Simulation of the western North Pacific subtropical high in El Nino decaying summers by CMIP5 AGCMs

The performances of CMIP5 atmospheric general circulation models (AGCMs) in simulating the western North Pacific subtropical high (WNPSH) in El Niño decaying summers are examined in this study. Results show that most models can reproduce the spatial pattern of both climatological and anomalous circulation associated with the WNPSH in El Niño decaying summers. Most CMIP5 AGCMs can capture the westward shift of the WNPSH in El Niño decaying summers compared with the climatological location. With respect to the sub-seasonal variation of the WNPSH, the performances of these AGCMs in reproducing the northward jump of the WNPSH are better than simulating the eastward retreat of the WNPSH from July to August. Twenty-one out of twenty-two (20 out of 22) models can reasonably reproduce the northward jump of the WNPSH in El Niño decaying summers (climatology), while only 7 out of 22 (8 out of 22) AGCMs can reasonably reproduce the eastward retreat of the WNPSH in El Niño decaying summers (climatology). In addition, there is a close connection between the climatological WNPSH location bias and that in El Niño decaying summers.