Towards Understanding El Niño Complexity and Change

Abstract:

ENSO exhibits rich variations in its intensity, its timescales and spatial patterns in sea surface temperature (SST) anomalies and other associated fields. Different ENSO features of the so-called central Pacific and eastern Pacific ENSO types, and the existence of ENSO combination-mode which comes from ENSO and annual-cycle interaction but has its own distinct time-space features, all contributed to the ENSO complexity. Another major source of ENSO complexity comes from the multiple sources of forcing or excitations for ENSO. This talk will briefly review and discusses dynamic frameworks and recent progresses in understanding the basic dynamics for ENSO and ENSO change. We will also discuss the roles of so-called forcing in exciting El Nino events, the roles of the annual cycle and ENSO interaction in generating rich ENSO timescales.