the ENSO-asymmetry problem.'
address: |
     [Research Institute for ESMD method and Its Applications,]{}\
    [College of science, Qingdao University of Technology, Shandong, China (266520).]{}\
    [E-mail: wangjinliang0811@126.com]{} 
author:
- 'Jin-Liang Wang'
bibliography:
- 'references.bib'
title: 'Current-Generating Mechanism for El Niño & La Niña, an Data Evidence from Integrated ESMD Method[^1]'
---

extreme-point symmetric mode decomposition (ESMD) method,ENSO,El Nino and La Nina,ocean-current generating mechanism ,empirical orthogonal function (EOF) method.

= 18 pt

Introduction
============

El Niño and La Niña events with anomalous warm and cold sea surface temperatures (SSTs) in the tropical Pacific, respectively, are major climate phenomena that are related to extreme weather conditions worldwide (Cai et al. 2015a). The inter-annual oceanic shift between them is usually considered to be a consequence of ocean-atmosphere interactions. Together with the “Southern Oscillation” atmospheric counterpart, defined by the sea-level pressure (SLP), this ocean-atmosphere oscillation is seen to be a self-sustaining cycle dubbed the “El Niño Southern Oscillation (ENSO)” (Enfield 1989; Neelin et al. 1998; Wang and Picaut 2004; Collins et al. 2010). In research, generally “ENSO” has a non-specific meaning; however, in the present article it is used to denote the aforementioned self-sustaining cycle. Relatively, the terms “El Niño” and “La Niña” are only used 