An irregular variation of ocean current that from January to March flows off the west coast of South America carrying warm, low salinity, nutrient poor water to the south. It does not usually extend farther than a few degrees south of the equator, but occasionally it does penetrate beyond 12° S displacing the relatively cold Peru Current. The effects of this phenomenon are generally short-lived, and fishing is only slightly disrupted. Occasionally (in 1891, 1925, 1941, 1957-58, 1965, 1972-73, 1976, and 1982-83), the effects are major and prolonged. Under these conditions, sea surface temperatures rise along the coast of Peru and in the equatorial eastern Pacific Ocean and may remain high for more than a year, having disastrous effects on marine life and fishing. Excessive rainfall and flooding occur in the normally dry coastal area of western tropical South America during these events. Some oceanographers and meteorologists consider only the major, prolonged events as El Niño phenomena rather than the annually occurring weaker and short-lived ones. The name was originally applied to the latter events because of their occurrence at Christmas time.