[Paper Review] On the Nature of the El Nino/La Nina Events

D. H. Douglass, Drew R. Abrams+2 more|ArXiv.org|Mar 7, 2002

Climate variability and models7 references3 citations

TL;DR

This paper proposes a Super-Nino Event model to explain El Niño/La Niña cycles, positing a 15-year oscillatory template that alternates between El Niño and La Niña phases. The model accounts for observed climate phenomena since 1968 through three such events and predicts a minor El Niño peak around mid-2002, with the current event ongoing since the mid-1990s.

ABSTRACT

We propose a scenario that explains many of the Pacific Ocean climate phenomena that are called El Nino/ La Nina. This scenario requires an event, which we call a Super-Nino Event. It dominates other phenomena when it occurs. A template of this event has been constructed giving the time evolution, which is an alternating sequence of 'El Ninos' and 'La Ninas'. The duration of the event is about 15 years unless some other event intervenes. Three such events can explain most of the El Nino/La Nina features that have been observed since 1968. We find that the various El Nino/La Nina features that have been observed fall into types, associated with the oscillation in the template, which can be classified by a "Periodic Table". The Earth is presently experiencing one of these events which started in the mid 1990's and will continue for another 4-5 years. This extrapolation into the future suggests that a minor El Nino will begin in mid 2001 and will reach a maximum about a year later. The conditions under which such a Super Nino-Event may occur are discussed.

Motivation & Objective

• To explain the recurring Pacific Ocean climate phenomena known as El Niño and La Niña through a unified physical model.
• To identify a dominant, long-term oscillatory event—termed the Super-Nino Event—that governs the timing and characteristics of these phenomena.
• To classify observed El Niño/La Niña features into distinct types based on phase within the proposed oscillatory template.
• To provide a predictive framework for future El Niño and La Niña events based on the current phase of the Super-Nino cycle.

Proposed method

• The authors construct a time-evolving template representing a 15-year oscillation between El Niño and La Niña states.
• The model uses observed climate data since 1968 to calibrate and validate the template's phase progression.
• A 'Periodic Table' classification system is developed to categorize observed El Niño/La Niña events by their phase and characteristics within the template.
• The current phase of the Super-Nino Event is determined by comparing observed conditions to the template, extending the timeline into the early 2000s.
• The model assumes that the Super-Nino Event dominates other climate signals when active and persists unless interrupted by another event.

Experimental results

Research questions

• RQ1 What underlying oscillatory mechanism can explain the recurring and alternating nature of El Niño and La Niña events?
• RQ2 How can the observed diversity of El Niño/La Niña features be systematically classified?
• RQ3 What is the duration and phase structure of the dominant climate cycle governing these phenomena?
• RQ4 Can the current phase of the Pacific climate system be predicted using this model?

Key findings

• The Super-Nino Event model explains most observed El Niño/La Niña features since 1968 through three distinct 15-year cycles.
• The Earth is currently in a Super-Nino Event that began in the mid-1990s and is expected to last another 4–5 years.
• A minor El Niño is predicted to begin in mid-2001 and reach its peak intensity about one year later, around mid-2002.
• The observed El Niño and La Niña events fall into distinct types that correspond to specific phases within the proposed 15-year oscillatory template.
• The model's classification system, termed a 'Periodic Table', organizes events based on their phase and characteristics within the oscillation.