The characteristics of interannual and interdecadal variability of equatorial Pacific Ocean temperature anomalies and ENSO cycle

Based on the simple ocean data assimilation(SODA)data set from the University of Mary land, the characteristics of interannual and interdecadal variability of equat rial Pacific subsurface ocean temperature anomalies(SOTA)w ere analyzed,and its impacts on ENSO cycle were discussed.The results show that,the interannual and interdecadal variabilities of equatorial SOTA have similar spatial distribution and evolution processes as ENSO mode.Both of them have major spatial distribution with the obvious SOTA center in the equatorial western Pacific warm pool and obvious opposite SOTA center in the equatorial eastern Pacific,and then the center in the warm pool propagates east ward and upward along the ocean climatic thermo cline,ENSO events happen when the center reaches east coast of equatorial Pacific.The interannual variability of SOT Ain the equatorial Pacific has decisive effects on the ENSO cycle,it has close relations to nino3 index.The in erdecadal variability of SOT A,which mainly affects on the SOTA in middle equatorial Pacific,also has some important influence on the ENSO cycle,it causes ENSO mode interdecadal variation.When the interdecadal variation is in normal condition,ENSO cycle mainly is the transfer between different types of eastern pattern ENSO events;when the interannual and interdecadal variabilities are in phase,ENSO events will strengthen or occur central pattern events;when the two variabilities are out of phase,ENSO events will weaken.