Abstract:Monthly sea surface temperature (SST) data from HadISST, ocean three-dimensional current velocity and temperature monthly assimilation data from SODAv2.2.4 and monthly surface air temperature (SAT) at 2-m height data from NCEP/NCAR during 1950?2020 in winter are used in this study. Combined with the asymmetric composite difference analysis method and heat budget analysis method, the possible ocean dynamic process of significantly asymmetric SST anomaly caused by ENSO events over eastern (E: 80°?110°W, 10°S?10°N) and central (C: 160°E?170°W, 10°S?10°N) equatorial Pacific has been explored. The asymmetric spatial responses of SAT anomaly at 2-m height under El Ni?o events and La Ni?a events are also analyzed. The results show that the El Ni?o events in the E region are significantly stronger than the La Ni?a events, while the C region is the opposite. The contribution of nonlinear dynamic heating to the asymmetric components of SSTs anomaly in El Ni?o (La Ni?a) years over the E and C regions are the same, and it is the dominant dynamic factor that causes the positive and negative asymmetric components of SSTs anomaly in these two regions. Ekman pumping has a strong negative feedback effect on the positive asymmetric component of SST anomaly in the E region, but has few contributions to the negative asymmetric component of SST anomaly in the C region. The formation of the negative asymmetric component in the C region is damped by zonal advection and thermocline feedback. The SAT anomaly at 2-m height and its asymmetric distribution are consistent with the asymmetric spatial distribution of SST anomaly. However, the significant range of positive and negative asymmetric components of SAT anomaly is significantly reduced, and the asymmetric results in some areas are not significant.