 ENSO - What is La Niņa?What is often referred to as "normal" in the atmosphere and oceans is actually just an average of many variations including extremes - over a long period of time. Thus, the El Niņo phenomenon itself is not anything freakish or "abnormal." It is related to the natural ebb and flow of the trade winds over the tropical Pacific. That, along with associated changes in atmospheric pressure across the Pacific, is known as the Southern Oscillation. The whole process is known as ENSO (El Niņo/Southern Oscillation). The opposite phenomenon to El Niņo is known as La Niņa or sometimes El Viejo. La Niņa, like El Niņo, is nothing unusual.The only atypical aspects of the recent El Niņo were its strength and early onset within the calendar year. The southern oscillation index (SOI), which is one measure of the phenomena, is rarely precisely at zero; rather it's usually trending in one direction or another. El Niņos and La Niņas are usually present, or coming/going. Both have been around for eons, and are a natural part of the complex physical world. | 
