Understanding the Warm Water Volume Precursor of ENSO events

This thesis has improved understanding on the predictability of the El Niño- Southern Oscillation (ENSO) – a climatic phenomenon in the tropical Pacific region which occurs every 2-7 years. These events can have devastating socioeconomic consequences on a near-global scale. Interestingly, although researchers were previously able to predict such events 9 months in advance, since the year 2000, this capacity has reduced to only 3 months. This thesis has found evidence that this shortened ENSO predictability time results from post-2000 changes in winds affecting the physical dynamics in the tropical Pacific Ocean in a different way compared to the pre-2000 period.