Interannual Variability of Tropical Indian Ocean Associated with Indian Ocean Dipole Events Co-occurred with El Niño

The feature and evolution mechanisms of the tropical Indian Ocean (TIO) SST anomalies during Indian Ocean Dipole ocean general circulation model. The vertical heat advection is the major contribution to the peak of southeastern TIO negative SST anomalies. The equatorial western TIO is warmed by surface heat flux, while horizontal and vertical heat advections are responsible for the off-equatorial warming. Then the negative surface heat flux anomalies and the negative vertical heat advection anomalies take over for the cooling of the western and eastern TIO, respectively.