A new North Pacific climate paradigm and its implication on the 2015 El Niño and ENSO 
prediction / 曾于恆 教授（台大海洋所）


A new Pacific climate paradigm was recently proposed based on the two dominant coupled 
ocean-atmosphere (O–A) modes of surface variability and equatorial dynamics. These two 
leading modes can explain most of the North Pacific climate variability and are linked 
with each other. The second O–A mode reflects the footprint of the meridional 
variability associated with North Pacific Oscillation through the 
tropical–extratropical teleconnection and commonly evolves into the El Niño–Southern 
Oscillation (ENSO) phase. This is confirmed by the occurrence of the warm Blob that 
developed after late 2013 in the northeastern Pacific, leading to the 2015 El Niño. 
Based on the new paradigm, a simple statistical model is derived to enhance the ENSO 
prediction through the evolution of the ocean heat condition and the oceanic Kelvin 
wave propagation associated with westerly wind events and easterly wind surges in the 
tropical Pacific. The hindcast skill of the proposed model is better than that based on 
the Warm Water Volume index in terms of the monthly correlation, normalized RMSEs and 
ENSO occurrences, The hindcast skill is also comparable to the predictions using other 
dynamical and statistical models, indicating that these processes are the keys to ENSO 
development.