1. My recent research interest focuses on the equatorial upwelling and the associated cold tongue sea surface temperature (SST) evolution. My study (Wang et al., 2017b) demonstrated that the semi-annual harmonic bias in the eastern upwelling simulated in Coupled Model Intercomparison Phase 5 (CMIP5) (c) is found to be attributable to the dynamic amplification to the wind-driven wave upwelling (b) originated from a less significant bias in the semi-annual harmonic component in the central equatorial wind field (a). This tells us the realistic simulations of equatorial upwelling, which plays a vital role in the development of cold tongue SST, sensitively depend on good simulations of equatorial wind field.