CMIP5.