Hemispheric warming asymmetry and its contribution to El Niño and Southern Oscillation

Traditional theory treats El Niño event and the subsequent sea temperature oscillation as a self-sustaining process, which is thermodynamically unrealistic, as it overlooks the need for an external energy source. Moreover, current models do not capture key features of the observed Oceanic Niño Index (ONI), making long-term prediction of El Niño events a persistent challenge. This study proposes that hemispheric asymmetry in sea surface warming gives rise to El Niño events. During these events, t