Variety of El Nino and La Nina in the 2oth Century

The El Nino/La Nina cycle is the dominant one among all interannual oscillations in the climate system. It has been studied with data analysis, modeling and other approaches. Before we attemp to explain the mechanism that brings up the El Nino and La Nina, we found that they appear with different life cycles and in several ocean basins.

El Nino and La Nina affect the global winter weather significantly. People have tried to forecast the regional weather based on the El Nino/La Nina cycle. However, most people have already found out that every El Nino/La Nina is unique. We can't assume that the general circulation patterns in two winters will be similar merely because they are both in the El Nino years.

Since every El Nino has a unique characteristics, we assume each undergoes a different life cycle which appears over different ocean basin. We examined a long time series (1871 - 1994) of global sea surface temperature (SST) anomalies. By focusing on the 32-88 month and 18-35 month windows, we found that El Nino and La Nina had appeared in each of all tropical and extratropical ocean basins. The Antarctic Circumpolar Waves in Southern oceans can influence the occurrence of El Nino/La Nina in the tropics.

We have found El Ninos appearing in North Pacific, South Pacific, Indian Ocean, Equatorial Pacific, South Atlantic, and North Atlantic. Sometimes they appear simultaneously over all world ocean basins except Arctic and Southern Oceans. The same applies to La Nina. It is common that an El Nino appears in one ocean basin while a La Nina appears in another ocean basin.

We will show the live cycles of El Nino/La Nina using SST anomaly patterns. There are five categories of patterns: (1) Prototype, (2) World-wide, (3) Opposite El Nino-La Nina, (4) North Pacific + South Pacific, and (5) Antarctic circumpolar waves influence.