Evaluation of CMIP5 coupled atmosphere–ocean general circulation models and projection of the Southeast Asian winter monsoon in the 21st century

The Southeast Asian ( SEA ) winter monsoon (December–February) precipitation simulation and the potential future climate changes may bring about under different representative concentration pathways ( RCPs ) were evaluated using ten coupled atmosphere–ocean general circulation models ( AOGCMs ) in the fifth phase of the Coupled Model Intercomparison Project ( CMIP5 ). Although all the models simulated the broad features of winter monsoon precipitation spatial patterns, the spread of the bias magnitudes was very large across the AOGCMs . All the models simulated the relationship between the regional rainfall and circulation associated with El Niño‐Southern Oscillation ( ENSO ). However, the strength of the association tended to be weaker in the simulations, ensuing a generally weaker winter monsoon rainfall interannual variability. Three AOGCMs , namely CNRM‐CM5 , NorESM1 ‐M and IPSL‐CM5A‐MR , that simulated the most realistic present‐day climate, were used for examination of future climate projection based on the RCP 2.5, RCP 4.5 and RCP 8.5 scenarios. The projections showed a gradual increment of SEA winter monsoon rainfall under all the scenarios with the highest changes in the RCP 8.5 scenario. The increment was manifested as a zonal band of positive anomalies located at ∼10°N and ∼5°S, indicating northward and southward expansion of the intertropical convergence belt. Between these bands of increasing rainfall, the equatorial South China Sea ( SCS ) area was projected to be slightly drier. The projected increase of rainfall appeared to be associated with the prevailing of cyclonic anomalies over the centre SCS , which promote enhance moisture convergence over this region in the warmer climate.